Just got one of these used. Find the manual online. I just spent a few hours trying to fix mine and everything you need to know is in the free manual. Mine working great now. The primer plastic knob is held on by two very small Allen keys, one on either side of the knob (that's not in the manual)
Hey Gringo, did you get the 505 pumping? I have a Wagner 848 which is quite similar to what you are working on. One BIG problem you have is with old dried paint. It should be spotless inside. Start at the inlet valve and clean it! Get every speck of paint out of it. Then hold it with the open side up and fill it with water. It should hold water with nothing leaking out. With it full of water, put something like a pencil inside and push the valve open. The water should drain out. If it doesn't hold water, maybe you need a new inlet valve. Then take the head off again so you can see the diaphragm . Clean out every bit of old paint inside the paint chamber. The plastic disc inside is removable also. Take it out and clean all paint from there and replace the disc making sure you get it back in facing the same way it came apart. While you have it apart, you might as will replace the diaphragm. Next to the inlet valve is a hex plug. The outlet valve is under the plug. By the way your machine looks, you will probably find paint in there too. Under the plug you will find a spring and ball. The ball sits on the seat. Remove the seat with an allen wrench and replace it with a new one along with the ball and spring. On the side of the head is the recycling hose and the supply hose. The recycling hose slips onto the brass nipple with the other end going into the paint bucket. The supply hose screws onto the threaded nipple. Put your gun on the other end. The spray / prime knob that was loose is held on with two small allen srews . One on each side of the knob. After you have it all back together, put the machine on it's back so the inlet valve is pointing up and squirt a bunch of wd-40 into it and once again, push a pencil against the valve and let the wd40 go inside. Put the suction tube back onto the inlet valve, get it tight and upright the machine with the suction tube in a bucket of water. Be sure the spray / prime knob is on the prime side and the pressure switch is on the lowest setting. Fire up the machine and let it run for a little while. I usually need to turn the pressure knob up about half way or higher. It should prime itself after it runs for a while. When it finally gets primed, you should see water coming out the recycle tube. If it doesn't prime itself, don't bother trying to spray anything, it won't work if it isn't primed . After it primes itself, turn the pressure down to minimum. Whenever you change from spray to prime, or from prime to spray, be sure the pressure is adjusted to the minimum setting. After it is primed, switch it to spray and try spraying some water through it. You will need to increase the pressure, but it should work. Look online for the instruction manual, if you haven't already done so, it's available. Let me know how you're coming along with it.
Thanks for the info I haven’t been online in a while and I ended up selling this rig to a buddy of mine but I wish I would have read all this before I sold it.
The reason that you cannot get it to prime is probably due to the output valve being stuck. The little ball inside the valve is spring loaded and if the paint is allowed to build up inside, it sticks - and when I say it sticks, I mean it sort of glues itself to the seat of the valve and is very hard to get it loose. The prime 'switch' just has a set screw or two that have been opened so that they don't hold the knob in place. The prime switch is just a needle valve that is pulled open so that the output pressure is bypassed to the paint can. When the knob is turned to 'spray', the needle is closed so that the appropriated pressure is applied to the pressure hose and the gun. Consider what you are willing to spend on this unit. I have a 400 which is very similar. I used it for several years - once in awhile, but it worked every time I tried it. Always it was hard to prime. Finally after a few years not using it, I had a situation where I thought I might need it, so I tried to get it to pump water. It did not want to but it finally did. It seemed to be operating so I put it to work on a fence using oil-based stain. I wasted a half gallon of $45 stain trying to get the thing to pump and spray. It would circulate into the can, but when I wanted it to spray, it plugged up. So back to the shop, cleaned everything out and ready to go again after replacing the intake valve, the output valve and the diaphragm - to the tune of $129 - it should be ready to go. Cleaned out the filters and the gun etc. I went to test the unit, it would not prime! I opened the cover on the oil pump and discovered that the intake tube for the hydraulic pump was not only broken - it kinda disintegrated. So I found a piece of tubing to use in its place, refilled with oil and tried again, still did not prime. The hydraulic pump is not producing any pressure to actuate the diaphragm to produce pressure and intake vacuum for the paint portion of the system. The old parts did that, but now it doesn't. And I cannot figure out how that hydraulic pump is supposed to work. I took it completely apart and can find no check valves or moving parts of any kind in the hydraulic system. There is nothing that I can see that would cause the pump to circulate oil. There is no way to create a vacuum except possibly the piston moving down, but there is nothing to keep the oil that is above in the chamber from coming back out as the piston comes down, so I don't see how it can possible stop the flow to create a vacuum or build up pressure. There is a needle, but it is used to regulate the pressure that the system builds up if the pump actually pumps the oil. That needle regulates the opening for escape of the oil back into the reservoir and there is no check valve on it either. What is supposed to happen is that the piston goes up and compresses the oil in the chamber where the diaphragm is located. That pressure causes the diaphragm to pressurize what ever liquid is on the other side and if the ball check output valve operates, the pressurized liquid is pushed out through the output valve, through the bypass and back to the paint can. At the same time, the intake valve operates causing a vacuum on the input side of the paint system so that more paint is pulled by vacuum into the intake side to be pressurized by the diaphragm's actions. If the diaphragm can be moved, the paint system on my Wagner 400 works fine, but the diaphragm does not see any pressure from the hydraulic pump any more. As the diaphragm is actuated by the hydraulic pressure, it will build up the pressure rapidly on the output side so that when the trigger on the gun is actuated, the pressure will force the paint out through the nozzle onto the surface. But without hydraulic pressure it cannot build up the spray pressure. So the long and short of it is - if you decide to pay $130 for the kit to repair your 505, you might have thrown the money away because the hydraulic system is also bad or will fail shortly after you put it under pressure again. Like I said, I cannot figure out how the hydraulic pump works on this particular version of the Wagner hydraulic pump. I watched a video on a couple of other Wagner products one of which was very similar except the intake for the oil pump was in the piston itself. The repair video showed that the repairman was able to run the pump with the cover off and show that it was actually physically pumping the oil around. But on that one too, I could not see how the hydraulic pump operated. The piston had one hole in its side that I could see and no other way for oil to go in or out, yet that piston was supposed to be pumping the oil around? There had to be some form of check valves to cause the oil to stay once it was pumped and to create a vacuum when the piston went the opposite direction. This particular version had only the needle port to meter the oil when the pressure was too high, but I don't see how that pressure was developed. There has to be a check valve somewhere on the hydraulics side just as on the paint side. The paint side has a check valve on the intake and on the output. I suppose that the piston going into the cylinder would act as a check valve of sorts for the intake. And after the piston began to move up, the valve would be closed allowing the other end of the piston to cause pressurization, but without some kind of output check valve as there is on the paint side, I don't see how it works. For example, if there were a hole near the top If someone knows how these pumps work, I would appreciate a clue be given to me. LOL
I had a similar problem on my wagner 635. I replaced the diaphragm and hydraulic fluid but it would still not even attempt to prime. What I found out is that before you install the new diaphragm, you must fill that cavity in the pump block that it sets into with hydraulic fluid. After doing this my spray primed and built pressure no problem. Not sure if this is the same scenario that you are experiencing, but I hope it helps.
@@scrubjaycyan4373 Thanks, that is an interesting idea. I will give it a try. The only thing is (well not the only thing, but one thing) that I had replaced the diaphragm several times over the weeks prior and it always started up without too much delay - but then it just stopped. Finally I took the thing apart and found that it has a pump arrangement too but I cannot find a way that it works. The oil that I put in there should just leak down into the reservoir because there is nothing to stop it except the needle valve - hmm so that might be how it would work. I thought that the reason that the hydraulic pump failed was that the intake side's pipe was broken, I fixed it and it would not work yet, but maybe this would have worked.
Just got one of these used. Find the manual online. I just spent a few hours trying to fix mine and everything you need to know is in the free manual. Mine working great now. The primer plastic knob is held on by two very small Allen keys, one on either side of the knob (that's not in the manual)
Hey Gringo, did you get the 505 pumping? I have a Wagner 848 which is quite similar to what you are working on. One BIG problem you have is with old dried paint. It should be spotless inside. Start at the inlet valve and clean it! Get every speck of paint out of it. Then hold it with the open side up and fill it with water. It should hold water with nothing leaking out. With it full of water, put something like a pencil inside and push the valve open. The water should drain out. If it doesn't hold water, maybe you need a new inlet valve. Then take the head off again so you can see the diaphragm . Clean out every bit of old paint inside the paint chamber. The plastic disc inside is removable also. Take it out and clean all paint from there and replace the disc making sure you get it back in facing the same way it came apart. While you have it apart, you might as will replace the diaphragm. Next to the inlet valve is a hex plug. The outlet valve is under the plug. By the way your machine looks, you will probably find paint in there too. Under the plug you will find a spring and ball. The ball sits on the seat. Remove the seat with an allen wrench and replace it with a new one along with the ball and spring. On the side of the head is the recycling hose and the supply hose. The recycling hose slips onto the brass nipple with the other end going into the paint bucket. The supply hose screws onto the threaded nipple. Put your gun on the other end. The spray / prime knob that was loose is held on with two small allen srews . One on each side of the knob. After you have it all back together, put the machine on it's back so the inlet valve is pointing up and squirt a bunch of wd-40 into it and once again, push a pencil against the valve and let the wd40 go inside. Put the suction tube back onto the inlet valve, get it tight and upright the machine with the suction tube in a bucket of water. Be sure the spray / prime knob is on the prime side and the pressure switch is on the lowest setting. Fire up the machine and let it run for a little while. I usually need to turn the pressure knob up about half way or higher. It should prime itself after it runs for a while. When it finally gets primed, you should see water coming out the recycle tube. If it doesn't prime itself, don't bother trying to spray anything, it won't work if it isn't primed . After it primes itself, turn the pressure down to minimum. Whenever you change from spray to prime, or from prime to spray, be sure the pressure is adjusted to the minimum setting. After it is primed, switch it to spray and try spraying some water through it. You will need to increase the pressure, but it should work. Look online for the instruction manual, if you haven't already done so, it's available. Let me know how you're coming along with it.
Thanks for the info I haven’t been online in a while and I ended up selling this rig to a buddy of mine but I wish I would have read all this before I sold it.
Your diaphram its fine its your inlet valve that isn't working, get new ball and seat while you at it
I'm toying with the same sprayer, 505, same problem, but I also got it at the same price, so no big loss. But I am curious, did ya get it fixed?
No I never did I ended up selling it but I wasn’t online for a while and apparently it was an easy fix according to the people in the comments.
The problem is the inlet valve not the diaphragm..
The reason that you cannot get it to prime is probably due to the output valve being stuck. The little ball inside the valve is spring loaded and if the paint is allowed to build up inside, it sticks - and when I say it sticks, I mean it sort of glues itself to the seat of the valve and is very hard to get it loose. The prime 'switch' just has a set screw or two that have been opened so that they don't hold the knob in place. The prime switch is just a needle valve that is pulled open so that the output pressure is bypassed to the paint can. When the knob is turned to 'spray', the needle is closed so that the appropriated pressure is applied to the pressure hose and the gun.
Consider what you are willing to spend on this unit. I have a 400 which is very similar. I used it for several years - once in awhile, but it worked every time I tried it. Always it was hard to prime. Finally after a few years not using it, I had a situation where I thought I might need it, so I tried to get it to pump water. It did not want to but it finally did. It seemed to be operating so I put it to work on a fence using oil-based stain. I wasted a half gallon of $45 stain trying to get the thing to pump and spray. It would circulate into the can, but when I wanted it to spray, it plugged up.
So back to the shop, cleaned everything out and ready to go again after replacing the intake valve, the output valve and the diaphragm - to the tune of $129 - it should be ready to go. Cleaned out the filters and the gun etc. I went to test the unit, it would not prime! I opened the cover on the oil pump and discovered that the intake tube for the hydraulic pump was not only broken - it kinda disintegrated. So I found a piece of tubing to use in its place, refilled with oil and tried again, still did not prime. The hydraulic pump is not producing any pressure to actuate the diaphragm to produce pressure and intake vacuum for the paint portion of the system. The old parts did that, but now it doesn't.
And I cannot figure out how that hydraulic pump is supposed to work. I took it completely apart and can find no check valves or moving parts of any kind in the hydraulic system. There is nothing that I can see that would cause the pump to circulate oil. There is no way to create a vacuum except possibly the piston moving down, but there is nothing to keep the oil that is above in the chamber from coming back out as the piston comes down, so I don't see how it can possible stop the flow to create a vacuum or build up pressure. There is a needle, but it is used to regulate the pressure that the system builds up if the pump actually pumps the oil. That needle regulates the opening for escape of the oil back into the reservoir and there is no check valve on it either. What is supposed to happen is that the piston goes up and compresses the oil in the chamber where the diaphragm is located. That pressure causes the diaphragm to pressurize what ever liquid is on the other side and if the ball check output valve operates, the pressurized liquid is pushed out through the output valve, through the bypass and back to the paint can. At the same time, the intake valve operates causing a vacuum on the input side of the paint system so that more paint is pulled by vacuum into the intake side to be pressurized by the diaphragm's actions. If the diaphragm can be moved, the paint system on my Wagner 400 works fine, but the diaphragm does not see any pressure from the hydraulic pump any more. As the diaphragm is actuated by the hydraulic pressure, it will build up the pressure rapidly on the output side so that when the trigger on the gun is actuated, the pressure will force the paint out through the nozzle onto the surface. But without hydraulic pressure it cannot build up the spray pressure.
So the long and short of it is - if you decide to pay $130 for the kit to repair your 505, you might have thrown the money away because the hydraulic system is also bad or will fail shortly after you put it under pressure again. Like I said, I cannot figure out how the hydraulic pump works on this particular version of the Wagner hydraulic pump. I watched a video on a couple of other Wagner products one of which was very similar except the intake for the oil pump was in the piston itself. The repair video showed that the repairman was able to run the pump with the cover off and show that it was actually physically pumping the oil around. But on that one too, I could not see how the hydraulic pump operated. The piston had one hole in its side that I could see and no other way for oil to go in or out, yet that piston was supposed to be pumping the oil around? There had to be some form of check valves to cause the oil to stay once it was pumped and to create a vacuum when the piston went the opposite direction. This particular version had only the needle port to meter the oil when the pressure was too high, but I don't see how that pressure was developed. There has to be a check valve somewhere on the hydraulics side just as on the paint side. The paint side has a check valve on the intake and on the output. I suppose that the piston going into the cylinder would act as a check valve of sorts for the intake. And after the piston began to move up, the valve would be closed allowing the other end of the piston to cause pressurization, but without some kind of output check valve as there is on the paint side, I don't see how it works. For example, if there were a hole near the top
If someone knows how these pumps work, I would appreciate a clue be given to me. LOL
I had a similar problem on my wagner 635. I replaced the diaphragm and hydraulic fluid but it would still not even attempt to prime. What I found out is that before you install the new diaphragm, you must fill that cavity in the pump block that it sets into with hydraulic fluid. After doing this my spray primed and built pressure no problem. Not sure if this is the same scenario that you are experiencing, but I hope it helps.
@@scrubjaycyan4373 Thanks, that is an interesting idea. I will give it a try. The only thing is (well not the only thing, but one thing) that I had replaced the diaphragm several times over the weeks prior and it always started up without too much delay - but then it just stopped. Finally I took the thing apart and found that it has a pump arrangement too but I cannot find a way that it works. The oil that I put in there should just leak down into the reservoir because there is nothing to stop it except the needle valve - hmm so that might be how it would work. I thought that the reason that the hydraulic pump failed was that the intake side's pipe was broken, I fixed it and it would not work yet, but maybe this would have worked.
@@scrubjaycyan4373 Hi. You mean fill 100% the hidraulic housing with oil?
If it's the diaphragm cut a piece of rubber inner tube
Sir price please
what a hack. pull the damn valves and clean them out carefully.
Pleasse stopppp
Clean all the valves and check oil level