Just wanted to say thank you for posting this. I have some hydraulic cylinders that need work and this motivated me to do it myself instead of sending them off for rebuilds.
I agree, about the only difference in hydraulic cylinders is how they are held together. This trencher has been re-born and is currently available trough Northern Tools ( with some updates). It is the same price as the Harbor Freight, although shipping is cheaper at HF. I do think this one is a little better built.
So these seals, listed below in your reply, WILL fit the Harbor Freight 9 hp excavator? Or is HF a different size? I was wondering if these seals should be applied wet with oil rather than dry.
I had to call Energy Manufacturing at 319-465-3537. They did not have these parts available in their on line store. I was able to cross the parts- Rod Seal DRO-1250X1625X0312U3000. Wiper MCN-1251 , Large O-Rings OR-232N6001(x2) , small O-ring OR-020N6001, Piston Seal HPX-334-2H2155. All part number should be available at any hydraulic shop (online or physical)
Thank you for the video! I just got a Harbor Freight trencher and the main Boom cylinder is leaking from the seal road I changed with a new one that came with it but still leaking. The seal for some reason pop out just a litter bit enough to leak . There is anything that you may think cause this? Does surplus sale those type of seal? Thank you so much for sharing your knowledge .
That's a hard question to answer. I am not familiar with the harbor freight cylinders, but they appear to be threaded cap instead of tie-rods. The seal replacements should be similar, other than the way they are held together. Was there any damage to the oil seal or wiper that you replaced? Any chance you damaged the oil seal on the threads of the rod when you re-assembles the cylinder? Are there any burrs or scratches on the rod? Is the rob out of round? For replacements seals, I would recommend crossing the seal through Hercules Hydraulics. I don't think Surplus City carries individual seals, except for their house brands.
@@MuddFlappRanch thanks for the fast replay, the rod is good I just found out that one of the o ring was missing not install by the supplier. The unit came with some extras o ring and I just installed and works fine. The reason I was able to find that was because I saw your video and you explain how to repair the cylinder. Thank you again!!
I like the way you explain this very simple ha ha I like simple because iam Not the kind of guy that can read a book On how to do this type of thing kind
@@rooseveltthingsmakers what are you using the cylinder for? Also the force on a cylinder varies with the hydraulic pressure. The sick cylinders on this machine are 3 inch (76.2mm) in diameter and the pressure is 2000 PSI ( 140 bar).
@@MuddFlappRanch first of all, i'd like thanks to your atentions of my questions. So, i going to make a machine like yours, here im Brasil is very difficult find especific these parts, so your cooperations is very important for me. the hydraulic cylinder that im gound to use is 3" it suport 200 bar and a pump is 4 cc.
Great video.. I'm currently in the middle of building a towable trencher. Right now i'm just building the frame. I'm not really knowledgeable with alot of hydraulics. Once I get my tank, engine/pump, valve manifold, rams and hoses installed. How is the best way to bleed the air from the dry system? I was hoping that you might give me some tips. Also, I'm on a toss up of what pump to buy. I've read that it's best to use a single stage pump with 2 - 5 gpm. But the local hydraulic shop told me that I could use a 2 stage log splitter pump that is 11 gpm... Which is 9 gpm on the first stage 650psi, and the second stage is 2gpm at 2500psi.... I'm rather confused....
Thanks for watching and for the kind words. I don't have experience with running a 2 stage pump on this machine, but have considered it. Some of the issue I see with the 2 stage pump are making sure that your valve can handle the flow and the the shift pressure of the two stage pump. A gear pump makes constant flow, in your case 9 GPM (until you hit 650 psi), anytime the motor is running. If you are not activating the valve, this 9 gpm flows across the open center and back to the tank. Many of the affordable 4 spool valves are rated at or near this flow rate, meaning more restriction and increased heat in your oil. The second issue is how much pressure is need to move the bucket or lift the boom. If you exceed 650 psi, it will kick into HI mode and I can see issue with the pump oscillating between HI/LO modes. The trip point is usually adjustable to a degree. Also the ~3gpm pumps that come on these machines is extremely slow and pretty much makes operating 2 cylinder simultaneously impossible. The flip side is too much flow and the cylinders move too fast to be reasonably controlled. Flow restrictors are an option to consider, but that adds to the cost and the heat in your oil. Hydraulics is all about trade offs, larger bores equal more force, but slower operation and vice versa. The trick is finding that sweet spot.
Thank you for the informative video. I have a Yard Pro MB-300 towable back hoe needing a ram rebuild. Was wondering where you sourced the rebuild kit. Can you recommend a source for the parts or the kit? Thanks
The easiest option would be to reach out to Jansen USA ((619) 955-3860) and see if they offer a rebuild kit for your machine. If they don't, or it is overly expensive you will need to disassemble the cylinder and measure your piston and the oil seal sizes. Once you know what size seals you need need, there are several online retailers that can help. It will also help if you can find a manufacturer or part number on the actual cylinder, as Jansen is likely just buying these to put on the machines.
Thanks for the fast reply. I bought a DR version in 2018. And I am always looking for things people are doing with these small backhoes. And got a bonus with your video of repairing a cylinder. My tractors three point lift is bouncing and I think the cylinder for it is sort of like what you just did. Anyway thank you for the video.
I had to call Energy Manufacturing at 319-465-3537. They did not have these parts available in their on line store. I was able to cross the parts- Rod Seal DRO-1250X1625X0312U3000. Wiper MCN-1251 , Large O-Rings OR-232N6001(x2) , small O-ring OR-020N6001, Piston Seal HPX-334-2H2155. All part number should be available at any hydraulic shop (online or physical)
Just wanted to say thank you for posting this. I have some hydraulic cylinders that need work and this motivated me to do it myself instead of sending them off for rebuilds.
Glad I could help
thank you for the education,
Thanks for watching and commenting!
Thank you for sharing your knowledge. I like your style.
Thanks for watching! And thank you very much for the compliment.
Great job 👍🏻 👏 👍🏻 👏
Thanks for watching and for commenting.
Same basic steps any hydraulic cylinder.
While his trencher resembles the Harbor Freight one available today, it is built better.
I agree, about the only difference in hydraulic cylinders is how they are held together. This trencher has been re-born and is currently available trough Northern Tools ( with some updates). It is the same price as the Harbor Freight, although shipping is cheaper at HF. I do think this one is a little better built.
So these seals, listed below in your reply, WILL fit the Harbor Freight 9 hp excavator? Or is HF a different size? I was wondering if these seals should be applied wet with oil rather than dry.
I am not certain about the HF trencher, but the seals are usually pretty specific. I would recommend lubricant for the install.
Where can I buy that seal kit? I have a trencher like yours.
I had to call Energy Manufacturing at 319-465-3537. They did not have these parts available in their on line store. I was able to cross the parts- Rod Seal DRO-1250X1625X0312U3000. Wiper MCN-1251 , Large O-Rings OR-232N6001(x2) , small O-ring OR-020N6001, Piston Seal HPX-334-2H2155. All part number should be available at any hydraulic shop (online or physical)
@@MuddFlappRanch thanks 😊
Very informative and great video. Thanks for sharing.
Thanks for watching.
Thank you for the video! I just got a Harbor Freight trencher and the main Boom cylinder is leaking from the seal road I changed with a new one that came with it but still leaking. The seal for some reason pop out just a litter bit enough to leak . There is anything that you may think cause this? Does surplus sale those type of seal? Thank you so much for sharing your knowledge .
That's a hard question to answer. I am not familiar with the harbor freight cylinders, but they appear to be threaded cap instead of tie-rods. The seal replacements should be similar, other than the way they are held together. Was there any damage to the oil seal or wiper that you replaced? Any chance you damaged the oil seal on the threads of the rod when you re-assembles the cylinder? Are there any burrs or scratches on the rod? Is the rob out of round? For replacements seals, I would recommend crossing the seal through Hercules Hydraulics. I don't think Surplus City carries individual seals, except for their house brands.
@@MuddFlappRanch thanks for the fast replay, the rod is good I just found out that one of the o ring was missing not install by the supplier. The unit came with some extras o ring and I just installed and works fine. The reason I was able to find that was because I saw your video and you explain how to repair the cylinder. Thank you again!!
I like the way you explain this very simple ha ha I like simple because iam
Not the kind of guy that can read a book
On how to do this type of thing kind
Thanks for watching! Hope this helped you
Good video very informative thanks
Glad you enjoyed it
Hi friend, my name is Roosevelt i'm brasilian, can you say me how many tons suport this hydraulic cylinder? Thanks
14000 pound-force = 6.35 ton-force (metric)
@@MuddFlappRanch Thanks my friend, thanks a lot for the attention.
@@MuddFlappRanchcan i get little more of of your attention? if i use a hydraulic cylinder of 5 tons do you think its ok?
@@rooseveltthingsmakers what are you using the cylinder for? Also the force on a cylinder varies with the hydraulic pressure. The sick cylinders on this machine are 3 inch (76.2mm) in diameter and the pressure is 2000 PSI ( 140 bar).
@@MuddFlappRanch first of all, i'd like thanks to your atentions of my questions. So, i going to make a machine like yours, here im Brasil is very difficult find especific these parts, so your cooperations is very important for me. the hydraulic cylinder that im gound to use is 3" it suport 200 bar and a pump is 4 cc.
Great video.. I'm currently in the middle of building a towable trencher. Right now i'm just building the frame.
I'm not really knowledgeable with alot of hydraulics. Once I get my tank, engine/pump, valve manifold, rams and hoses installed. How is the best way to bleed the air from the dry system? I was hoping that you might give me some tips.
Also, I'm on a toss up of what pump to buy. I've read that it's best to use a single stage pump with 2 - 5 gpm.
But the local hydraulic shop told me that I could use a 2 stage log splitter pump that is 11 gpm... Which is 9 gpm on the first stage 650psi, and the second stage is 2gpm at 2500psi....
I'm rather confused....
Thanks for watching and for the kind words. I don't have experience with running a 2 stage pump on this machine, but have considered it. Some of the issue I see with the 2 stage pump are making sure that your valve can handle the flow and the the shift pressure of the two stage pump. A gear pump makes constant flow, in your case 9 GPM (until you hit 650 psi), anytime the motor is running. If you are not activating the valve, this 9 gpm flows across the open center and back to the tank. Many of the affordable 4 spool valves are rated at or near this flow rate, meaning more restriction and increased heat in your oil. The second issue is how much pressure is need to move the bucket or lift the boom. If you exceed 650 psi, it will kick into HI mode and I can see issue with the pump oscillating between HI/LO modes. The trip point is usually adjustable to a degree. Also the ~3gpm pumps that come on these machines is extremely slow and pretty much makes operating 2 cylinder simultaneously impossible. The flip side is too much flow and the cylinders move too fast to be reasonably controlled. Flow restrictors are an option to consider, but that adds to the cost and the heat in your oil. Hydraulics is all about trade offs, larger bores equal more force, but slower operation and vice versa. The trick is finding that sweet spot.
Thank you for the informative video. I have a Yard Pro MB-300 towable back hoe needing a ram rebuild. Was wondering where you sourced the rebuild kit. Can you recommend a source for the parts or the kit? Thanks
The easiest option would be to reach out to Jansen USA ((619) 955-3860) and see if they offer a rebuild kit for your machine. If they don't, or it is overly expensive you will need to disassemble the cylinder and measure your piston and the oil seal sizes. Once you know what size seals you need need, there are several online retailers that can help. It will also help if you can find a manufacturer or part number on the actual cylinder, as Jansen is likely just buying these to put on the machines.
why did you undo the hoses last after loosening the 4 rods. And thanks for the video. I subscribed because of this video.
no particular reason for the order.
Thanks for the fast reply. I bought a DR version in 2018. And I am always looking for things people are doing with these small backhoes. And got a bonus with your video of repairing a cylinder. My tractors three point lift is bouncing and I think the cylinder for it is sort of like what you just did. Anyway thank you for the video.
Have difficulty locating the parts. Can you provide the source and part number of the kit, please?
I had to call Energy Manufacturing at 319-465-3537. They did not have these parts available in their on line store. I was able to cross the parts- Rod Seal DRO-1250X1625X0312U3000. Wiper MCN-1251 , Large O-Rings OR-232N6001(x2) , small O-ring OR-020N6001, Piston Seal HPX-334-2H2155. All part number should be available at any hydraulic shop (online or physical)
@@MuddFlappRanch Great & thank you.
I just did mine. Call Energy. Give them the number cast in to the cylinder ends. Kit #21987X was what I needed.