401 C hydraulic pump..??

[Fordcummins83]

Hey everyone! I have a JD 401c tractor, everything works great when it's cold, but the more it starts warming up the more it starts acting up and shuttering as if its sucking air, do you think this problem would be in my hydraulic pump? I was going to remove it but I want to check and make sure what you guys think first.. Any help would be greatly appreciated!!

 

[Tx Jim]

Several things can contribute to hyd problems on a tractor such as yours with a "closed-center" hyd system. Some diagnostics including pressure checks are in order before pump removal. Frt pump could be not getting sufficient oil supply from trans pump or possible high pressure internal leak depleting frt hyd output.

 

[Fordcummins83]

What should my pressures be and at what locations? Are there o-rings in the front pump that could have failed? The 3- point works fine all day long and the steering does too, just the loader shudders once it warms up

 

[Tx Jim]

If 3pt & steering work then I'd recommend checking stand-by pressure at the top of the hyd pump. PSI should be 2250-2350 psi. How long since hyd filters were changed and sump screen cleaned??

 

[Fordcummins83]

Probably been awhile, I really don't have the tools to be checking psi but is there a way I can check gpm or so on that?

 

[Tx Jim]

GPM can be checked with a flowrater. A 3000 psi gauge isn't very expensive about $30

 

[Fordcummins83]

Ok, is there a port in the pump I can put it in?

 

[Tx Jim]

Remove parts key #7 and install gauge. Here's the spec's on parts key #7
Thread Size 0.562 IN
TPI (Threads Per Inch) 18
Thread Length 0.394 IN
Length 0.689 IN
Diameter 0.00 IN
Hex Size 0.688 IN

 

[ghenges]

Have you checked the charge pump?
------------------------------------------------------
Some photos may help.
Your pump is the same, except your charge pump is in your transmission housing (I believe)

Right Side

Left Side

TOP

BOTTOM

FRONT

BACK

 

[Zebrafive]

Remove parts key #7 and install gauge. Here's the spec's on parts key #7
Thread Size 0.562 IN
TPI (Threads Per Inch) 18
Thread Length 0.394 IN
Length 0.689 IN
Diameter 0.00 IN
Hex Size 0.688 IN

The thread size per your specs will be SAE 6. Also called ORB (O Ring Boss)# 6. The 6 is for 6/16" or 3/8"