AC 5045 hydraulic problems

[Tom Smuts]

Hello,

I have an AC 5045 tractor, bought new in 1980. The hydraulics are not working properly. I have changed fluid, cleaned filter, no metal on the filter magnet, pulled pipe from tractor transmission belly to the pump to make sure it was not clogged, etc. At present fluid level is overfill to make sure plenty of fluid there.

Symptons: It will raise scraper blade at snails pace, meanwhile there is a screeching noise coming from somewhere on the tractor while lifting. Once lifted the noise stops if you push control arm slightly downward. Not able to determine where due to noise traveling thu piping, etc.
Installed pressure gage on external outlet and reads 2000 psi then drops off and picks up again to 2000. This may be due to release of the over pressure valve.

Log splitter hooked to externals does the same thing, moves at snails pace with screeching noise.

It would seem to me that if the pump puts out 2000 psi then pump ok and that some blockage somewhere is causing the screeching noise.

Any thought on were/how to proceed will be appreciated.

Thanks,

Tom

 

[J_J]

It sounds like a relief valve is letting off pressure.

If your hyd system is open center hyd system, fluid should flow through all valves to tank.

What pressure do you show with valves in neutral?

How did you connect the log splitter?

Do you leave the 3pt lever in neutral?

 

[Tom Smuts]

Yes, the system is open centered. With both lift and external controls in neutral, no pressure reading at the external coupling. Pressure only when the external lever is engaged.

I took off the pressure relief valve and looked for anything unusual. Nothing noted, however no way to check if it is releasing prematurely. There is the same kind of relief valve on the other pressure pump for hydraulic steering. I have thought about switching them, but not sure if it is the same pressure.

Thanks,

Tom