Also, rear drum brakes create less drag than rear disc brakes. That allows for EVs like VW IDs with drum brakes in the rear to have more regen done at the rear wheels compared to disc brakes.
Drum Brakes have real advantages for EVs. As recuperation is always active in EVs, around 80-90% of the brake torque is anyhow done by the motor. Brake performance on rear axle is really not an topic in EV use case. Drum brakes have almost no drag torque (compared to a disk) and less particle pollution, brings more range,or less consumption and is environmental friendly. In the ID3 with Electric parking Brake it is designed for lifetime. From my persoective a perfect solution and a kind of reinvention of an „old“ brake technology perfect fitted to the needs of EVs. Unfortunately most people do Not understand it…..
Drum brakes can have better braking performance than disc brakes. But they very easily overheat so it's basically one or two time performance. But on other hand, how many emergency stops does one make? Especially today, we have a tire traction problem, not the braking performance problem.
Exactly. The only thing that I would change would be to have aluminium drums instead as it doesn’t corrode plus it would improve suspension comfort. I believe Honda CRX HF in the 90s had it.
@@sindresvindal2290 Drum brakes are typically made from cast iron or steel rather than aluminum for several key reasons: Thermal Conductivity and Heat Dissipation: Steel and cast iron have lower thermal conductivity compared to aluminum. This means that they can absorb and dissipate the heat generated by the friction between the brake shoes and the drum more slowly, preventing overheating and brake fade over time. Aluminum, while it can dissipate heat quickly, could lead to rapid changes in temperature that might affect brake performance and durability. Strength and Durability: Steel and cast iron have higher tensile strength compared to aluminum, which makes them more resistant to the stresses and strains experienced during braking. They are less likely to warp or deform under high loads, ensuring consistent braking performance. Wear Resistance: The braking action involves significant friction, and steel or cast iron has better wear resistance than aluminum. This means that drum brakes made from these materials will generally last longer before needing to be replaced or resurfaced. Cost: Cast iron is typically less expensive than aluminum, making it a cost-effective choice for manufacturing drum brakes. This is important in the automotive industry, where cost reduction is a constant goal. Coefficient of Friction: The materials used for making drum brakes are selected to have an optimal coefficient of friction with the brake shoes' lining material. Cast iron provides a good balance between performance and wear characteristics. While aluminum is used in some brake components, particularly in disc brake calipers and some high-performance or lightweight brake rotors, it is generally not used for drum brakes due to the reasons mentioned above. However, there are some applications, such as in racing or high-performance vehicles, where aluminum brake drums may be used for their weight savings despite the potential trade-offs in heat management, wear, and cost.
@@darekmistrz4364 yeah , any type of brake is perfectly able to lock the wheels but discs have the possibility to disipate heat marginally better (you know it would be "much better" imo when i will see fluid cooled brakes with fan radiators :P until then it disks just mean better airflow on a tiny area ) .
For a drum brake, VW actually used a pretty big size for the ID.3, but perhaps because it is an EV they figured they wanted to play it safe. You have to admit it was a smart solution to use "antiquated" tech like drum brakes on a car as pricey as the ID.3 but the engineering principle on keeping it long lasting due to regen brake is sound.
These videos in Valdemar's shop are a treat! It's always interesting to see the variety of mechanical issues that you guys are able to show. You guys are a great team.
Fascinating to see old braking technology being reused, but those drum brakes look almost brand-new inside! Can’t believe you can read all the part numbers! Our polo rear drums in comparison…
@@DoiPunctZero They are presenting the big advantage of drum brakes on EV. They dont rust at all which is a problem and brake rotors. Usually drum breaks perform worse but are cheaper for some reason. Thats why many smaller cars use drum brakes on the rear and brake rotors on the front.
Yes, drum brakes are not as good as disc brakes. Yes they are cheaper than disc brakes. BUT if you never use your brakes in your commuter car, it is a lot better to have NON RUSTING drum brakes than disc brakes which look like rust cake after 1 year
Drums on a car like this is a very good choice. Drum brakes have zero drag. They have very good braking performance. They are much better sealed compared to disks so they don't get pitted when you don't use them as much like on an EV. Where they actually suffer is cooling but since in a setup like this they don't see much action they are perfectly good enough. Another drawback can be that if water does pool inside and freeze they may lock up. On my car I have rear disks with drums inside for the parking brake. The drums inside and the parking brake are in perfect condition. The disks on the outside look like crap after two years and that's on a fossil car.
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Just use your brakes properly every once in a while. Even the rear discs look perfectly fine on my car, and they're eight years old. And we even get salt here in the winter. On EV's and hybrids the problem of brakes not getting used enough is of course bigger, so drums in the rear just might be a reasonable solution.
@@samijokinen9246 Rusting disks should not be an issue in normal driving. if you go down any sort of hill or brake from 60mph once a week you've cleared ALL rust away. unless you drive like a grandma and engine brake everywhere... also brakes are much cheaper than ANY part of an engine
@@karlInSanDiego exactly, use the brakes even lightly each drive and the rust on the discs will be gone (same as ICE) but with the benefit of less wear from regen braking! At 4 years 80k kms I took my ev brakes apart to tidy up and lubricate, no replacement parts needed, and that’s with spirited driving
There is no problem with drum brakes... Until the cover plate starts to rust, an parts of it falls of.. Especially the edges, but that takes decades. Then there is the automatic adjustment, and everything else starts to set, cause the brakedust accumulate inside.
Drum brakes are not entirely maintenance free. As u could see, dust builds up in the drums and needs to be removed from time to time. This ID3 is quite new but after years the springs will rust and retract poorer which increases drag. Discs are exposed but u can see if there is rust on it and brake excessivly or drive a while without regen if possible.
I had to have my i-pace rear disks replace after 4k miles, it was a demonstrator during Covid so did the same journey every day. I keep them clean by going into neutral down a hill near my home and using the brakes to slow down 👍
Same. There's a long, fast hill I drive weekly so I put the car in neutral at the top and brake gently on the way down coming to a stop at the junction. It keeps the friction brakes rust free.
Yes, it is very much the driving style... We were driving our i-pace on german motorways (sometimes with heavy foot), we head no rust issues in nearly 4 years
@Quarks and @Martyn please don't coast in neutral to clean your brakes, you may find yourself in an emergency situation without full control of your vehicle which would be bad. I would also like to draw your attention to highway code rule 122 www.gov.uk/guidance/the-highway-code/general-rules-techniques-and-advice-for-all-drivers-and-riders-103-to-158 Not being an EV driver myself this may be bad advise but you can generally clean up/re bed your discs with a couple of moderate decelerations from about 60 - 70mph down to about 30. You may need to stray into the "hard braking" territory if you're an EV driver as I dont know when the cutover is from regen to regen+ brakes. In an ICE car you can just drag the brakes for a couple of meters and they will do the good.
The procedure from min 3:00 is not necessary in my ID.3. i sit in the car, press the brake and put the gear in N. The car asks me if i want to deactivate the roll-away protection. If i confirm i can get out of the car, close the door and maneuver the car per hand.
Fun video....as an old guy in Canada, pretty much all our older cars ( pre 80's) had drum brakes and not just on the rear. I still own and drive some classic MGB's and they still have rear drum brakes. Not a bad idea for the rear of a smaller lighter EV actually. In the area I live in they use an extraordinary amount of salt on the roads and a couple of winters of use in the old days and the undercarriage of our cars get pretty corroded. Great video and Merry Christmas!!!! Mike 🇨🇦 🍁
The drum break friction material is a pain in the Axx to replace. The break dust get trap in the housimg is not helping either. Last thing I wanna happen is a plume brake dust blown towards me When I pull the casing off.
@user-jh6vt8vx4v I've done hundreds of drum brake repairs/replacements, not that bad, wear a respirator, gloves and vacuum the brakes with a HEPA filter bag in your shop vacuum, spray area down with brake cleaner and you're covered. No big deal, in any case there is brake dust and crap in the disc brakes as well....not as much as drum brakes for sure, but it is still there. Besides, on an EV likely won't have to do brake replacements for a long, long time anyway! Merry Christmas Mike 🇨🇦 🍁
@@michaellippmann4474you are right on EV brake pad life span. Despite heavier car, the the regen helps alot. But frequent short distant commue in cold climate may diminish this advantage to a degree due to energy recover is not working at full effective when battery is cold. But it should be still able to last over 100k under sensible driving compare to 70k ish on ICE car. Merry Chrismas
My mark I mini had drum brakes. It also lacked brake assist so was fundamentally useless. On a more positive note -it was the only bit of the car which didn't suffer in wet weather, unlike the ignition
Valdemar is a great guy! BMW i3 I recently had to replace all 4 discs and pads due to rust to pass EU. Not worn out. 75000 km. It costed me 14000 NOK. I try to break hard from time to time
I know all of the pros for using drums on an EV or hybrid car but that groove in the brake shoes???? You won’t be able to give the drums a few wakes to free it up after a certain point and will be forced to de-adjust the shoes to just get the drums off!
The old VW Beetle had drum brakes all round. The drums have some self boosting capacity, but they cannot dissipate heat as quickly as disc brakes. On bicycles and light mopeds they turn the drum brake mechanism around so they have anti-boost preventing wheel lock up and falling. I am a big fan of drum brakes for lighter and "commuter" cars. I have a Mitsubishi 2015 Space Star (Mirage) and it has drum brakes in the rear. They are almost maintenance free and trouble free whilst the front discs have been replaced already.
That is because your brake bias is set at 70f and 30 B. Lol of course it is lasting lot longer. The rear drum brake is used more for park. My 05 civic has drum in the back, it is always the front lock up when I blow the brake padle
On EVs there's not much need for high heat dissipation, since the mechanical brake is just for emergency stops. Everything else is mostly done by regen braking. This is what a lot of people in the other comments don't understand
Italian Tune-up in dino juice cars is hard acceleration to dislodge carbon build-up in the engine, followed by hard breaking to de-glaze the brake pads and clean the rotors. Sounds like EV's can do with a little bit of this as well occasionally. Rear Drums are still the best type of brakes for normal commuter vehicles
de-glaze? ok you got that totally backwards, there is no de-glazing unless you mill the brake discs. hard braking can lead to overheating which causes glazing. common on trucks where drivers use incorrect braking techniques.
thanks for the informative video. it was also my first look inside a drum brake and it's good to see that they are in perfect condition. i'm curious to see how long the front brake discs and the rear drum brakes will last on my id.4 gtx.
3:09 In the Skoda Enyaq, you can stop, put the car back in N, then a message appears at the top of the screen asking you if want to keep the car in N. If you press that, you can work on the car as long as you keep the "ignition" on. Should be the same with the ID3 since the cars are quite similar 🤔
In my e-208, I found that when I shift to N, the regen is completely off even when pressing the brake pedal. I use it to clean the brake rotors from time to time, especially after driving in wet or snowy conditions. I pick up some speed, shift to N and brake semi-hard. Also the parking brake toggle when pulled acts as an emergency brake, braking with the rear brakes only. Those need cleaning a bit more, the parking brake can otherwise get a bit sticky due to rusting and release with a loud clunk when driving off. I tend not to apply the parking brake when a risk of that is elevated (like after a rainy drive) when parked on a level surface, the motor P lock is enough. Oh, I'd love to have rear drum brakes! Makes even more sense on a RWD car where regen is on the rear, but the front gets used at least a bit.
couldn't you use the accelerator and the brakes at the same time for a couple hundred metres every week? that'd keep the discs shiny. this seems to me like a software problem. they could even schedule a brakes maintenance mode that does this automagically
I've tried that on my Cupra and it doesn't work, if you press brake it automatically starts regen with the electric motor. But if I put the gear in neutral no regen is applied when braking.
They're a perfect choice on EVs for the rear axle where you anyway (in any vehicle type) need only a lot less braking power than on the front axle. Replacement is also cheaper, and often you can get away with just replacing the shoes/springs and not the drum. The issue with drum brakes is bad heat dissipation (again, not too much of a problem on the rear axle) which can in extreme cases lead to a lockup of the brake (also contamination of the shoes or a defective cyclinder might trigger that).
About those rear drum brakes on the ID3 it is best to have the single piston, so the shoe can either hold the car from running forward or hold on a hill from running back. When it is two leading shoes they are powerful in going forward but much less back. I wish manufacturers would use some other disc material. Maybe a version of Carbon, so they don't rust. Best Dave
Bjorn, thanks for this! Two tips… first, you can get the ID. Cars to stay in Neutral by shifting them to Neutral, then agreeing to a message on the center screen (aka Car Wash mode). And second, there’s no need to drive fast and brake hard - the easiest way to clean the brakes is just drive a low speed, shift to Neutral, and step on the brakes gently… especially going down a hill. In Neutral, regen is disabled.
Hi Bjorn I was looking at few days ago in my part’s catalog for a 2023 Canadian spec iD4 for rear brake parts prices and the hydraulic wheel cylinder are $ 30.00 each the drums are $ 70.00 each and the brake shoes are $ 120.00 for the set I remember when doing rear brakes on older VW that was driving on mix toads the shoes would last 200 000 km what I like is the Parking cables are not uses anymore they are motor that actuates the rear drums all the price that I mentioned is in Canadian currency. The only downside to drums is if the drums are too worn the brake pedal will be lower.
I have a Cupra Born and I put the gear in N sometimes to remove the rust from the disc brakes. Then there is no regen and only normal brakes are used. I guess this works on all cars on the MEB platform, I don't know if it works on other brands though.
German but what a shit, from the beginning I have problems with the electric handbrake in my ID3 1st, it stucks/blocks almost everyday in wet conditions (Im Basque not German so u can imagine that weather in those terms its worst in the design country that in mine), When u release it putting the gear selector on D or R its blocked and you have to force it to run , I reported to my VW dealer like 5 times in those years till the handbrake finally as broken and the car was stopped for his security. 4 months in the garage cause the rear brakes handbrake was broken and were not spare parts for it, 4 months !! After that period they changed the servo and the actuator but not the drum pads which is the part that has contact with drums, so clever Vw!! So the problem continued as before, I reported but they never answered, you don't need to be a German engineer to guess that if the pads are bonded to the drums every wet day maybe the pads are the problem? I tell them to change the pads that I payed and problem its solved. Thats is not an electric car issue, its a general car issue. This was my 5th VW/Audi and the last.
Small cars with rear discs often rust their rear discs more than larger cars as they aren't heavy enough to get adequate load to clean surface rust thoroughly during braking, especially if the car isn't in regular use. Bias valves and ABS will be preventing brake lock up on a light car under hard braking. I use the cable operated handbrake a bit during driving to clean my rear discs of surface rust if I leave either of my cars unused for a while, one of which is fairly small and light the other not as small and light but it's use is less. This seems to do the trick for me. Neither are EV's but the principle is there for rear disc equipped cars regardless.
I think the best way to take care.of brakes is from time to time do a friction only braking: coast, switch to neutral and do normal braking without regen (it won't work on neutral)
Or, you have a car that uses the rain sensor to predict moisture on the brake and applies them with minimal contact to dry and clean them. The customer should not be required to do strange driving in public.
@@AlbertLamarque even ignore the sensor and from time to time reduce regen and do friction braking instead. Can be done with car's software. Probably will be a standard in future.
I know this is a different subject but I had to replace all my pads and discs on my three year old Arteon after only 16k miles, and I'm an older, steady driver. Discs were in an appealing state.
Brakes need to be used fairly hard frequently to not just rot away, if all you’re really doing is putting about town mostly engine/rolling resistance braking then the brakes will rot for the same reason EVs do.
@@MrAdopadoDon't be surprised if Google is spelling for you! Sometimes it's "interesting" to know which letters are close to each other on the keyboard. I press 5 instead of t "many" times on my pad...
@@leiflillandt1488 Yep, don't I know it! In this instance it was a fantastic typo example because it described the exact opposite of what was intended!
👍🏼👍🏼 I wish ly GTE would also have drum breaks. I had to get new disks for front and rear because they were so rusty since I used to drive 90% in B gear, now once a week I put the car into neutral and do a hard breaking from 80-100 to 0 since then it uses the disks, no regen to ”clean” the disks
It can be much more economical to have no regen and just roll, and then brake. Regeneration has its losses as well. Harder regen have more heat loss. Obviously if driving down a long hill you'd use regen to keep from speeding, much like low gear to brake via engine on old ICE cars. You can drive a long way for the price of new brake disks. So even if it sounds less economical to not regen it might not be in the long run.
@@Gazer75I thought the current set of EVs were adopting a profile of explicitly working the disk brakes from time to time; will have to check. Otherwise, yes, some manual intervention is required. A bit like on every cycle ride on a bike with hydraulic disk brakes I need to pump the brake levers whenever I set off to force any air bubbles up from the piston into the reservoir in the brakes. Just another habit to adopt
I had the same on my GTE, factory brakes lasted 3 years. However I got some good quality low corrosion replacements and they lasted 5 years with no obvious sign of wear.
If you use D or B doesn't really make a difference in the GTE. Yes, it doesn't regen when you take your foot of the accelerator, but once you step on the brake it will do max regen possible before engaging the brakes. It actually has a brake cleaning mode. After accelerating and braking hard twice, it will no longer engage regen for a little while. This allows you to clean the discs much easier, but the rear discs are still an issue. I bought my GTE with 3 years/20,000km, and it needed new rear brakes immediately. Tried cleaning them, but the corrosion was too severe, they never cleaned up.
The front tires kick up all sorts of spray and crap. That is why drums in the back are better for regular passenger cars. For maniac driving you might want discs.
I find drum brakes to be pretty good. They need to be set up correctly to work properly, so more finicky than disc brakes. The best advantage though is that drum brakes has zero drag. That they overheat easier is not really a problem for most people unless you drive on a race track or drive down a mountain and use the brakes instead of engine braking…
Harder to engine brake on an automatic or EV, but I've found cruise control to work well when doing big mountains to set that steady rate for the straight parts. This also stops my car having the "tourist lights" on as my Munich-based friends to use to describe brake lights on vehicles from north Germany doing alpine roads with the brakes on all the way....
The surface rust on the outside of drums is just cosmetic - my VW UP came painted grey and a coat of wax prolonged the life. Easy to respray or coat with rust protector too because no risk of contaminating the enclosed brake surface or friction material
Something I really don't like with many european cars is that they often have wheels mounted with bolts instead of nuts you screw on threads that makes shifting wheels so much easier, especially with thick aluminum wheels.
I don't have an issue with the drum brakes on our Born. One benefit that often gets overlooked is that the brake particulate is confined inside the drum and so less likely to enter the environment. Not the case with discs.
@@Chris675R Thanks for stating the obvious. My point was, (which seems to have passed you by) is that removing the dust and particulates in the workshop will reduce the likelihood of it being dispersed around the environment and ending up in the places it shouldn't be as the car travels around.
@@MartynDews Well, where do you think the mechanic will go, if he will clean out all the dust with the compressed air? He will certainly not do it in the shop, so all the people in there have to breathe in that healthy dust. He will go outside or at least hold it out of the window and release it into the air. In theory you are right, while braking on the road, the drum brakes contain the brake dust, but it will be released into the air anyways, if the brakes are being serviced.
Drum brakes are as good as disc brakes in their ability to turn motion into heat. Their biggest problem was to disperse the heat, because heating expands the drum, and the brake shoes run out of travel trying to chase the receding drum's surface. Another difficulty is the brake shoe itself, which can also overheat and 'glaze' the braking surface. This is a chemical transition that decreases the friction (turns it into a form of glass), which also diminishes the effectiveness. Both situations can be designed out, but with simple disc brakes, isn't worth the effort. They are, however' very inexpensive to manufacture, as well as very reliable. Since very little braking is done by rear brakes (because the centre of gravity moves forward under braking), they are never overloaded. The rear brakes also are the most convenient to use as parking/emergency brakes. The design used on the ID3 gives equal braking both forward and backwards, as well as a self-adjustment mechanism. The central groove is another feature with two benefits. The first is to provide shorter routes from brake dust created by wear, to get out from between the shoes and the drums in normal use (infrequent heavy braking by the rear brakes). The second reduces the friction surface and thus enables a harder braking compound to be employed, while not reducing the effectiveness of the design in the process. This gives a longer service life to the rear brakes, which might match the life of the front discs as far as servicing goes. I understand that VW has been experimenting/employing a slip-seal around the edge of the drum and back-plate to exclude the opportunity for water and debris to enter the mechanism, but, self evidently, this seems unnecessary if you consider this car's experience.
How about difference in braking force between left and right rear drumbrakes? Mine was almost out of spec being at the TÜV inspection after 3 years (45000km)....
Even on my Golf IV, I had trouble getting the rear brakes to pass more than two semi-annual MOTs/EU controls in a row. Rusty brake discs was always a problem, and on an EV the problem would be even worse. So I'm very happy my ID.4 has drums in the rear - they're just a lot more hassle free.
@@philipp5183 You didn't get the message in this video or in what I wrote at all, did you? Drum brakes on the rear is the better solution because discs are complete overkill. It's got oodles of regenerative braking on the rear. Rear discs would just sieze and rust.
Only problem with drum brakes on old cars that had them would be failed hydraulic seals. These would allow hydraulic fluid to leak on to the brake linings. Not a pleasant job on old cars with asbestos dust that you had to remove from the drum ... or black sludge if it was mixed with hydraulic fluid! In principle it seems a reasonable choice of braking system for the rear on an EV.
Break size is determined by car mass for homologation, so heavy EV cars will have unusually big brakes. To prevent EV disk brakes from rusting, make harder breaking from time to time especially in wet conditions, or the best the next day after car wash or rain. It will clean the rust and prolong disk lifetime. Drum brakes are better sealed, not exposed to water so much, so this is one of the reason they are used for EVs.
What i would have done is give the drums a clean with brake cleaner , Also on contact surfaces that have corrosion sand them down with a wire brush and apply a generous amount of copper slip grease . Then that would be sorted 😀
It is cost cutting, but not in the way you think - the cost cutting is for the owner mostly. This is because the rear brakes are almost never used, only in full emergency. The ID3 has the electric motor in the rear. When you are braking even quite hard, then first the friction brakes apply in the front, because that is where the majority of the braking force comes from. The front does about 70-80% of the braking, and the rear only has to do 20-30%. In most cases the electric motor is enough to provide this amount of braking in the rear and the rear brakes do nothing. If they fitted standard disc brakes they would either need to install really expensive special rotors that do not rust easily, which would drive up the price of the car, or if they fitted standard parts you would have to replace them every year, since they'd get completely rusted, as they are never used. If the electric motor was in the front, then they would have fitted disc brakes in the rear. Tesla for example does not have this "problem" because Tesla still can't do brake blending even today. So every time you touch the brake pedal both the front and rear brakes are physically engaged. This is not the case on the ID3, where in the beginning of travel the brake pedal only engages the electric motor, and not the friction brakes, then the front brakes are phased in and in the very very end if absolutely necessary (near full emergency stop) come in the rear friction brakes.
On our 2017 Chevy Bolt EV, we found out the hard way, to put the car in neutral once a day or two - and use the friction brakes only - to clear the rust.
Unless you do track driving, no passanger car needs disk brakes for rear for speeds that most countries allow. Rear wheels do not have enough traction to warrant disk brakes for the brake power but drum brakes are slow to release heat so if you do multiple heavy braking actions in series, the drum brakes may overheat and brake shoes no longer work well.
@11:20 Best thing you can do is to have no regen if not driving long down hills and actually use the brakes. Yes some, if not most, EVs will regen with light braking, but if you press harder they do apply friction brakes. Dealers often recommend to brake hard once a week during winter, especially if its raining and not much salt is on the road. Even in summer if its raining a lot it can be a good idea to brake hard every so often to avoid rust buildup. I always drive with no regen and brake harder every so often during the salt season to make sure brake pads don't rust.
Hello from Germany, I am questioning myself why you have brakes at all in Norway? Being there 2020 with our Pickup Camper we only met obstacles on the roads, driving so slow and with all the bumps and speed limits everywhere, no need to brake, most times I used the indicator to pass you 😂
It was one of my many reasons for getting rid of the Kia Niro EV. I braked hard 3-4 times on my way home from work, drove a bit past my house and reversed at max speed slamming the brakes while using the "clean brake discs" mode, and even then my rear discs were rusty. Crap quality, but why not just put a drum brake in there. Even with the Picanto/I10, they had rear discs. Completely unnecessary.
That's a good point, but I think EVs also lock the transmission when the parking brake is applied. Never heard of an issue with Teslas slipping their parking brakes?
I thought I was alone to prefer drum brakes for their rustproof qualities. I have to replace discs every 3 years on both my Saturns that's why I hate disc brakes. Semi trucks use drum brakes on all wheels in North America. Big truck companies have resisted the change to disc brakes because of their higher maintenance cost. They understand this consumer trap.
Brake shoes can provide more braking effort than brake pads and discs, the only real disadvantage with shoes and drums is that brake dust builds up and because they are enclosed they don’t dissipate heat as well as discs.
I have never seen drum brakes this big on a small car. These probably have more braking force than same diameter discs because of the larger contact area between the shoes and drum compared to a single caliper. Also the entire friction area is farther out than a disc, which relies on friction at a shorter radius from the center. Hand brake actuation is probably also easier to integrate into drum brakes. The downside is the wear parts are hidden from visual inspection and they have reduced cooling comparead to discs, but cooling is not an issue on electric cars.
I can't remember exactly who said it when, but one of the engineers at Tesla said that they use a custom material for their brake discs which is more corrosion resistant. Can confirm as a Tesla owner, apart from a tiny bit of surface rust after a rainy day, there is no serious corrosion on them. For a non-performance car, I think drums are a great Idea for EV's as you dont have to worry about corrosion at all. Also potentially saves money by having a mechanical handbrake using the rear drums
the brakes are under ABS anyway, and the ABS can be programmed to make the brakes feel like however you want them to feel so it can feel 'sporty' , but you cannot drive 'sporty' for very long because of the heat buildup
In my opinion, VW hasn't made a bad decision here - at least for the smaller and weaker models, completely sufficient, since the recuperation takes place on the rear axle anyway and can also be better regulated. However, I see practical problems with the large, heavy models: The trailer load is therefore much lower. The ID series only has around 1200 kg for braked trailers. It's particularly bad with the ID Buzz, which has an empty weight of over 2400 kg but is only allowed to tow 1000 kg. Completely unusual if you compare it to a T6 and its 2500 kg.
I think the trailer load is limited by the motor cooling mostly, not brakes. Because those VW EVs are heavy they do not have sufficient cooling to add a lot of additional towed mass.
@@UhOhUmm EVs overall have bad towing capacity, my parents Subaru Solterra only has 750kg capacity meanwhile my E-tron does 1800kg which is decent enough but still quite a bit lower than what a Q7 3.0 TDI can tow(3500) for example. Even the Tesla X is quite limited at only 2250kg comparatively.
drum brakes are cheaper to produce and lighter in total (that might surprise you), which is veeeery important in weighty EVs. This weight is why ID.3 with bigger battery has only 4 seats. Drumbrakes are less frequently to maintain but when you have to maintain them, this guy with hammer is going to charge you significantly more (changing a break pad is so easy ...). The trouble is ID.3 is not cheaper than TM3, so the savings do not go to customer's pocket.
oh no please open the electronic parking brake via the Diagnose port and set it in Service mode Drum brakes tend to fade much quicker, but because you have regen on the rear axle and if you brake hard mostly the front brake is doing the job, so this is no problem. You are not driving on the race track where you have constant braking
They aren't just better for rust - calipers can stick/seize often in salted road conditions but in the drums they are mostly protected. The I.D is a rear drive3 car so rear regen also. That means the brakes are large incase of emergency stops but most other times they are hardly used. Disks are only better for heat dissipation but on most ev's thats never going to be a problem anyway since you can't push them hard enough for long enough to get the rears to cook anyway. They are certainly a better choice for this application.
Don't mind the rear brakes being drums since regen should keep them from overheating, but I wish VW would use steel-lined Aluminum drums to drop unsprung weight.
@@retiredbore378 You mean galvanic corrosion, which is preventable. From what I can find of weights, it seems like drums are ~15lb/corner. Saving even 20%, so 3lbs/corner unsprung, is huge. Granted, OEMs don't seem to agree, judging by the stock disc brake parts and wheels they spec.
@@retiredbore378 Galvanic is a different type of corrosion requiring an applied voltage, not just a different name. As for the unsprung weight, I'd expect it to be 75-100lb/corner. I don't know about the hub/knuckle in particular.
I have a question 2 years ago I took My ID3 to workshop for first service They said no need to replace break pads /shoes Now it almost 3 years with 40,000 km range Do I need to be worry about my break pads wearing? Because my first EU control is around 7-8 months next Because some days in the mornings the breaks was locked and I car moved very hardly
Ah thanks I was looking to se if someone had written about possible negatives of drum brakes. I'm guessing they are a little bit more expensive in production as well?
That is what normal car needs too, the slide pins cost like $1 for normal cars, so better replace them. The worst part here is we use salt on the roads, so lots of rust everywhere. And the pads can get stuck where they are supposed to glide.. making only one of the pads engage when braking.
@@AndrewTSq I have the same salt usage in Michigan. This summer I pulled my calipers and polished and greased the pins. I didn't check how much new pins would cost plus the drive to the Service Center. They'd need to come out either way.
@@eb1888. I do it once a year with my old Volvo, never had a caliper seize. Quick job when you are changing the tires. Unbolt the pins and run them on the wire brush, lubricate and remount.
Alternative routes and speed cameras are probably the best part of this update, blindspot indicator light is not bad but the way tesla does blindspot detection isn't very good, even for the new highland, 1 day they'll make something good/innovative for blindspot detection, I hope. What would have been nice is the fabled tesla app store that was rumored awhile back. Plus maybe in the not too far future Tesla will redesign the voice commands into a voice assistant (Alexa but orders of magnitude better) which can function the car and help you with anything like banking, groceries, questions etc..
@@testi2025 It hink that is not the whole truth. The mechanical brakes are used, when the electrical brakes are not strong enough- If you are a defensive driver (like me) i expect nearly no usage of physical brakes. If the battery is fill (100%) or the car is in neutral, than you are right-
@@ndc5544p Probably. From my point of view, it is a question of strategy. So maybe, there are differences from Car to car. Even the much heavier cars like ID4 might be different to the ID3.
drum brakes are perfect for cold climates like Norway has... Here in greece where we have hot climate when they get hot they underperform because they have poor ventilation in compare to disk brakes ....
@@bjornnyland I don't own an electric car.. I have a car which has drum brakes in the back wheels and in the summer in long and steep downhills they have problems overheating and don't brake properly..
Why not have a sacrificial metal (anod is it?) on the cars that run in countries that salt the roads or in citys by the sea? Like you do on metal parts on boats.
As others have said, the ID cars already have regen on the back wheels, so low maintenance drum brakes is just good engineering on the part of VW.
IDs are RWD?
@@antoniocirino8444yep, rwd only. At least for now
@@antoniocirino8444 ID.3 are all RWD. The ID.4, Enyaq, Q4 e-tron & ID.5 are either RWD or AWD depending on model.
Also, rear drum brakes create less drag than rear disc brakes. That allows for EVs like VW IDs with drum brakes in the rear to have more regen done at the rear wheels compared to disc brakes.
Drum brakes is probably the best engineered part of the whole ID line-up...
Drum Brakes have real advantages for EVs. As recuperation is always active in EVs, around 80-90% of the brake torque is anyhow done by the motor. Brake performance on rear axle is really not an topic in EV use case. Drum brakes have almost no drag torque (compared to a disk) and less particle pollution, brings more range,or less consumption and is environmental friendly. In the ID3 with Electric parking Brake it is designed for lifetime. From my persoective a perfect solution and a kind of reinvention of an „old“ brake technology perfect fitted to the needs of EVs. Unfortunately most people do Not understand it…..
Drum brakes can have better braking performance than disc brakes. But they very easily overheat so it's basically one or two time performance. But on other hand, how many emergency stops does one make? Especially today, we have a tire traction problem, not the braking performance problem.
Exactly. The only thing that I would change would be to have aluminium drums instead as it doesn’t corrode plus it would improve suspension comfort. I believe Honda CRX HF in the 90s had it.
@@sindresvindal2290 Drum brakes are typically made from cast iron or steel rather than aluminum for several key reasons:
Thermal Conductivity and Heat Dissipation: Steel and cast iron have lower thermal conductivity compared to aluminum. This means that they can absorb and dissipate the heat generated by the friction between the brake shoes and the drum more slowly, preventing overheating and brake fade over time. Aluminum, while it can dissipate heat quickly, could lead to rapid changes in temperature that might affect brake performance and durability.
Strength and Durability: Steel and cast iron have higher tensile strength compared to aluminum, which makes them more resistant to the stresses and strains experienced during braking. They are less likely to warp or deform under high loads, ensuring consistent braking performance.
Wear Resistance: The braking action involves significant friction, and steel or cast iron has better wear resistance than aluminum. This means that drum brakes made from these materials will generally last longer before needing to be replaced or resurfaced.
Cost: Cast iron is typically less expensive than aluminum, making it a cost-effective choice for manufacturing drum brakes. This is important in the automotive industry, where cost reduction is a constant goal.
Coefficient of Friction: The materials used for making drum brakes are selected to have an optimal coefficient of friction with the brake shoes' lining material. Cast iron provides a good balance between performance and wear characteristics.
While aluminum is used in some brake components, particularly in disc brake calipers and some high-performance or lightweight brake rotors, it is generally not used for drum brakes due to the reasons mentioned above. However, there are some applications, such as in racing or high-performance vehicles, where aluminum brake drums may be used for their weight savings despite the potential trade-offs in heat management, wear, and cost.
@@darekmistrz4364 yeah , any type of brake is perfectly able to lock the wheels but discs have the possibility to disipate heat marginally better (you know it would be "much better" imo when i will see fluid cooled brakes with fan radiators :P until then it disks just mean better airflow on a tiny area ) .
For a drum brake, VW actually used a pretty big size for the ID.3, but perhaps because it is an EV they figured they wanted to play it safe. You have to admit it was a smart solution to use "antiquated" tech like drum brakes on a car as pricey as the ID.3 but the engineering principle on keeping it long lasting due to regen brake is sound.
Just cost reduction.
@@popaovidiu3282 Maintenance cost reduction, yes. For parts costs, probably not.
-- get a Chargehanger
ID4 also use drum brakes! But for this low Power EVs ist fine
@@sebastiankiesl1395Nothing to do with power. Dimensionning is in regards of weight and max speed.
These videos in Valdemar's shop are a treat! It's always interesting to see the variety of mechanical issues that you guys are able to show. You guys are a great team.
Fascinating to see old braking technology being reused, but those drum brakes look almost brand-new inside! Can’t believe you can read all the part numbers! Our polo rear drums in comparison…
It's cheaper, that's why it's used.
@@DoiPunctZero no, because it's an EV, the disks are taking rust because they're almost never used, like on every Tesla...
Look at a Toyota after 10 years, same thing.
@@DoiPunctZero They are presenting the big advantage of drum brakes on EV. They dont rust at all which is a problem and brake rotors. Usually drum breaks perform worse but are cheaper for some reason. Thats why many smaller cars use drum brakes on the rear and brake rotors on the front.
Yes, drum brakes are not as good as disc brakes. Yes they are cheaper than disc brakes. BUT if you never use your brakes in your commuter car, it is a lot better to have NON RUSTING drum brakes than disc brakes which look like rust cake after 1 year
Drums on a car like this is a very good choice. Drum brakes have zero drag. They have very good braking performance. They are much better sealed compared to disks so they don't get pitted when you don't use them as much like on an EV. Where they actually suffer is cooling but since in a setup like this they don't see much action they are perfectly good enough. Another drawback can be that if water does pool inside and freeze they may lock up. On my car I have rear disks with drums inside for the parking brake. The drums inside and the parking brake are in perfect condition. The disks on the outside look like crap after two years and that's on a fossil car.
Just use your brakes properly every once in a while. Even the rear discs look perfectly fine on my car, and they're eight years old. And we even get salt here in the winter.
On EV's and hybrids the problem of brakes not getting used enough is of course bigger, so drums in the rear just might be a reasonable solution.
@@samijokinen9246 Rusting disks should not be an issue in normal driving. if you go down any sort of hill or brake from 60mph once a week you've cleared ALL rust away. unless you drive like a grandma and engine brake everywhere... also brakes are much cheaper than ANY part of an engine
These EV rust videos are very valuable 👍
@@karlInSanDiego exactly, use the brakes even lightly each drive and the rust on the discs will be gone (same as ICE) but with the benefit of less wear from regen braking!
At 4 years 80k kms I took my ev brakes apart to tidy up and lubricate, no replacement parts needed, and that’s with spirited driving
There is no problem with drum brakes... Until the cover plate starts to rust, an parts of it falls of.. Especially the edges, but that takes decades.
Then there is the automatic adjustment, and everything else starts to set, cause the brakedust accumulate inside.
If VW suckers enough idiots into going back to drum brakes, their marketing team all deserve huge raises.
Drum brakes are not entirely maintenance free. As u could see, dust builds up in the drums and needs to be removed from time to time. This ID3 is quite new but after years the springs will rust and retract poorer which increases drag. Discs are exposed but u can see if there is rust on it and brake excessivly or drive a while without regen if possible.
I had to have my i-pace rear disks replace after 4k miles, it was a demonstrator during Covid so did the same journey every day. I keep them clean by going into neutral down a hill near my home and using the brakes to slow down 👍
Same. There's a long, fast hill I drive weekly so I put the car in neutral at the top and brake gently on the way down coming to a stop at the junction. It keeps the friction brakes rust free.
Yes, it is very much the driving style... We were driving our i-pace on german motorways (sometimes with heavy foot), we head no rust issues in nearly 4 years
@Quarks and @Martyn please don't coast in neutral to clean your brakes, you may find yourself in an emergency situation without full control of your vehicle which would be bad.
I would also like to draw your attention to highway code rule 122
www.gov.uk/guidance/the-highway-code/general-rules-techniques-and-advice-for-all-drivers-and-riders-103-to-158
Not being an EV driver myself this may be bad advise but you can generally clean up/re bed your discs with a couple of moderate decelerations from about 60 - 70mph down to about 30. You may need to stray into the "hard braking" territory if you're an EV driver as I dont know when the cutover is from regen to regen+ brakes. In an ICE car you can just drag the brakes for a couple of meters and they will do the good.
The procedure from min 3:00 is not necessary in my ID.3. i sit in the car, press the brake and put the gear in N. The car asks me if i want to deactivate the roll-away protection. If i confirm i can get out of the car, close the door and maneuver the car per hand.
Cheaper for the manufacturer and more business for the dealership when the automatic adjusters corrode and screw up.
Fun video....as an old guy in Canada, pretty much all our older cars ( pre 80's) had drum brakes and not just on the rear. I still own and drive some classic MGB's and they still have rear drum brakes.
Not a bad idea for the rear of a smaller lighter EV actually.
In the area I live in they use an extraordinary amount of salt on the roads and a couple of winters of use in the old days and the undercarriage of our cars get pretty corroded.
Great video and Merry Christmas!!!!
Mike 🇨🇦 🍁
The drum break friction material is a pain in the Axx to replace. The break dust get trap in the housimg is not helping either. Last thing I wanna happen is a plume brake dust blown towards me When I pull the casing off.
@user-jh6vt8vx4v I've done hundreds of drum brake repairs/replacements, not that bad, wear a respirator, gloves and vacuum the brakes with a HEPA filter bag in your shop vacuum, spray area down with brake cleaner and you're covered. No big deal, in any case there is brake dust and crap in the disc brakes as well....not as much as drum brakes for sure, but it is still there.
Besides, on an EV likely won't have to do brake replacements for a long, long time anyway!
Merry Christmas
Mike 🇨🇦 🍁
@@michaellippmann4474you are right on EV brake pad life span. Despite heavier car, the the regen helps alot. But frequent short distant commue in cold climate may diminish this advantage to a degree due to energy recover is not working at full effective when battery is cold. But it should be still able to last over 100k under sensible driving compare to 70k ish on ICE car. Merry Chrismas
My mark I mini had drum brakes. It also lacked brake assist so was fundamentally useless. On a more positive note -it was the only bit of the car which didn't suffer in wet weather, unlike the ignition
@@林振华-t4v Merry Christmas to you as well!
Valdemar is a great guy! BMW i3 I recently had to replace all 4 discs and pads due to rust to pass EU. Not worn out. 75000 km. It costed me 14000 NOK. I try to break hard from time to time
You could just brake 100-0 several times on an empty road, it would remove the rust for free
I know all of the pros for using drums on an EV or hybrid car but that groove in the brake shoes???? You won’t be able to give the drums a few wakes to free it up after a certain point and will be forced to de-adjust the shoes to just get the drums off!
The ”disc” is called brake drum. If someone is wondering.
? Why don't they use anti rust brake materials like GM has on certain EV's.
Even in Australia, we can get Dba brake rotors that don't rust like those.
Facelifted Zoe has discs in the rear.
Its purely a manufacturing cost saving activity, nothing to do with the end user's savings in maintenance.
The old VW Beetle had drum brakes all round. The drums have some self boosting capacity, but they cannot dissipate heat as quickly as disc brakes. On bicycles and light mopeds they turn the drum brake mechanism around so they have anti-boost preventing wheel lock up and falling. I am a big fan of drum brakes for lighter and "commuter" cars. I have a Mitsubishi 2015 Space Star (Mirage) and it has drum brakes in the rear. They are almost maintenance free and trouble free whilst the front discs have been replaced already.
That is because your brake bias is set at 70f and 30 B. Lol of course it is lasting lot longer. The rear drum brake is used more for park. My 05 civic has drum in the back, it is always the front lock up when I blow the brake padle
On EVs there's not much need for high heat dissipation, since the mechanical brake is just for emergency stops. Everything else is mostly done by regen braking.
This is what a lot of people in the other comments don't understand
Italian Tune-up in dino juice cars is hard acceleration to dislodge carbon build-up in the engine, followed by hard breaking to de-glaze the brake pads and clean the rotors. Sounds like EV's can do with a little bit of this as well occasionally. Rear Drums are still the best type of brakes for normal commuter vehicles
😂Depends on the driving behavior. I need to use the brake on my model 3 at least once a day.
de-glaze? ok you got that totally backwards, there is no de-glazing unless you mill the brake discs. hard braking can lead to overheating which causes glazing. common on trucks where drivers use incorrect braking techniques.
Its nearly the same in my Seat Mii Elektro, works great in you pull the Hand break sometimes.
thanks for the informative video. it was also my first look inside a drum brake and it's good to see that they are in perfect condition. i'm curious to see how long the front brake discs and the rear drum brakes will last on my id.4 gtx.
3:09 In the Skoda Enyaq, you can stop, put the car back in N, then a message appears at the top of the screen asking you if want to keep the car in N. If you press that, you can work on the car as long as you keep the "ignition" on. Should be the same with the ID3 since the cars are quite similar 🤔
th-cam.com/video/YrwvuAamO-U/w-d-xo.htmlsi=xUQ0sVATassqBx82 Here is an example of someone doing it in an ID3 ;)
In my e-208, I found that when I shift to N, the regen is completely off even when pressing the brake pedal. I use it to clean the brake rotors from time to time, especially after driving in wet or snowy conditions. I pick up some speed, shift to N and brake semi-hard.
Also the parking brake toggle when pulled acts as an emergency brake, braking with the rear brakes only. Those need cleaning a bit more, the parking brake can otherwise get a bit sticky due to rusting and release with a loud clunk when driving off. I tend not to apply the parking brake when a risk of that is elevated (like after a rainy drive) when parked on a level surface, the motor P lock is enough. Oh, I'd love to have rear drum brakes! Makes even more sense on a RWD car where regen is on the rear, but the front gets used at least a bit.
The Drum brake in my (non-electrical) Audi A2 worked 13 years and 150000 km without any problem.
that neutral thing usually can be overridden by engaging the seatbelt in many cars.
A proper garage simply uses the programmer to put the car into brake maintenance mode.
couldn't you use the accelerator and the brakes at the same time for a couple hundred metres every week? that'd keep the discs shiny. this seems to me like a software problem. they could even schedule a brakes maintenance mode that does this automagically
I've tried that on my Cupra and it doesn't work, if you press brake it automatically starts regen with the electric motor. But if I put the gear in neutral no regen is applied when braking.
yeah i thought that would be the case with these things@@mkmproductions9257
They're a perfect choice on EVs for the rear axle where you anyway (in any vehicle type) need only a lot less braking power than on the front axle. Replacement is also cheaper, and often you can get away with just replacing the shoes/springs and not the drum. The issue with drum brakes is bad heat dissipation (again, not too much of a problem on the rear axle) which can in extreme cases lead to a lockup of the brake (also contamination of the shoes or a defective cyclinder might trigger that).
About those rear drum brakes on the ID3 it is best to have the single piston, so the shoe can either hold the car from running forward or hold on a hill from running back. When it is two leading shoes they are powerful in going forward but much less back. I wish manufacturers would use some other disc material. Maybe a version of Carbon, so they don't rust. Best Dave
Bjorn, thanks for this! Two tips… first, you can get the ID. Cars to stay in Neutral by shifting them to Neutral, then agreeing to a message on the center screen (aka Car Wash mode). And second, there’s no need to drive fast and brake hard - the easiest way to clean the brakes is just drive a low speed, shift to Neutral, and step on the brakes gently… especially going down a hill. In Neutral, regen is disabled.
Hi Bjorn I was looking at few days ago in my part’s catalog for a 2023 Canadian spec iD4 for rear brake parts prices and the hydraulic wheel cylinder are $ 30.00 each the drums are $ 70.00 each and the brake shoes are $ 120.00 for the set I remember when doing rear brakes on older VW that was driving on mix toads the shoes would last 200 000 km what I like is the Parking cables are not uses anymore they are motor that actuates the rear drums all the price that I mentioned is in Canadian currency. The only downside to drums is if the drums are too worn the brake pedal will be lower.
I have a Cupra Born and I put the gear in N sometimes to remove the rust from the disc brakes. Then there is no regen and only normal brakes are used.
I guess this works on all cars on the MEB platform, I don't know if it works on other brands though.
German but what a shit, from the beginning I have problems with the electric handbrake in my ID3 1st, it stucks/blocks almost everyday in wet conditions (Im Basque not German so u can imagine that weather in those terms its worst in the design country that in mine), When u release it putting the gear selector on D or R its blocked and you have to force it to run , I reported to my VW dealer like 5 times in those years till the handbrake finally as broken and the car was stopped for his security. 4 months in the garage cause the rear brakes handbrake was broken and were not spare parts for it, 4 months !! After that period they changed the servo and the actuator but not the drum pads which is the part that has contact with drums, so clever Vw!! So the problem continued as before, I reported but they never answered, you don't need to be a German engineer to guess that if the pads are bonded to the drums every wet day maybe the pads are the problem? I tell them to change the pads that I payed and problem its solved. Thats is not an electric car issue, its a general car issue. This was my 5th VW/Audi and the last.
Small cars with rear discs often rust their rear discs more than larger cars as they aren't heavy enough to get adequate load to clean surface rust thoroughly during braking, especially if the car isn't in regular use. Bias valves and ABS will be preventing brake lock up on a light car under hard braking. I use the cable operated handbrake a bit during driving to clean my rear discs of surface rust if I leave either of my cars unused for a while, one of which is fairly small and light the other not as small and light but it's use is less. This seems to do the trick for me. Neither are EV's but the principle is there for rear disc equipped cars regardless.
I have just replaced the discs and pads on my 2013 nissan leaf i have had the car for about 8 years and never looked at the front brakes
I think the best way to take care.of brakes is from time to time do a friction only braking: coast, switch to neutral and do normal braking without regen (it won't work on neutral)
Or, you have a car that uses the rain sensor to predict moisture on the brake and applies them with minimal contact to dry and clean them. The customer should not be required to do strange driving in public.
Did you mean to write neutral twice?
@@AlbertLamarque even ignore the sensor and from time to time reduce regen and do friction braking instead. Can be done with car's software. Probably will be a standard in future.
@@ArturFlies however the solution looks like, I agree. My "old" 2017 BMW i3 had a rust problem, my 2021 i3s does not. Something must have changed.
Modern EV's does this automatically
Actually, Renault Zoe has now brake disks on the rear, on the new model. The Zoe in the video is the old model!
Looks just like the one in my T2 bus.
Which is a good thing I guess, since it's still in pretty good shape after 50 years. :)
I know this is a different subject but I had to replace all my pads and discs on my three year old Arteon after only 16k miles, and I'm an older, steady driver. Discs were in an appealing state.
"appalling" ... definitely not "appealing"!
Brakes need to be used fairly hard frequently to not just rot away, if all you’re really doing is putting about town mostly engine/rolling resistance braking then the brakes will rot for the same reason EVs do.
@@MrAdopadoDon't be surprised if Google is spelling for you! Sometimes it's "interesting" to know which letters are close to each other on the keyboard. I press 5 instead of t "many" times on my pad...
@@leiflillandt1488 Yep, don't I know it! In this instance it was a fantastic typo example because it described the exact opposite of what was intended!
Most braking power is done by the front so rear not so critical.
Especially with an EV that regens a lot, so the physical brakes are used much less than with (non-hybrid) ICE cars.
That's why rear disc brakes rust on EVs.
And in a rwd ev like the id3 the regen is going to be at the rear.
I wonder then if fwd EVs have more regen potential than rwd EVs.
@@Tom-bp6noYes FWD and also AWD have better regen potential than RWD.
👍🏼👍🏼 I wish ly GTE would also have drum breaks. I had to get new disks for front and rear because they were so rusty since I used to drive 90% in B gear, now once a week I put the car into neutral and do a hard breaking from 80-100 to 0 since then it uses the disks, no regen to ”clean” the disks
It can be much more economical to have no regen and just roll, and then brake. Regeneration has its losses as well. Harder regen have more heat loss.
Obviously if driving down a long hill you'd use regen to keep from speeding, much like low gear to brake via engine on old ICE cars.
You can drive a long way for the price of new brake disks. So even if it sounds less economical to not regen it might not be in the long run.
@@Gazer75I thought the current set of EVs were adopting a profile of explicitly working the disk brakes from time to time; will have to check. Otherwise, yes, some manual intervention is required. A bit like on every cycle ride on a bike with hydraulic disk brakes I need to pump the brake levers whenever I set off to force any air bubbles up from the piston into the reservoir in the brakes. Just another habit to adopt
I had the same on my GTE, factory brakes lasted 3 years. However I got some good quality low corrosion replacements and they lasted 5 years with no obvious sign of wear.
If you use D or B doesn't really make a difference in the GTE. Yes, it doesn't regen when you take your foot of the accelerator, but once you step on the brake it will do max regen possible before engaging the brakes.
It actually has a brake cleaning mode. After accelerating and braking hard twice, it will no longer engage regen for a little while. This allows you to clean the discs much easier, but the rear discs are still an issue.
I bought my GTE with 3 years/20,000km, and it needed new rear brakes immediately. Tried cleaning them, but the corrosion was too severe, they never cleaned up.
The front tires kick up all sorts of spray and crap. That is why drums in the back are better for regular passenger cars. For maniac driving you might want discs.
I find drum brakes to be pretty good. They need to be set up correctly to work properly, so more finicky than disc brakes. The best advantage though is that drum brakes has zero drag. That they overheat easier is not really a problem for most people unless you drive on a race track or drive down a mountain and use the brakes instead of engine braking…
Harder to engine brake on an automatic or EV, but I've found cruise control to work well when doing big mountains to set that steady rate for the straight parts. This also stops my car having the "tourist lights" on as my Munich-based friends to use to describe brake lights on vehicles from north Germany doing alpine roads with the brakes on all the way....
The surface rust on the outside of drums is just cosmetic - my VW UP came painted grey and a coat of wax prolonged the life. Easy to respray or coat with rust protector too because no risk of contaminating the enclosed brake surface or friction material
Something I really don't like with many european cars is that they often have wheels mounted with bolts instead of nuts you screw on threads that makes shifting wheels so much easier, especially with thick aluminum wheels.
Try use screw driver as a guide pin. It is still painful. But not as much like you dont use nothing
I'd expect the threats to get damaged quickly when someone who struggles with the weight of a wheel pushes it along the threaded rods.
the best for rust (and cost..) would be to have just one one drum brake enclosed at the center of the car👌
And good luck pedestrians at crosswalks!!🤣
It would be interesting to see how drums on the front and rear with regen compared in normal driving to disc/drum and also emergency stop
I don't have an issue with the drum brakes on our Born. One benefit that often gets overlooked is that the brake particulate is confined inside the drum and so less likely to enter the environment. Not the case with discs.
What do you think happens, when a mechanic will work on drum brakes? I give you a hint, compressed air will be involved....
@@Chris675R Thanks for stating the obvious. My point was, (which seems to have passed you by) is that removing the dust and particulates in the workshop will reduce the likelihood of it being dispersed around the environment and ending up in the places it shouldn't be as the car travels around.
@@MartynDews Well, where do you think the mechanic will go, if he will clean out all the dust with the compressed air? He will certainly not do it in the shop, so all the people in there have to breathe in that healthy dust. He will go outside or at least hold it out of the window and release it into the air.
In theory you are right, while braking on the road, the drum brakes contain the brake dust, but it will be released into the air anyways, if the brakes are being serviced.
@@Chris675R Not being as familiar with the internal operations of a workshop and the mechanics within, I'll have to take your word for it.
@@Chris675R Good way to get miners lung, mechanics here use a vacuum cleaner with a HEPA filter.
Drum brakes are as good as disc brakes in their ability to turn motion into heat. Their biggest problem was to disperse the heat, because heating expands the drum, and the brake shoes run out of travel trying to chase the receding drum's surface. Another difficulty is the brake shoe itself, which can also overheat and 'glaze' the braking surface. This is a chemical transition that decreases the friction (turns it into a form of glass), which also diminishes the effectiveness. Both situations can be designed out, but with simple disc brakes, isn't worth the effort. They are, however' very inexpensive to manufacture, as well as very reliable. Since very little braking is done by rear brakes (because the centre of gravity moves forward under braking), they are never overloaded. The rear brakes also are the most convenient to use as parking/emergency brakes. The design used on the ID3 gives equal braking both forward and backwards, as well as a self-adjustment mechanism. The central groove is another feature with two benefits. The first is to provide shorter routes from brake dust created by wear, to get out from between the shoes and the drums in normal use (infrequent heavy braking by the rear brakes). The second reduces the friction surface and thus enables a harder braking compound to be employed, while not reducing the effectiveness of the design in the process. This gives a longer service life to the rear brakes, which might match the life of the front discs as far as servicing goes. I understand that VW has been experimenting/employing a slip-seal around the edge of the drum and back-plate to exclude the opportunity for water and debris to enter the mechanism, but, self evidently, this seems unnecessary if you consider this car's experience.
Nice video. There is nothing wrong with rear drum brakes in an average vehicle. Four wheel disk is just a salesman's talking point.
How about difference in braking force between left and right rear drumbrakes? Mine was almost out of spec being at the TÜV inspection after 3 years (45000km)....
Even on my Golf IV, I had trouble getting the rear brakes to pass more than two semi-annual MOTs/EU controls in a row. Rusty brake discs was always a problem, and on an EV the problem would be even worse. So I'm very happy my ID.4 has drums in the rear - they're just a lot more hassle free.
Imagine paying at least 40k € for an ID4 and just getting rear drum brakes 😂
@@philipp5183 You didn't get the message in this video or in what I wrote at all, did you? Drum brakes on the rear is the better solution because discs are complete overkill. It's got oodles of regenerative braking on the rear. Rear discs would just sieze and rust.
My fist car, a VW Golf MK2, had drum brakes in the back as well. :)
Only problem with drum brakes on old cars that had them would be failed hydraulic seals. These would allow hydraulic fluid to leak on to the brake linings. Not a pleasant job on old cars with asbestos dust that you had to remove from the drum ... or black sludge if it was mixed with hydraulic fluid! In principle it seems a reasonable choice of braking system for the rear on an EV.
Also the self-adjusters either rust solid, or get jammed up with brake dust and stop working, so as the pads wear they aren't compensated.
Break size is determined by car mass for homologation, so heavy EV cars will have unusually big brakes. To prevent EV disk brakes from rusting, make harder breaking from time to time especially in wet conditions, or the best the next day after car wash or rain. It will clean the rust and prolong disk lifetime. Drum brakes are better sealed, not exposed to water so much, so this is one of the reason they are used for EVs.
What i would have done is give the drums a clean with brake cleaner , Also on contact surfaces that have corrosion sand them down with a wire brush and apply a generous amount of copper slip grease .
Then that would be sorted 😀
Drum brakes - that's called cost cutting :)
Not really. Discs on the rear are not needed
It is cost cutting, but not in the way you think - the cost cutting is for the owner mostly. This is because the rear brakes are almost never used, only in full emergency. The ID3 has the electric motor in the rear. When you are braking even quite hard, then first the friction brakes apply in the front, because that is where the majority of the braking force comes from. The front does about 70-80% of the braking, and the rear only has to do 20-30%. In most cases the electric motor is enough to provide this amount of braking in the rear and the rear brakes do nothing.
If they fitted standard disc brakes they would either need to install really expensive special rotors that do not rust easily, which would drive up the price of the car, or if they fitted standard parts you would have to replace them every year, since they'd get completely rusted, as they are never used.
If the electric motor was in the front, then they would have fitted disc brakes in the rear.
Tesla for example does not have this "problem" because Tesla still can't do brake blending even today. So every time you touch the brake pedal both the front and rear brakes are physically engaged. This is not the case on the ID3, where in the beginning of travel the brake pedal only engages the electric motor, and not the friction brakes, then the front brakes are phased in and in the very very end if absolutely necessary (near full emergency stop) come in the rear friction brakes.
On our 2017 Chevy Bolt EV, we found out the hard way, to put the car in neutral once a day or two - and use the friction brakes only - to clear the rust.
Rear drum brakes, excellent idea, they are just as good as disk because disk system in the back often get jammed with salt on the roads.
Unless you do track driving, no passanger car needs disk brakes for rear for speeds that most countries allow. Rear wheels do not have enough traction to warrant disk brakes for the brake power but drum brakes are slow to release heat so if you do multiple heavy braking actions in series, the drum brakes may overheat and brake shoes no longer work well.
You guys forgot to mention most breaking force is on the front, as car leans forward when you brake. That means drums pretty ok for non track use.
@11:20 Best thing you can do is to have no regen if not driving long down hills and actually use the brakes. Yes some, if not most, EVs will regen with light braking, but if you press harder they do apply friction brakes. Dealers often recommend to brake hard once a week during winter, especially if its raining and not much salt is on the road.
Even in summer if its raining a lot it can be a good idea to brake hard every so often to avoid rust buildup.
I always drive with no regen and brake harder every so often during the salt season to make sure brake pads don't rust.
Excellent video and a very good farewell
Is the cost of labour in Norway so high that turning the used discs would be more expensive than replacing them?
Those are quite sizeable rear drum brakes.
Hello from Germany, I am questioning myself why you have brakes at all in Norway? Being there 2020 with our Pickup Camper we only met obstacles on the roads, driving so slow and with all the bumps and speed limits everywhere, no need to brake, most times I used the indicator to pass you 😂
If you like driving stay away from Norway. Crazy speed limits everywhere. You Can end up in jail if you exceed the limits.
Same could be said for Germany, road works 365 days a year. For a country know for being efficient you guys do take a lot of time on roadworks...
It was one of my many reasons for getting rid of the Kia Niro EV. I braked hard 3-4 times on my way home from work, drove a bit past my house and reversed at max speed slamming the brakes while using the "clean brake discs" mode, and even then my rear discs were rusty. Crap quality, but why not just put a drum brake in there. Even with the Picanto/I10, they had rear discs. Completely unnecessary.
Drum rear brakes are safer because disc have a tendency to cool and contract after driving, this can release the hand brake.
That's a good point, but I think EVs also lock the transmission when the parking brake is applied. Never heard of an issue with Teslas slipping their parking brakes?
I thought I was alone to prefer drum brakes for their rustproof qualities. I have to replace discs every 3 years on both my Saturns that's why I hate disc brakes. Semi trucks use drum brakes on all wheels in North America. Big truck companies have resisted the change to disc brakes because of their higher maintenance cost. They understand this consumer trap.
Heavy trucks in Europe and now most Semi Trailers have moved to Disc Brakes, Unusual to see anything still running drums these days.
@@-DC- Europe is a nightmare of over-regulation. That's what happen when women take control of politics.
Should be possible to add some system to collect the break dust -> would be even better
Brake shoes can provide more braking effort than brake pads and discs, the only real disadvantage with shoes and drums is that brake dust builds up and because they are enclosed they don’t dissipate heat as well as discs.
I have never seen drum brakes this big on a small car. These probably have more braking force than same diameter discs because of the larger contact area between the shoes and drum compared to a single caliper. Also the entire friction area is farther out than a disc, which relies on friction at a shorter radius from the center. Hand brake actuation is probably also easier to integrate into drum brakes. The downside is the wear parts are hidden from visual inspection and they have reduced cooling comparead to discs, but cooling is not an issue on electric cars.
Interesting to hear how many countries use salt on the road. I thought it was just UK
I can't remember exactly who said it when, but one of the engineers at Tesla said that they use a custom material for their brake discs which is more corrosion resistant. Can confirm as a Tesla owner, apart from a tiny bit of surface rust after a rainy day, there is no serious corrosion on them. For a non-performance car, I think drums are a great Idea for EV's as you dont have to worry about corrosion at all. Also potentially saves money by having a mechanical handbrake using the rear drums
It'll also stay in neutral with the door open if you have the seatbelt fastened
the brakes are under ABS anyway, and the ABS can be programmed to make the brakes feel like however you want them to feel
so it can feel 'sporty' , but you cannot drive 'sporty' for very long because of the heat buildup
In my opinion, VW hasn't made a bad decision here - at least for the smaller and weaker models, completely sufficient, since the recuperation takes place on the rear axle anyway and can also be better regulated.
However, I see practical problems with the large, heavy models:
The trailer load is therefore much lower. The ID series only has around 1200 kg for braked trailers. It's particularly bad with the ID Buzz, which has an empty weight of over 2400 kg but is only allowed to tow 1000 kg. Completely unusual if you compare it to a T6 and its 2500 kg.
I think the trailer load is limited by the motor cooling mostly, not brakes. Because those VW EVs are heavy they do not have sufficient cooling to add a lot of additional towed mass.
@@UhOhUmm EVs overall have bad towing capacity, my parents Subaru Solterra only has 750kg capacity meanwhile my E-tron does 1800kg which is decent enough but still quite a bit lower than what a Q7 3.0 TDI can tow(3500) for example. Even the Tesla X is quite limited at only 2250kg comparatively.
1:40 how did YOU not know that, bjørn? 😅
The shoes and hardware look excellent, esp for the climate there.
thanks for a great overview video with an exceptional sign-off!
drum brakes are cheaper to produce and lighter in total (that might surprise you), which is veeeery important in weighty EVs. This weight is why ID.3 with bigger battery has only 4 seats. Drumbrakes are less frequently to maintain but when you have to maintain them, this guy with hammer is going to charge you significantly more (changing a break pad is so easy ...). The trouble is ID.3 is not cheaper than TM3, so the savings do not go to customer's pocket.
oh no please open the electronic parking brake via the Diagnose port and set it in Service mode
Drum brakes tend to fade much quicker, but because you have regen on the rear axle and if you brake hard mostly the front brake is doing the job, so this is no problem. You are not driving on the race track where you have constant braking
They aren't just better for rust - calipers can stick/seize often in salted road conditions but in the drums they are mostly protected.
The I.D is a rear drive3 car so rear regen also. That means the brakes are large incase of emergency stops but most other times they are hardly used.
Disks are only better for heat dissipation but on most ev's thats never going to be a problem anyway since you can't push them hard enough for long enough to get the rears to cook anyway.
They are certainly a better choice for this application.
Don't mind the rear brakes being drums since regen should keep them from overheating, but I wish VW would use steel-lined Aluminum drums to drop unsprung weight.
Die Aluminium Trommeln beim Lupo 3l oder Audi 3l waren eine Katastrophe, ich habe viele wieder auf Stahl umgerüstet 😂
@@retiredbore378 You mean galvanic corrosion, which is preventable. From what I can find of weights, it seems like drums are ~15lb/corner. Saving even 20%, so 3lbs/corner unsprung, is huge. Granted, OEMs don't seem to agree, judging by the stock disc brake parts and wheels they spec.
@@retiredbore378 Galvanic is a different type of corrosion requiring an applied voltage, not just a different name. As for the unsprung weight, I'd expect it to be 75-100lb/corner. I don't know about the hub/knuckle in particular.
I have a question
2 years ago I took My ID3 to workshop for first service
They said no need to replace break pads /shoes
Now it almost 3 years with 40,000 km range
Do I need to be worry about my break pads wearing?
Because my first EU control is around 7-8 months next
Because some days in the mornings the breaks was locked and I car moved very hardly
Drums are removed because they heat up, and dont brake so good. Takes long time to cooldown. But on EV no track usage, so no issue!
Ah thanks I was looking to se if someone had written about possible negatives of drum brakes. I'm guessing they are a little bit more expensive in production as well?
Good video
Very informative and serious
Drum brakes read 💪💪💪
Great video and more double acts please!
Tesla needs the caliper slide pins cleaned, polished and greased. This allows the pads on both sides of the disc to retract.
That is what normal car needs too, the slide pins cost like $1 for normal cars, so better replace them. The worst part here is we use salt on the roads, so lots of rust everywhere. And the pads can get stuck where they are supposed to glide.. making only one of the pads engage when braking.
@@AndrewTSq I have the same salt usage in Michigan. This summer I pulled my calipers and polished and greased the pins. I didn't check how much new pins would cost plus the drive to the Service Center. They'd need to come out either way.
@@eb1888. I do it once a year with my old Volvo, never had a caliper seize. Quick job when you are changing the tires. Unbolt the pins and run them on the wire brush, lubricate and remount.
Never had as little problem with brakes on any of my old cars, as i had with those that had drum brakes. They just don't rust the way disc brakes do.
When will you review a model 3 highland?
Alternative routes and speed cameras are probably the best part of this update, blindspot indicator light is not bad but the way tesla does blindspot detection isn't very good, even for the new highland, 1 day they'll make something good/innovative for blindspot detection, I hope.
What would have been nice is the fabled tesla app store that was rumored awhile back. Plus maybe in the not too far future Tesla will redesign the voice commands into a voice assistant (Alexa but orders of magnitude better) which can function the car and help you with anything like banking, groceries, questions etc..
For the id3 you can drive slow, set the car to neutral. Then the brakes are used. In D or B the recuperation is used first. Be careful anyway.
I always do that while driving fast in my GTE. 🤔
any car is like that
My id3 uses front and rear brakes on the first breaking of the drive. And also when you recharge to 100% it can’t regen and uses both brakes.
@@testi2025 It hink that is not the whole truth. The mechanical brakes are used, when the electrical brakes are not strong enough- If you are a defensive driver (like me) i expect nearly no usage of physical brakes. If the battery is fill (100%) or the car is in neutral, than you are right-
@@ndc5544p Probably. From my point of view, it is a question of strategy. So maybe, there are differences from Car to car. Even the much heavier cars like ID4 might be different to the ID3.
That disc brake at 0:58 is totally fine! Thats nothing!
drum brakes are perfect for cold climates like Norway has... Here in greece where we have hot climate when they get hot they underperform because they have poor ventilation in compare to disk brakes ....
Did your ID3 in Greece have problems?
@@bjornnyland I don't own an electric car.. I have a car which has drum brakes in the back wheels and in the summer in long and steep downhills they have problems overheating and don't brake properly..
I have had drum brakes in warm, sunny California look much worse after many years. VW used very good quality parts here, yes!
Why not have a sacrificial metal (anod is it?) on the cars that run in countries that salt the roads or in citys by the sea? Like you do on metal parts on boats.
In Europe it's always the rear disc breaks that is rusty... Not the front.
This is Euro7. Brake dust on servis room not in air