I have made my own gasket for the spool valve plate. If you look in the bolt hole between the spool valve and the valve body you will see that it is open to the valve body. That is the bolt that the washer goes on. Very good video. Thanks!
The inner upper bolt hole is drilled into the fluid passage so that is what the gasket seals also why there’s a washer on that bolt. You can put air into that hole and blow the piston out.
Really good instructs , have a 70 that is making too much pressure, I went through the top but something isn't right the unload valve seems to be the issue, already did the pressure relief valve thanks
I want to add to the thanks you are getting for the videos. I have a '55 850 that had some hiccupping issues especially with a sickle bar mounted and extended. It was like watching a diving board being used. I'm hoping the cylinder rebuild with unload valve service will solve the problem. I did find that the part #, from the NH online parts catalog, for the unload valve o-ring actually showed a "split seal" for my vintage tractor. That's what I ordered and it looks like a little piston ring. I had to fashion a sleeve that kept the ring compressed while I advanced it, in order to get it into the bushing. The chamfer on the lip of the bushing wasn't going to do it without the extra help. Any experience with one of these? My biggest concern is how far out of the bushing does the valve have to go in its full range of travel? Is the ring going to stay inside the bushing enough to stay compressed do you think? Is there any way to test that before I reassemble the top cover? I will say there was an o-ring in the valve when I disassembled it and it was definitely not doing anything to create a seal. It was shrunk and stiff and didn't extend far enough out of its seat to make contact with the inside of the bushing. If this split seal is the correct part it should do what it's supposed to do better than what was in there.
Reading the problem Kyflyboy had it sounds like he had that kind of ring in there and it failed. I would have gone with an o-ring but the I&T manual, and you as well, warn about putting a sub-standard one in there and it definitely looked like the old one wasn't a good one (though I have no idea how old it was) and I wanted to follow the spec. in the parts manual.
Never saw one with a split seal. Never messed with a 55 either but they were the first year for this design too. 53 and 54 are different. If the sickle was hiccupping I'd say the unload valve might've been bypassing a little fluid causing that. Thanks for the positive comment too.
These are great videos! Very in depth and informative. I am currently working on doing a short rebuild on my ‘64 Ford 4000. I have a question you might be able to answer. I had a 400 pound grader blade on the tractor and using it to clean out a drainage ditch. After using it for a while the blade would not go down. It was stuck in the up position. There was nothing I could do to make it go back down. I was in position control while using the grader blade. I switched between draft and position and that didn’t change anything. So I pulled the tractor into the shop and used a hoist to take the blade off the tractor. During disassembly I loosened the valve in the top cover and all the oil pressure released and the arms came down. So, my question is, what would cause the lift arms with a 400 pound implement attached to get stuck in the up position and not come back down? I hope you can help. I haven’t found anything that is just an obvious reason. Oh, also, hydraulic oil was coming out of the hydraulic pump while this was happening. The oil was coming out of the seam in the pump case that does not have the o-ring. I have already rebuilt the pump and put it back together. I didn’t find any issues in the pump. Thanks!
My first thought would be the unload valve sticking. Sounds like the system is building a lot of pressure to be shooting oil out of the pump. The pressure relief valve might not functioning either. They are supposed to pop off at 2000 psi. At one time I had a very heavy disc harrow stay up on my 861-D. The nut for the draft adjustment came off and allowed the disc to stay up. I had the tractor in position control too. Pretty sure I mentioned and pointed out that nut in the top cover rebuild video if you want to check yours. Mine would actually drop after the tractor was shut off for a while though with the disc on it. Without the disc I had to remove the hydraulic block off plate to relieve the oil pressure.
@@chickenhousemechanic thanks for the reply. I was thinking about the unload valve as well. I may have acted too quickly and assumed the worse by taking it apart. It may have eventually gone down on its own after a while. I probably shoulda just used the hoist to relieve the pressure and left it overnight. But with oil coming out on f the pump I just assume something failed and it was pumping against itself. I’ll probably send another question. Lol. Thanks again!
Well, I took apart the lift cylinder and think I found the problem. 2 things. When I took out the plug (part #39 of illustration FO-246 in the I&T FO-20 manual) to access the unloading valve, there were a few small pieces of metal that were once in the shape of a ring. Upon looking into the bore behind the plug, I could see the rest of the pieces of that ring on the outside of the of the unloading valve bushing (part #40). I am not sure why there was a metal ring there but it was a perfect fit. I couldn’t tell if it had originally been attached to the plug or if it was an additional part that had been added. Is there a little ring, like a lip, at the end of that plug that would fit perfectly around that end of the bushing? The illustrations are not detailed enough to show that end of the plug. Also, when I removed the spool portion of the unloading valve (part #45), I found there was no o-ring (part #44) on it. This is kinda strange but when I took the hyd. pump apart, as I was taking it off the tractor, I found an extra, loose o-ring in the process. I wasn’t sure where it came from but I think I know now. So I am fairly certain that this is the “smoking gun” I was looking for. What are your thoughts? I have a Ford/New Holland dealer about 15 miles away and they have the right o-ring (NCA836B) in stock for only about $5. Not too bad for a dealer part. Thanks
@@kyflyboy965 I don't have access to an I&T manual but I think I know what you're asking. The plug that you remove to access the unload valve has a H cross section. There is a chance that plug is broken. The spool valve not having an o-ring would surely cause the lift to not lower. If that plug is broken I'd replace it because from the way the bore is designed that plug might be a stop for the valve and if not the proper size could cause all kind of issues.
@@kyflyboy965 I have seen pieces of the springs from the pump in the valve body before. Just sayin. Not sure what is going on with your system except the unloading valve definitely needs an o'ring for the lift to work.
Your videos have proved invaluable to me. Thank you so much!
I have made my own gasket for the spool valve plate. If you look in the bolt hole between the spool valve and the valve body you will see that it is open to the valve body. That is the bolt that the washer goes on. Very good video. Thanks!
The inner upper bolt hole is drilled into the fluid passage so that is what the gasket seals also why there’s a washer on that bolt. You can put air into that hole and blow the piston out.
Really good instructs , have a 70 that is making too much pressure, I went through the top but something isn't right the unload valve seems to be the issue, already did the pressure relief valve thanks
o-ring part # 9626944, which is a replacement for original # NCA836B
I want to add to the thanks you are getting for the videos. I have a '55 850 that had some hiccupping issues especially with a sickle bar mounted and extended. It was like watching a diving board being used. I'm hoping the cylinder rebuild with unload valve service will solve the problem. I did find that the part #, from the NH online parts catalog, for the unload valve o-ring actually showed a "split seal" for my vintage tractor. That's what I ordered and it looks like a little piston ring. I had to fashion a sleeve that kept the ring compressed while I advanced it, in order to get it into the bushing. The chamfer on the lip of the bushing wasn't going to do it without the extra help. Any experience with one of these? My biggest concern is how far out of the bushing does the valve have to go in its full range of travel? Is the ring going to stay inside the bushing enough to stay compressed do you think? Is there any way to test that before I reassemble the top cover? I will say there was an o-ring in the valve when I disassembled it and it was definitely not doing anything to create a seal. It was shrunk and stiff and didn't extend far enough out of its seat to make contact with the inside of the bushing. If this split seal is the correct part it should do what it's supposed to do better than what was in there.
Reading the problem Kyflyboy had it sounds like he had that kind of ring in there and it failed. I would have gone with an o-ring but the I&T manual, and you as well, warn about putting a sub-standard one in there and it definitely looked like the old one wasn't a good one (though I have no idea how old it was) and I wanted to follow the spec. in the parts manual.
Never saw one with a split seal. Never messed with a 55 either but they were the first year for this design too. 53 and 54 are different. If the sickle was hiccupping I'd say the unload valve might've been bypassing a little fluid causing that. Thanks for the positive comment too.
These are great videos! Very in depth and informative. I am currently working on doing a short rebuild on my ‘64 Ford 4000. I have a question you might be able to answer. I had a 400 pound grader blade on the tractor and using it to clean out a drainage ditch. After using it for a while the blade would not go down. It was stuck in the up position. There was nothing I could do to make it go back down. I was in position control while using the grader blade. I switched between draft and position and that didn’t change anything. So I pulled the tractor into the shop and used a hoist to take the blade off the tractor. During disassembly I loosened the valve in the top cover and all the oil pressure released and the arms came down. So, my question is, what would cause the lift arms with a 400 pound implement attached to get stuck in the up position and not come back down? I hope you can help. I haven’t found anything that is just an obvious reason. Oh, also, hydraulic oil was coming out of the hydraulic pump while this was happening. The oil was coming out of the seam in the pump case that does not have the o-ring. I have already rebuilt the pump and put it back together. I didn’t find any issues in the pump. Thanks!
My first thought would be the unload valve sticking. Sounds like the system is building a lot of pressure to be shooting oil out of the pump. The pressure relief valve might not functioning either. They are supposed to pop off at 2000 psi.
At one time I had a very heavy disc harrow stay up on my 861-D. The nut for the draft adjustment came off and allowed the disc to stay up. I had the tractor in position control too. Pretty sure I mentioned and pointed out that nut in the top cover rebuild video if you want to check yours. Mine would actually drop after the tractor was shut off for a while though with the disc on it. Without the disc I had to remove the hydraulic block off plate to relieve the oil pressure.
@@chickenhousemechanic thanks for the reply. I was thinking about the unload valve as well. I may have acted too quickly and assumed the worse by taking it apart. It may have eventually gone down on its own after a while. I probably shoulda just used the hoist to relieve the pressure and left it overnight. But with oil coming out on f the pump I just assume something failed and it was pumping against itself. I’ll probably send another question. Lol. Thanks again!
Well, I took apart the lift cylinder and think I found the problem. 2 things. When I took out the plug (part #39 of illustration FO-246 in the I&T FO-20 manual) to access the unloading valve, there were a few small pieces of metal that were once in the shape of a ring. Upon looking into the bore behind the plug, I could see the rest of the pieces of that ring on the outside of the of the unloading valve bushing (part #40). I am not sure why there was a metal ring there but it was a perfect fit. I couldn’t tell if it had originally been attached to the plug or if it was an additional part that had been added. Is there a little ring, like a lip, at the end of that plug that would fit perfectly around that end of the bushing? The illustrations are not detailed enough to show that end of the plug. Also, when I removed the spool portion of the unloading valve (part #45), I found there was no o-ring (part #44) on it. This is kinda strange but when I took the hyd. pump apart, as I was taking it off the tractor, I found an extra, loose o-ring in the process. I wasn’t sure where it came from but I think I know now. So I am fairly certain that this is the “smoking gun” I was looking for. What are your thoughts? I have a Ford/New Holland dealer about 15 miles away and they have the right o-ring (NCA836B) in stock for only about $5. Not too bad for a dealer part.
Thanks
@@kyflyboy965 I don't have access to an I&T manual but I think I know what you're asking. The plug that you remove to access the unload valve has a H cross section. There is a chance that plug is broken. The spool valve not having an o-ring would surely cause the lift to not lower. If that plug is broken I'd replace it because from the way the bore is designed that plug might be a stop for the valve and if not the proper size could cause all kind of issues.
@@kyflyboy965 I have seen pieces of the springs from the pump in the valve body before. Just sayin. Not sure what is going on with your system except the unloading valve definitely needs an o'ring for the lift to work.
Looks like you been on snapon truck again Lololo
500.00 bucks worth again