Ford 5000 losing hydraulic pressure when it heats up

Pomnut · Oct 22, 2013

Some background - ford 5000 losing all hydraulic pressure when it heats up. When the tractor is cold the the pto and linkage work fine but the linkage is sluggish. I got a mechanic to check pressure when tractor is cold and is all good. But as the tractor warms up the the linkage gets more sluggish and eventually stops lifting up and eventually the clutch stops engaging. ( auxiliary remotes stop working to).

I replaced the pump and filter about 2 months ago and it happened again so I took off top cover and made sure there were no leaks with hydraulic hose. While I was in there I replaced pto clutch break and pulled apart auxiliary plate( for the remotes) and replaced all o rings. But alas, I'm still losing pressure when the tractor and oil heats up. So I though maybe I got a bad pump.... So I bought a new one and replaced it again..... Still the problem occurred. One thing I have noticed is the pump gets extremely hot and starts making noise like its cavitating . So I open it up again and put a new o ring between pump and filter pick up. And still the problem occurs. The oil level is fine. Since pulling out the pump 3 times I have used different brands of hydraulic oil and even over filled it by a couple if litres.
I have spent a lot of time trying to get my grandpas tractor working just like it used too. I have fixed the gear box ,replaced the clutch and re conditioned the motor- but this problem is really annoying me. Any help would be greatly appreciated.

Soundguy · Oct 22, 2013

rickB is probably the man to answer this question.. if he doesn't see this post.. try to find him / pm him.

He's a nh mechanic / parts man and general all around smart fellow.

Pomnut · Oct 23, 2013

Thank you I will give him a try

oldnslo · Oct 23, 2013

First concern is why is the pump getting hot? Usually this is sign of operating under continuos pressure. If this is like our old 1956 5000 it has a gear pump which should not be under any pressure unless there is a valve malfunctioning. I don't recall if there is a way to check system pressure by tapping into the pump pressure line on that model. This would need to be done at the inlet of the directional valves. Check this pressure with no valves actuated. From memory it should be less than 400 PSI.

Soundguy · Oct 23, 2013

oldnslo said:
First concern is why is the pump getting hot? Usually this is sign of operating under continuos pressure. If this is like our old 1956 5000 it has a gear pump which should not be under any pressure unless there is a valve malfunctioning. I don't recall if there is a way to check system pressure by tapping into the pump pressure line on that model. This would need to be done at the inlet of the directional valves. Check this pressure with no valves actuated. From memory it should be less than 400 PSI.

there is no 5000 in 56.. 56 was near the very start of the ford 00 series.

the 5000 has a center section internal pump.

5000's were a 1965 creation

AGRIMAN · Oct 23, 2013

A few questions for clarification: The first pump you installed was it a used pump and the second one a brand new pump? Other than the pump, how hot is the rest of the hydraulic system getting? Does the rear remote valve get warm (normal operating temp) or do it get hot to the touch. Does your unit have dual power?

oldnslo · Oct 23, 2013

Soundguy said:
there is no 5000 in 56.. 56 was near the very start of the ford 00 series.

the 5000 has a center section internal pump.

5000's were a 1965 creation

dyslexia strikes again. It was a 65 not a 56...

RickB · Oct 23, 2013

Is the ASC selector set in the proper position? That would be the front knob of the two on the RH side of the lift cover, and it should be full 'in'.

Pomnut · Oct 24, 2013

The first and second pump were brand new. The the two hoses leading to and from my remotes get warm but I wouldn't say above operating temp. The pump itself gets very hot. I don't have any remotes on rear of tractor I have directed hoses to remotes to control front end loader. Note - I have not been using front loader and have removed to take weight off steering whole spraying. I hope that answers the questions. I apologise for my ignorance but what does it mean to " have dual power"

RickB · Oct 24, 2013

Pomnut said:
The first and second pump were brand new. The the two hoses leading to and from my remotes get warm but I wouldn't say above operating temp. The pump itself gets very hot. I don't have any remotes on rear of tractor I have directed hoses to remotes to control front end loader. Note - I have not been using front loader and have removed to take weight off steering whole spraying. I hope that answers the questions. I apologise for my ignorance but what does it mean to " have dual power"

Has the loader control valve been removed along with the loader? If so, are the pressure and return hoses to and from the valve plugged or looped together? If plugged, you have destroyed three pumps by not understanding the basics of open center hydraulics. Pump flow MUST have an unrestricted flow path back to tank.