B2400 intermitent hydraulic problem

[B2400 owner]

Hello all, hope your doing well. I recently bought a burned up B2400 that I have about finished rebuilding. Everything behind the firewall to the seat that was plastic melted and as you can imagine it has been an interesting project.
Now that everything is back together and I am using the tractor, I have found that the power steering is dead and the three point hitch, after a couple minutes of use, is dead. I can sometimes get the hitch to raise by upping the engine RPM's, but not very often. Usually the hitch works fine at first when the tractor is first started.
All the line have been flushed and filters replaced(for obvious reasons).I did have to take the top of the power steering assembly off to replace the top shaft seal and the two o-rings between the cover that had melted.
One of the service techs where I by my parts said it could be the flow divider on the pump. I have checked for leaks in the suction hose and have not found any.

Any thoughts or suggestions would be appreciated.
Thanks,

Brad

Oops, I think I may have messed up when I put the power steering gearbox back together. I think it's operating at relief. Will know when it's back together.

 

[kennyd]

Welcome to TBN

I would suspect the o-rings and/or seals in the rockshaft valve (the lever that controls the 3PH) are toasted, You will also need to check and verify the PRV (pressure relief valve) setting with a pressure gauge.

 

[B2400 owner]

Thanks for the welcome.
After putting the gearbox back together(hopefully correctly)and hooking the hoses back up, I still have no power steering, but the three point hitch worked perfectly. After a few times raising and lowering the hitch, it still quits working until the engine is reved.
I also noticed the pipe going to the power steering from the priority valve is vibrating at a high pitch with the power steering box whining a bit.
Any thoughts? Pump, priority valve, power steering, or hitch?

Thanks,
Brad

 

[Farmerford]

Brad:

Here are some possibilities:

1. The pump may have elastomer seals between the wear plates and the pumb housing ends that were damaged by the heat, that would reduce pump output. It might be barely adequate to lift the TPH when the oil is cold, but the oil thins significantly as it warms up and then the pressure drops. Your shop and parts manuals should tell you if there is anything other that steel and aluminum inside the pump.

2. The priority flow divider probably depends on a precisely calibrated spring to divide the flow properly. The heat could have weakened the spring so that is is not sending much oil to the steering valve.

3. In addition to the seals in the TPH valve, there is a sealing ring around the TPH ram that is often made of plastic and could have been damaged by the heat.

You will probably need special fittings to check pump output pressure prior to the priority flow valve. But a teardown and physical inspection of the pump should answer your questions about the pump.

The shop manual probably gives specs for the length of the priority flow control spring at a specified load.

Defects in the seals and o-rings in the TPH should also appear in a visible inspection.

Good luck

 

[B2400 owner]

Hey guys, thanks for your input. I think my next step is going to be to tear down the hydraulic pump and priority valve. The pump and valve themselves didn't get to hot but after reading the suggestions, I'm thinking the heat from the suction hose leading to the pump being on fire farther back in the system very well could have toasted the seals in the pump or valve.
I'm thinking this would be a good (cheap) first step, and then go from there.

I owned a B21 of the same year model for years and still have the the shop manual for it. Looks like most of the parts are the same except the transmission. I know the motor, pump, and valve are the same.

Thanks again for your help.
Brad

 

[jenkinsph]

I would check the hydraulic pump before the priority valve, reasoning that the 3ph works until the oil is warmed up. If the pump cannot develop enough pressure then the priority valve sends oil to the steering (maybe brakes) only.

I would also pay particular attention to the pump inlet screen too. Since you have had a chance to run it for awhile something my have moved down the lines and is blocking the inlet.

My dad bought a used 4020 diesel years ago with similar issues, the dealer was having problems getting it fixed and was under new management. We bought the tractor and the dealer threw in a new transmision pump which I installed only to find the problem was still there. Finally found the culprit to be an inline filter screen on the pump was stopped up, a $15 part. Bought the tractor for $5000 and was worth twice that with the fix.