B1750 - 3 Point Hitch only works after jiggling loader control valve

[Titan17]

Hi all. Been a while since last posting. As usual you hear from some people only when they have problems; I'm one of them.
After 3 years with no tractor I'm finally moving to our previously rented farm property.
I bought from a friend an old B1750 D w/fel and RFM for property maintenance. Only 621 original hours near perfect condition and everything functions as it should except 3PH.
The loader control needs to be jiggled then it lifts fine. It lowers fine also
I guess it's an OC spool with float detent. I cleaned, replaced ball and reassembled detent. Tractor sat for long time and it only occurs occasionally but since I'm mowing with a rear RFM I'd like it to be dependable.
Anyone have insight on this issue?? Maybe disassemble to clean spool, maybe some use will fix.
For machines that sat for long periods - I've used them a bit and problems self correct. This might be the case.
Fluids changed, screen cleaned, loader works fine.
Any and all comments appreciated.

 

[TheOldHokie]

Hi all. Been a while since last posting. As usual you hear from some people only when they have problems; I'm one of them.
After 3 years with no tractor I'm finally moving to our previously rented farm property.
I bought from a friend an old B1750 D w/fel and RFM for property maintenance. Only 621 original hours near perfect condition and everything functions as it should except 3PH.
The loader control needs to be jiggled then it lifts fine. It lowers fine also
I guess it's an OC spool with float detent. I cleaned, replaced ball and reassembled detent. Tractor sat for long time and it only occurs occasionally but since I'm mowing with a rear RFM I'd like it to be dependable.
Anyone have insight on this issue?? Maybe disassemble to clean spool, maybe some use will fix.
For machines that sat for long periods - I've used them a bit and problems self correct. This might be the case.
Fluids changed, screen cleaned, loader works fine.
Any and all comments appreciated.

Sounds like one or more of the spools in the loader valve is sticking. Could be as simple as the joystick linkage needs a little lubrication.

Dan

 

[Titan17]

Sounds like one or more of the spools in the loader valve is sticking. Could be as simple as the joystick linkage needs a little lubrication.

Dan

Working on it now. Everything is lubed and smooth. Pulled the detent cap off. Everything appears fine.
It's only occasionally it happens. Works fine when loader valve is on bypass.
When it happens I hear a slight load on hydraulic pump even when loader is in float.

 

[TheOldHokie]

Working on it now. Everything is lubed and smooth. Pulled the detent cap off. Everything appears fine.
It's only occasionally it happens. Works fine when loader valve is on bypass.
When it happens I hear a slight load on hydraulic pump even when loader is in float.

What does "when valve is on bypass" mean? And I am not clear what float has to do with this. Its a two spool valve. Only one needs to be blocking power beyond to cause your issue.

Dan

 

[Titan17]

What does "when valve is on bypass" mean? And I am not clear what float has to do with this. Its a two spool valve. Only one needs to be blocking power beyond to cause your issue.

Dan

When I bypass the loader by turning lever 90° to take loader off the circuit the 3ph works every time so I know it's not in the 3ph control valve.
It happens only when I use the loader and it comes out of the float position. I don't think the spool is returning to it's open center position. Hopefully you or someone can confirm. I took every line off before diverter valve and checked quick disconnects for blockage. I'll keep using it to see if improves or try anything someone throws at me for suggestions. Next pull spool out???

 

[TheOldHokie]

When I bypass the loader by turning lever 90° to take loader off the circuit the 3ph works every time so I know it's not in the 3ph control valve.
It happens only when I use the loader and it comes out of the float position. I don't think the spool is returning to it's open center position. Hopefully you or someone can confirm. I took every line off before diverter valve and checked quick disconnects for blockage. I'll keep using it to see if improves or try anything someone throws at me for suggestions. Next pull spool out???

OK - the selector valve on the hydraulic outlet block is whats in "bypass".

My diagnosis has not changed. One of the spools in the loader valve is not returning to center. That blocks the power beyond port on the loader valve and the pump unloads to tank via the tank return on the loader valve. The only question is why is the loader vslve sticking.

Dan

 

[Titan17]

OK - the selector valve on the hydraulic outlet block is whats in "bypass".

My diagnosis has not changed. One of the spools in the loader valve is not returning to center. That blocks the power beyond port on the loader valve and the pump unloads to tank via the tank return on the loader valve. The only question is why is the loader vslve sticking.

Dan

Should I take it apart and clean?? What would you do and I'll follow your advice. Seems like you've been down this road.

 

[TheOldHokie]

Should I take it apart and clean?? What would you do and I'll follow your advice. Seems like you've been down this road.

I have an older model (B7200) that uses that same (or very similar) selector valve.

If it were me I would go to my tool chest, pull out a 3000 PSI test gauge, and check pump pressure at that block. If it tests good I would move down the supply line checking pressure until I found the a point were pressure was lost. Then I would try to find the source of the pressure loss which is somewhere between the last good test point and the failed point.

Dan

 

[Titan17]

Should I take it apart and clean?? What would you do and I'll follow your advice. Seems like you've been down this road.

I appreciate you jumping right on this. Sometimes posts just sit for days before someone responds.
I have to start mowing and grading the driveway the day this is done.

I have an older model (B7200) that uses that same (or very similar) selector valve.

If it were me I would go to my tool chest, pull out a 3000 PSI test gauge, and check pump pressure at that block. If it tests good I would move down the supply line checking pressure until I found the a point were pressure was lost. Then I would try to find the source of the pressure loss which is somewhere between the last good test point and the failed point.

Dan

I don't have a pressure test setup but it's good to have. Tractor supply has everything I need I'll figure out the plumbing and pick up tonight.
But I think your first suggestion was right on. Sticking spool. Will test tomorrow. And most likely check the spool. Will post back tomorrow.

 

[Titan17]

I appreciate you jumping right on this. Sometimes posts just sit for days before someone responds.
I have to start mowing and grading the driveway the day this is done.

I don't have a pressure test setup but it's good to have. Tractor supply has everything I need I'll figure out the plumbing and pick up tonight.
But I think your first suggestion was right on. Sticking spool. Will test tomorrow. And most likely check the spool. Will post back tomorrow.

.
Here's a pic of the tractor. It looks 3 years old not 30

 

[TheOldHokie]

I appreciate you jumping right on this. Sometimes posts just sit for days before someone responds.
I have to start mowing and grading the driveway the day this is done.

I don't have a pressure test setup but it's good to have. Tractor supply has everything I need I'll figure out the plumbing and pick up tonight.
But I think your first suggestion was right on. Sticking spool. Will test tomorrow. And most likely check the spool. Will post back tomorrow.

My apologies - I meant to post that to a different thread. It was not meant for your problem.

Dan

 

[Titan17]

My apologies - I meant to post that to a different thread. It was not meant for your problem.

Dan

 

[Titan17]

I took spool out and cleaned/scotch bright. I checked that it's running true. It seems much better. Happens maybe once every dozen times. Dealer recommended a detent kit Part# 70050-01559. Service stated that it will center the spool. I will report back.

 

[Titan17]

Problem seems to be solved. Used 3 hrs yesterday. Cycled the 3ph maybe 30 times and happened 1 time. I expect it to get better with use. If not I'll buy detent kit.
T. Y. Oldhokie for recommendations.

 

[TheOldHokie]

Problem seems to be solved. Used 3 hrs yesterday. Cycled the 3ph maybe 30 times and happened 1 time. I expect it to get better with use. If not I'll buy detent kit.
T. Y. Oldhokie for recommendations.

Quite welcome and glad it worked for you. Careful with the ScotchBrite. The spool clearance in the body is the only pressure seal and its a a sub-thousandth tolerance. Get too aggressive and you may wind up trading sticking for leakdown problems.

I dont know what the dealer wants for that detent kit but if your problem continues a modern upgraded valve is only $150.

Dan

 

[Titan17]

Quite welcome and glad it worked for you. Careful with the ScotchBrite. The spool clearance in the body is the only pressure seal and its a a sub-thousandth tolerance. Get too aggressive and you may wind up trading sticking for leakdown problems.

I dont know what the dealer wants for that detent kit but if your problem continues a modern upgraded valve is only $150.

Dan

Thks. For all the tips. I used a green scotch bright not aggressive red; barely barely removes the crud let alone any spool material.
The detent kit is $66. If I could bother you with 1 more reply, what would you use for a modern valve??

 

[TheOldHokie]

Thks. For all the tips. I used a green scotch bright not aggressive red; barely barely removes the crud let alone any spool material.
The detent kit is $66. If I could bother you with 1 more reply, what would you use for a modern valve??

Right now the best deal going is probably this valve from Summit. I purchased one from a different seller for my B7200 but have yet to install it. Adds regen to the dump function and has a much nicer joystick linkage.

Dan

Brand Hydraulics Joystick Loader Valve 2 Spool w/ Float

Brand Hydraulics Joystick Loader Valve 2 Spool w/ Float can add two functions. Valve has 10 GPM capacity. Free Shipping!

summit-hydraulics.com

 

[Titan17]

Right now the best deal going is probably this valve from Summit. I purchased one from a different seller for my B7200 but have yet to install it. Adds regen to the dump function and has a much nicer joystick linkage.

Dan

Brand Hydraulics Joystick Loader Valve 2 Spool w/ Float

Brand Hydraulics Joystick Loader Valve 2 Spool w/ Float can add two functions. Valve has 10 GPM capacity. Free Shipping!

summit-hydraulics.com

Thank you.
I used summit few years ago for 3rd function kit. Any more probs and that's the way I'm going. These are kinda sloppy setups even when new.
Jim
Jim.