2755 hydraulic problem

[gfj]

loader will not move up or down 3pt will not lift. both will move very slow. neighbor was using tractor to put out round bales. put out 10 bales then tractor would not lift. steering works fine. full of oil. he knows nothing about mechanics says was working fine until it quit. could it be the front pump? hate when something goes wrong when someone else is using tractor.

 

[WTW]

Front pump is working if steering works. Same pump. Does the three point raise and lower? If it does, check that a hose from loader control valve didn't come uncoupled. from its connecting point?? A supply or return hose to the loader control valve comes uncoupled will stop loader functions, This is assuming you have an independent loader control valve that is connected to tractor hydraulic system. DW

 

[centash]

Priority valve sticking?

Ben

 

[Tx Jim]

Ditto what Ben stated about the priority valve(item 9) blocking flow/pressure to fel/scv. What type valve controls loader? If it's an ind fel control valve it's possible it could have blown an internal seal causing valve to revert back to open-center instead of closed-center. Simple test for blown seal is to disconnect fel ind valve return hose then aim open hose in hyd filler hole behind seat. With fel valve control lever in neutral,start engine & no oil should exit open valve return hose.

I also agree with WTW to check breakaway couplers to be sure they're connected correctly.

 

[Tx Jim]

Edit: for photo of priority valve I forgot to upload.

 

[gfj]

unhooked hoses for loader from tractor hyd. 3pt still comes up slow and jerky. we changed all oil and filters last month. could a filter have failed? loader does not go through scv is plumbed on the lever control box. loader has been on this tractor for 15 plus years.

 

[tim s]

The steering will work with low pressure.

 

[Tx Jim]

How long since hyd filter has been changed & sump screen(item 30) checked/cleaned? Hyd filter relief valve in photo in frt of screen could possibly be stuck open. With 3 pt raised,engine running look inside hyd filler hole behind seat for moving oil. If your tractor has hyd hi-lo &/or IPTO check hyd's with each control lever in both positions

 

[buickanddeere]

don't be one of those 10's of thousands of owners who guessed and changed the front pump without trouble shooting first.
Front pump will not pump if it is not supplied with oil.
Front pump will not be able to keep up with flow if the loader joystick valve has blown into open center mode.
Where exactly does the loader supply and loader return hose connect to the tractor ?

 

[tim s]

It takes about 1750psi to open the priority valve..This system is ornery to diagnose..to say the least...

 

[WTW]

Not really, Just another system.

 

[WTW]

Sounds like main hydraulic pump pressure has fallen below priority valve pressure. This will cause priority valve to restrict / close / shut of flow to rear / secondary functions. Check pump stall pressure and see if it near the 2000-2200 psi? If by chance pump has a de-stroking screw on it, de-stroke pump and turn back on a couple times to see if stroke control valve is stuck or has possible small piece of debris caught in it. De-stroking screw located on pump cover under air cleaner ahead of radiator, with roll pin for handle cross ways in screw on top edge of hydraulic pump cover. loosen and turn screw in until you fell it touch valve then give it 1/4 turn to push valve down which will shut pump off, then back it back out again. Do this a couple of times with engine running. If you do not find this screw it may not ever had one. DW

 

[Tx Jim]

2755 in addition to hyd pump destroking screw(item 1) that WTW referred to it could alternately have a destroking screw(item 40) that requires a wrench to turn.An electrical operated DS valve was also offered.