1954 ford 650 lift not working

ford_650

Member
just purchased a 56 ford 650 tractor. i got it running and the lift did NOT work. i put in all new o-rings including the lift piston and unloader valve. still nothing. the pump seems to be working good when i removed the 3x5 plate there was a good stream coming out...any suggestions or where to check next?
 
been awhile but isn't there a pressure relief valve by your piston. sounds like its stuck open
 
yes sir, i took the pressure relief valve off and cleaned it, didn't see any issues with it. the spring seemed strong and the check valve seemed to seal
 
sounds as though you linkage isn't working correctly. when you raise your lever it should start putting oil to the piston to raise the 3 pt. maybe something is slipping inside.
 
(quoted from post at 12:41:46 05/09/19) sounds as though you linkage isn't working correctly. when you raise your lever it should start putting oil to the piston to raise the 3 pt. maybe something is slipping inside.
i checked the pin,linkage and control valve, all looked good...when i rebuilt the lift cylinder i adjusted the control valve and linkage per specs.
i pulled the plug/test port off the 3x5 adapter plate when i got home today, there was no fluid present. from what i have read on here that means the check valve is not opening...low pressure from pump? i know its pumping because when i remove the 3x5 adapter plate fluid streams good
 
(quoted from post at 17:14:12 05/09/19)
(quoted from post at 12:41:46 05/09/19) sounds as though you linkage isn't working correctly. when you raise your lever it should start putting oil to the piston to raise the 3 pt. maybe something is slipping inside.
i checked the pin,linkage and control valve, all looked good...when i rebuilt the lift cylinder i adjusted the control valve and linkage per specs.
i pulled the plug/test port off the 3x5 adapter plate when i got home today, there was no fluid present. from what i have read on here that means the check valve is not opening...low pressure from pump? i know its pumping because when i remove the 3x5 adapter plate fluid streams good
when i remove the 3x5 adapter plate fluid streams good"....AND "i pulled the plug/test port off the 3x5 adapter plate when i got home today, there was no fluid present." Says pump is moving oil, but the pressure is low as long as unloader valve is unloading/bypassing. Too low to open check valve, thus nothing at test port.
 
(quoted from post at 17:58:29 05/09/19) thanks JMOR!
I'm thinking i need to rebuild hydraulic pump(piston type), seems like my next step?
would check pump pressure first. Even if you don't have a gauge, you will know if pump is loading engine and/or hear the relief valve squeal. Block as shown here.
SPB82ug.jpg
 
(quoted from post at 23:34:47 05/09/19)
(quoted from post at 17:58:29 05/09/19) thanks JMOR!
I'm thinking i need to rebuild hydraulic pump(piston type), seems like my next step?
would check pump pressure first. Even if you don't have a gauge, you will know if pump is loading engine and/or hear the relief valve squeal. Block as shown here.
SPB82ug.jpg
just put plate as shown, i thought i heard the valve squel several times, it also sounded like there was fluid going to the sump
i do not have a gauge yet to check pressure
 

just to double check i went back out and put plate on for pressure test and started tractor, i pulled the hydraulic fill cap off to look inside...definitely heard high pitch whistle from valve, and tractor/pump sounded like it was under a load.
 
(quoted from post at 20:05:58 05/09/19)
just to double check i went back out and put plate on for pressure test and started tractor, i pulled the hydraulic fill cap off to look inside...definitely heard high pitch whistle from valve, and tractor/pump sounded like it was under a load.
hen I might be looking somewhere besides the pump. I know you think it is all good, but to me, the unloader is prime suspect, unless you assembled the check valve wrong as the fellow did in the other post you made.
 
(quoted from post at 05:12:55 05/10/19)
(quoted from post at 20:05:58 05/09/19)
just to double check i went back out and put plate on for pressure test and started tractor, i pulled the hydraulic fill cap off to look inside...definitely heard high pitch whistle from valve, and tractor/pump sounded like it was under a load.
hen I might be looking somewhere besides the pump. I know you think it is all good, but to me, the unloader is prime suspect, unless you assembled the check valve wrong as the fellow did in the other post you made.
i pulled the unloader valve, not sure if it was stuck when i did that. i put new o-ring on it and made sure it moved as should with new o-ring. is it possible thats not assembled right? there is a bushing i took out and cleaned and put back the way it was installed. the guy that owned it before me did work on the hydraulics and im not sure what he took apart before i got it. i did take the check valve out and cleaned/checked it.
 
(quoted from post at 11:51:44 05/10/19)
(quoted from post at 05:12:55 05/10/19)
(quoted from post at 20:05:58 05/09/19)
just to double check i went back out and put plate on for pressure test and started tractor, i pulled the hydraulic fill cap off to look inside...definitely heard high pitch whistle from valve, and tractor/pump sounded like it was under a load.
hen I might be looking somewhere besides the pump. I know you think it is all good, but to me, the unloader is prime suspect, unless you assembled the check valve wrong as the fellow did in the other post you made.
i pulled the unloader valve, not sure if it was stuck when i did that. i put new o-ring on it and made sure it moved as should with new o-ring. is it possible thats not assembled right? there is a bushing i took out and cleaned and put back the way it was installed. the guy that owned it before me did work on the hydraulics and im not sure what he took apart before i got it. i did take the check valve out and cleaned/checked it.
mvphoto35967.jpg
 
(quoted from post at 12:20:23 05/10/19)
(quoted from post at 11:51:44 05/10/19)
(quoted from post at 05:12:55 05/10/19)
(quoted from post at 20:05:58 05/09/19)
just to double check i went back out and put plate on for pressure test and started tractor, i pulled the hydraulic fill cap off to look inside...definitely heard high pitch whistle from valve, and tractor/pump sounded like it was under a load.
hen I might be looking somewhere besides the pump. I know you think it is all good, but to me, the unloader is prime suspect, unless you assembled the check valve wrong as the fellow did in the other post you made.
i pulled the unloader valve, not sure if it was stuck when i did that. i put new o-ring on it and made sure it moved as should with new o-ring. is it possible thats not assembled right? there is a bushing i took out and cleaned and put back the way it was installed. the guy that owned it before me did work on the hydraulics and im not sure what he took apart before i got it. i did take the check valve out and cleaned/checked it.
mvphoto35967.jpg
is it possible to remove check valve for troubleshooting? and see what lift does?
 
(quoted from post at 07:22:27 05/10/19)
(quoted from post at 12:20:23 05/10/19)
(quoted from post at 11:51:44 05/10/19)
(quoted from post at 05:12:55 05/10/19)
(quoted from post at 20:05:58 05/09/19)
just to double check i went back out and put plate on for pressure test and started tractor, i pulled the hydraulic fill cap off to look inside...definitely heard high pitch whistle from valve, and tractor/pump sounded like it was under a load.
hen I might be looking somewhere besides the pump. I know you think it is all good, but to me, the unloader is prime suspect, unless you assembled the check valve wrong as the fellow did in the other post you made.
i pulled the unloader valve, not sure if it was stuck when i did that. i put new o-ring on it and made sure it moved as should with new o-ring. is it possible thats not assembled right? there is a bushing i took out and cleaned and put back the way it was installed. the guy that owned it before me did work on the hydraulics and im not sure what he took apart before i got it. i did take the check valve out and cleaned/checked it.
mvphoto35967.jpg
is it possible to remove check valve for troubleshooting? and see what lift does?
don't see any reason why not. Without weight on lift, the arms may rise without touch control command , lifting on back pressure alone. But whatever it does may give useful information for troubleshooting.
 
(quoted from post at 15:08:35 05/10/19)
(quoted from post at 07:22:27 05/10/19)
(quoted from post at 12:20:23 05/10/19)
(quoted from post at 11:51:44 05/10/19)
(quoted from post at 05:12:55 05/10/19)
(quoted from post at 20:05:58 05/09/19)
just to double check i went back out and put plate on for pressure test and started tractor, i pulled the hydraulic fill cap off to look inside...definitely heard high pitch whistle from valve, and tractor/pump sounded like it was under a load.
hen I might be looking somewhere besides the pump. I know you think it is all good, but to me, the unloader is prime suspect, unless you assembled the check valve wrong as the fellow did in the other post you made.
i pulled the unloader valve, not sure if it was stuck when i did that. i put new o-ring on it and made sure it moved as should with new o-ring. is it possible thats not assembled right? there is a bushing i took out and cleaned and put back the way it was installed. the guy that owned it before me did work on the hydraulics and im not sure what he took apart before i got it. i did take the check valve out and cleaned/checked it.
mvphoto35967.jpg
is it possible to remove check valve for troubleshooting? and see what lift does?
don't see any reason why not. Without weight on lift, the arms may rise without touch control command , lifting on back pressure alone. But whatever it does may give useful information for troubleshooting.
just got home and i pulled the check valve(appeared to be in correctly) started the tractor and the arms lifted with control lever up or down. i was able to push them down using my weight, they would rise back up
 
(quoted from post at 17:00:22 05/10/19)
(quoted from post at 15:08:35 05/10/19)
(quoted from post at 07:22:27 05/10/19)
(quoted from post at 12:20:23 05/10/19)
(quoted from post at 11:51:44 05/10/19)
(quoted from post at 05:12:55 05/10/19)
(quoted from post at 20:05:58 05/09/19)
just to double check i went back out and put plate on for pressure test and started tractor, i pulled the hydraulic fill cap off to look inside...definitely heard high pitch whistle from valve, and tractor/pump sounded like it was under a load.
hen I might be looking somewhere besides the pump. I know you think it is all good, but to me, the unloader is prime suspect, unless you assembled the check valve wrong as the fellow did in the other post you made.
i pulled the unloader valve, not sure if it was stuck when i did that. i put new o-ring on it and made sure it moved as should with new o-ring. is it possible thats not assembled right? there is a bushing i took out and cleaned and put back the way it was installed. the guy that owned it before me did work on the hydraulics and im not sure what he took apart before i got it. i did take the check valve out and cleaned/checked it.
mvphoto35967.jpg
is it possible to remove check valve for troubleshooting? and see what lift does?
don't see any reason why not. Without weight on lift, the arms may rise without touch control command , lifting on back pressure alone. But whatever it does may give useful information for troubleshooting.
just got home and i pulled the check valve(appeared to be in correctly) started the tractor and the arms lifted with control lever up or down. i was able to push them down using my weight, they would rise back up
xactly as I expected.
 
(quoted from post at 17:06:10 05/10/19)
(quoted from post at 17:00:22 05/10/19)
(quoted from post at 15:08:35 05/10/19)
(quoted from post at 07:22:27 05/10/19)
(quoted from post at 12:20:23 05/10/19)
(quoted from post at 11:51:44 05/10/19)
(quoted from post at 05:12:55 05/10/19)
(quoted from post at 20:05:58 05/09/19)
just to double check i went back out and put plate on for pressure test and started tractor, i pulled the hydraulic fill cap off to look inside...definitely heard high pitch whistle from valve, and tractor/pump sounded like it was under a load.
hen I might be looking somewhere besides the pump. I know you think it is all good, but to me, the unloader is prime suspect, unless you assembled the check valve wrong as the fellow did in the other post you made.
i pulled the unloader valve, not sure if it was stuck when i did that. i put new o-ring on it and made sure it moved as should with new o-ring. is it possible thats not assembled right? there is a bushing i took out and cleaned and put back the way it was installed. the guy that owned it before me did work on the hydraulics and im not sure what he took apart before i got it. i did take the check valve out and cleaned/checked it.
mvphoto35967.jpg
is it possible to remove check valve for troubleshooting? and see what lift does?
don't see any reason why not. Without weight on lift, the arms may rise without touch control command , lifting on back pressure alone. But whatever it does may give useful information for troubleshooting.
just got home and i pulled the check valve(appeared to be in correctly) started the tractor and the arms lifted with control lever up or down. i was able to push them down using my weight, they would rise back up
xactly as I expected.
t this pointthe easiest thing to do is to use Overland posters wire probe to try to determine whether unloader valve is moving or not.
"I was manipulating the unloading valve with a bent piece of wire. I need to look a bit closer at the diagrams to see exactly what I was doing, but from the control valve side of the cylinder with my hand through the shift cover, I could hold the valve at the bottom of its travel and observe no noise or turbulence. Releasing the valve (with the touch control up) would allow it to move back, which would load the engine a moment and blow the valve in the sump. The turbulence I assume coming from the valve under the oil. "
Me, "When you push the unloader valve in with the wire probe, you push it to the unload position. Then upon commanding lift, it jumps back to the position for lifting (blocks unload flow) and the next thing that should happen is that the check valve should open, allowing flow to ram (past the test port on accessory plate)'.

IF the unloader is found to be moving, then I will fall back to the position that since it never worked since you acquired it, and you said previous owner had removed/assembled various parts, that perhaps he put the valve bushings in incorrectly and some passages are not connected properly. I am not absolutely sure that those 3 bushings could be installed incorrectly, but believe that it is possible.
 
(quoted from post at 22:35:20 05/10/19)
(quoted from post at 17:06:10 05/10/19)
(quoted from post at 17:00:22 05/10/19)
(quoted from post at 15:08:35 05/10/19)
(quoted from post at 07:22:27 05/10/19)
(quoted from post at 12:20:23 05/10/19)
(quoted from post at 11:51:44 05/10/19)
(quoted from post at 05:12:55 05/10/19)
(quoted from post at 20:05:58 05/09/19)
just to double check i went back out and put plate on for pressure test and started tractor, i pulled the hydraulic fill cap off to look inside...definitely heard high pitch whistle from valve, and tractor/pump sounded like it was under a load.
hen I might be looking somewhere besides the pump. I know you think it is all good, but to me, the unloader is prime suspect, unless you assembled the check valve wrong as the fellow did in the other post you made.
i pulled the unloader valve, not sure if it was stuck when i did that. i put new o-ring on it and made sure it moved as should with new o-ring. is it possible thats not assembled right? there is a bushing i took out and cleaned and put back the way it was installed. the guy that owned it before me did work on the hydraulics and im not sure what he took apart before i got it. i did take the check valve out and cleaned/checked it.
mvphoto35967.jpg
is it possible to remove check valve for troubleshooting? and see what lift does?
don't see any reason why not. Without weight on lift, the arms may rise without touch control command , lifting on back pressure alone. But whatever it does may give useful information for troubleshooting.
just got home and i pulled the check valve(appeared to be in correctly) started the tractor and the arms lifted with control lever up or down. i was able to push them down using my weight, they would rise back up
xactly as I expected.
t this pointthe easiest thing to do is to use Overland posters wire probe to try to determine whether unloader valve is moving or not.
"I was manipulating the unloading valve with a bent piece of wire. I need to look a bit closer at the diagrams to see exactly what I was doing, but from the control valve side of the cylinder with my hand through the shift cover, I could hold the valve at the bottom of its travel and observe no noise or turbulence. Releasing the valve (with the touch control up) would allow it to move back, which would load the engine a moment and blow the valve in the sump. The turbulence I assume coming from the valve under the oil. "
Me, "When you push the unloader valve in with the wire probe, you push it to the unload position. Then upon commanding lift, it jumps back to the position for lifting (blocks unload flow) and the next thing that should happen is that the check valve should open, allowing flow to ram (past the test port on accessory plate)'.

IF the unloader is found to be moving, then I will fall back to the position that since it never worked since you acquired it, and you said previous owner had removed/assembled various parts, that perhaps he put the valve bushings in incorrectly and some passages are not connected properly. I am not absolutely sure that those 3 bushings could be installed incorrectly, but believe that it is possible.
thanks for your assistance, im getting ready to check that and will post back shortly
 
i pulled the side plate:
with the control lever down fluid was streaming out the control valve towards rear of tractor, when control arm was raised fluid stopped. the unloader valve was all the forward towards the front of tractor. i was not able to get a wire to the front side to push back on it. i was able to come in from accessible side and it seemed it was all the way forward when i probed it with wire(used a coat hanger)
 
(quoted from post at 23:59:47 05/10/19) just remembered, i couldnt manipulate unloader valve from other side anyways. the plate blocks it

JMOR, while im waiting your response about the unloader valve...

im wondering if i need a pressure gauge to test, looking at an old manual i have it says:
install gauge at pipe plug location on side, remove accessory plate and reinstall (like you showed me earlier). run tractor at 600rpm "at which time the relief valve should unseat as indicated by buzzing or bubbling of oil in center housing near valve. the pressure gauge should read 1950-2050psi as relief valve unseats. if it unseats less than 1950psi, renew valve and recheck.then if valve doesnt unseat and pressure remains low renew or recondition pump."

thoughts?

Thanks!
 
(quoted from post at 18:53:17 05/10/19) i pulled the side plate:
with the control lever down fluid was streaming out the control valve towards rear of tractor, when control arm was raised fluid stopped. the unloader valve was all the forward towards the front of tractor. i was not able to get a wire to the front side to push back on it. i was able to come in from accessible side and it seemed it was all the way forward when i probed it with wire(used a coat hanger)
treaming out control valve isn't right. Perhaps dripping OK. Sounds as though you found unloader in the unload position. That is fine, but you should feel it move to the opposite position (pushing the wire outwards) when you move touch control lever to lift position. If not then unload valve is either stuck or there is incorrect assembly as discussed earlier. It must move or there can be no lift.
 
In addition, I feel sure that you have read by now that the unloader O-ring is very sensitive to exact size, material qualities that might relate to swelling, etc., all of which can make it require too much force to move.
 
(quoted from post at 13:22:48 05/11/19) In addition, I feel sure that you have read by now that the unloader O-ring is very sensitive to exact size, material qualities that might relate to swelling, etc., all of which can make it require too much force to move.
the o-ring seemed fine when I installed it and it should be the correct one I ordered:
NCA836B Years:1953-64 O-Ring Hydraulic Lift Unload Valve

With the fluid streaming out the rear of control valve with lift lever down, im wondering if that was assembled incorrectly, ill try to post a video or pic shortly
 
(quoted from post at 15:14:25 05/11/19)
(quoted from post at 13:22:48 05/11/19) In addition, I feel sure that you have read by now that the unloader O-ring is very sensitive to exact size, material qualities that might relate to swelling, etc., all of which can make it require too much force to move.
the o-ring seemed fine when I installed it and it should be the correct one I ordered:
NCA836B Years:1953-64 O-Ring Hydraulic Lift Unload Valve

With the fluid streaming out the rear of control valve with lift lever down, im wondering if that was assembled incorrectly, ill try to post a video or pic shortly
 
(quoted from post at 15:14:25 05/11/19)
(quoted from post at 13:22:48 05/11/19) In addition, I feel sure that you have read by now that the unloader O-ring is very sensitive to exact size, material qualities that might relate to swelling, etc., all of which can make it require too much force to move.
the o-ring seemed fine when I installed it and it should be the correct one I ordered:
NCA836B Years:1953-64 O-Ring Hydraulic Lift Unload Valve

With the fluid streaming out the rear of control valve with lift lever down, im wondering if that was assembled incorrectly, ill try to post a video or pic shortly
mvphoto35994.jpg
 
(quoted from post at 10:31:16 05/11/19)
(quoted from post at 15:14:25 05/11/19)
(quoted from post at 13:22:48 05/11/19) In addition, I feel sure that you have read by now that the unloader O-ring is very sensitive to exact size, material qualities that might relate to swelling, etc., all of which can make it require too much force to move.
the o-ring seemed fine when I installed it and it should be the correct one I ordered:
NCA836B Years:1953-64 O-Ring Hydraulic Lift Unload Valve

With the fluid streaming out the rear of control valve with lift lever down, im wondering if that was assembled incorrectly, ill try to post a video or pic shortly
mvphoto35994.jpg
efinitely something wrong there. Picture not great, but it looks like control spool too far out to me.
 
about to be away from computer for the day, so putting up these as a just -in-case. Still see post on cell.
PfmqabN.jpg

aa3r20k.jpg

aMC9Gx4.jpg
 
thanks JMOR, i really appreciate your assistance.
just got back inside, i pulled the lift cover and removed the unloading valve and bushings, reassembled....i made sure bore holes in cylinder aligned with holes in bushing and followed manual instructions for reassembly. i was thinking it may work but unfortunately it didnt :(
the unloading valve moved freely in bore and seemed to have the right resistance with the new o-ring. i made sure unloading valve was all the way in. i reassembled and started tractor, still nothing. i moved the unload valve towards front of tractor with wire. still nothing.
is it possible the relief valve is bad or pump? and its low pressure? ill have a gauge to test it monday or tuesday. im new to working on hydraulics
 
(quoted from post at 13:37:00 05/11/19) thanks JMOR, i really appreciate your assistance.
just got back inside, i pulled the lift cover and removed the unloading valve and bushings, reassembled....i made sure bore holes in cylinder aligned with holes in bushing and followed manual instructions for reassembly. i was thinking it may work but unfortunately it didnt :(
the unloading valve moved freely in bore and seemed to have the right resistance with the new o-ring. i made sure unloading valve was all the way in. i reassembled and started tractor, still nothing. i moved the unload valve towards front of tractor with wire. still nothing.
is it possible the relief valve is bad or pump? and its low pressure? ill have a gauge to test it monday or tuesday. im new to working on hydraulics
ith that stream out of control valve I would check its bushing too. End with wide flange needs to be front or rear. See manual
 
Just pulled the lift cover, removed control bushing and spool, they were installed correctly going by the manual i have. the wide flange on bushing drives in from the open cylinder side, thus the narrow land is closest to open end of cylinder. cleaned oiled and reinstalled. same symptoms
 
(quoted from post at 17:01:05 05/11/19)
mvphoto35999.jpg
here is that leakage flow in your photo coming from? Between spool and bushing or between bushing and casting of housing?
 
(quoted from post at 09:16:55 05/12/19)
(quoted from post at 17:01:05 05/11/19)
mvphoto35999.jpg
here is that leakage flow in your photo coming from? Between spool and bushing or between bushing and casting of housing?
it looks to be coming from in between spool and bushing while lift arm lever is lowered. as i begin to raise it and spool goes forward it stops.
is it possible that since check valve is not opening that the relief valve is bad and opening/relieving pressure too soon? i cant get my head around the plumbing and valves
 
(quoted from post at 08:43:51 05/12/19)
(quoted from post at 09:16:55 05/12/19)
(quoted from post at 17:01:05 05/11/19)
mvphoto35999.jpg
here is that leakage flow in your photo coming from? Between spool and bushing or between bushing and casting of housing?
it looks to be coming from in between spool and bushing while lift arm lever is lowered. as i begin to raise it and spool goes forward it stops.
is it possible that since check valve is not opening that the relief valve is bad and opening/relieving pressure too soon? i cant get my head around the plumbing and valves
y opinion is that control spool is coming out too far and not being pushed in far enough. Try adjusting turnbuckle. Maybe even using big screwdriver to push it in further while lift command.
 
(quoted from post at 10:11:41 05/12/19)
(quoted from post at 08:43:51 05/12/19)
(quoted from post at 09:16:55 05/12/19)
(quoted from post at 17:01:05 05/11/19)
mvphoto35999.jpg
here is that leakage flow in your photo coming from? Between spool and bushing or between bushing and casting of housing?
it looks to be coming from in between spool and bushing while lift arm lever is lowered. as i begin to raise it and spool goes forward it stops.
is it possible that since check valve is not opening that the relief valve is bad and opening/relieving pressure too soon? i cant get my head around the plumbing and valves
y opinion is that control spool is coming out too far and not being pushed in far enough. Try adjusting turnbuckle. Maybe even using big screwdriver to push it in further while lift command.
mvphoto36050.jpg

Here's a pic of spool, I suspected that yesterday I adjusted the turnbuckle so that when lever is raised spool bottoms out on plate going all the way in
 
since others have been in there before you, anything is possible. Spool to bushing clearance should be less than 0.001"
 
clearances seem right on spool and bushing, not moving freely but some resistance as expected on machined surfaces.
at this point ill wait for pressure gauge and see where i am with that, if pressure checks out good and relief valve blows @ approx 2000psi im back to square one. what about the back pressure valve? i have not removed it but i did stick a screwdriver in and made sure it was moving, spring pressure seemed light, not like the spring in check valve
 
(quoted from post at 10:51:01 05/12/19) clearances seem right on spool and bushing, not moving freely but some resistance as expected on machined surfaces.
at this point ill wait for pressure gauge and see where i am with that, if pressure checks out good and relief valve blows @ approx 2000psi im back to square one. what about the back pressure valve? i have not removed it but i did stick a screwdriver in and made sure it was moving, spring pressure seemed light, not like the spring in check valve
believe check opens around 115 psi and back pressure around 40psi. Any resolution on all that leak/flow out control spool? Your wire probe indicated that unloader never moved away from unload position, correct?
 
(quoted from post at 16:47:41 05/12/19)
(quoted from post at 10:51:01 05/12/19) clearances seem right on spool and bushing, not moving freely but some resistance as expected on machined surfaces.
at this point ill wait for pressure gauge and see where i am with that, if pressure checks out good and relief valve blows @ approx 2000psi im back to square one. what about the back pressure valve? i have not removed it but i did stick a screwdriver in and made sure it was moving, spring pressure seemed light, not like the spring in check valve
believe check opens around 115 psi and back pressure around 40psi. Any resolution on all that leak/flow out control spool? Your wire probe indicated that unloader never moved away from unload position, correct?
Correct on unload valve, I can move it forward with wire probe towards front of tractor...it stays there and wont return back,.
I'm not sure on the control valve spool, is it suppose to do that? As best I could tell the bushing is in correctly.
Earlier troubleshooting indicated check valve not opening, which perhaps points to unload valve...that is in unload position all the way correct? If so shouldn't that route fluid to check valve and if not enough pressure to open it would go to back flow valve.
Thanks for your assistance, I'll know more about the pressure tomorrow and see where that leads...
 
Attaching several diagrams showing what paths are open to flow and which are blocked at LIFT, HOLD, LOWER. Note that nothing ever blocks flow TO back pressure valve, but
unloader does block outflow from backpressure valve during LIFT. This by the way is what is NOT happening in your case, thus no lift. If you wish to discuss, my e-mail
is open on YT safe messenger, and I will reply to your e-mail and thru that method we can exchange phone numbers.
RPOy3Bu.jpg
https://i.imgur.com/ggQRezY.jpg[/img]
1eb4ulC.jpg

XlceFbC.jpg
 
(quoted from post at 18:41:56 05/12/19) Attaching several diagrams showing what paths are open to flow and which are blocked at LIFT, HOLD, LOWER. Note that nothing ever blocks flow TO back pressure valve, but
unloader does block outflow from backpressure valve during LIFT. This by the way is what is NOT happening in your case, thus no lift. If you wish to discuss, my e-mail
is open on YT safe messenger, and I will reply to your e-mail and thru that method we can exchange phone numbers.
m8qhXIz.jpg

RPOy3Bu.jpg

ggQRezY.jpg

1eb4ulC.jpg

XlceFbC.jpg
Thanks JMOR, cant see the pics but I'm on my phone, will check when I get home. I couldn't see your email
.
I made mine available too in case you can see it. Will check that too when I get home on my PC
Thanks!
 
(quoted from post at 19:12:59 05/12/19)
(quoted from post at 18:41:56 05/12/19) Attaching several diagrams showing what paths are open to flow and which are blocked at LIFT, HOLD, LOWER. Note that nothing ever blocks flow TO back pressure valve, but
unloader does block outflow from backpressure valve during LIFT. This by the way is what is NOT happening in your case, thus no lift. If you wish to discuss, my e-mail
is open on YT safe messenger, and I will reply to your e-mail and thru that method we can exchange phone numbers.
m8qhXIz.jpg

RPOy3Bu.jpg

ggQRezY.jpg

1eb4ulC.jpg

XlceFbC.jpg
Thanks JMOR, cant see the pics but I'm on my phone, will check when I get home. I couldn't see your email
.
I made mine available too in case you can see it. Will check that too when I get home on my PC
Thanks!
I will keep this updated until its repaired. Yesterday I attempted to do a pressure test with gauge but the gasket on pump started leaking. Pulled pump and ordered gasket set. Pressure should be good on pump.
The control valve bushing and spool seem to be the problem as noted by JMOR. I located a complete used lift cylinder. Will update as parts arrive and I install.
mvphoto36111.jpg
 
(quoted from post at 08:09:33 05/14/19)
(quoted from post at 19:12:59 05/12/19)
(quoted from post at 18:41:56 05/12/19) Attaching several diagrams showing what paths are open to flow and which are blocked at LIFT, HOLD, LOWER. Note that nothing ever blocks flow TO back pressure valve, but
unloader does block outflow from backpressure valve during LIFT. This by the way is what is NOT happening in your case, thus no lift. If you wish to discuss, my e-mail
is open on YT safe messenger, and I will reply to your e-mail and thru that method we can exchange phone numbers.
m8qhXIz.jpg

RPOy3Bu.jpg

ggQRezY.jpg

1eb4ulC.jpg

XlceFbC.jpg
Thanks JMOR, cant see the pics but I'm on my phone, will check when I get home. I couldn't see your email
.
I made mine available too in case you can see it. Will check that too when I get home on my PC
Thanks!
I will keep this updated until its repaired. Yesterday I attempted to do a pressure test with gauge but the gasket on pump started leaking. Pulled pump and ordered gasket set. Pressure should be good on pump.
The control valve bushing and spool seem to be the problem as noted by JMOR. I located a complete used lift cylinder. Will update as parts arrive and I install.
mvphoto36111.jpg
A celebration is in order! lift is working good, JMOR called it with the control bushing/spool, the previous owner installed the bushing backwards. i purchased a used lift cylinder and right away saw the issue with mine. put new o-rings and gaskets...time to paint it now
Thanks JMOR for your expertise!
 
one last thing, the above picture of the lift cylinder/control valve is my old one. you can see the clearance between the bushing and spool
 

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