Weak loader on kubota b7200 with 1640 loader

[fatjay]

I'm trying to figure out the location of relief spring on the valve and what kind of shims I need. I think I have found where the spring is, on the top. But there's also one on the bottom.

My primary issue is break out force on the curl, it doesn't do what it should. It's a 1986 tractor, so I'm assuming the spring is tired. I see the same tractor that can lift the front wheels off the ground with the bucket. Mine can't even begin to do it, I just hear fluid passing through the relief.

Any advice is appreciated.

 

[bdhsfz6]

I had a 1980 B7100HST with 1640 FEL that experienced a low hydraulic pressure issue. The problem turned out to be the 3pt hitch lever was left in the extreme up position, causing the hyd. system to go into partial bypass. Check that first.

There are two different methods used to power the FEL on the B7100. The first uses the internal tractor hydraulics and the second uses an external hyd. pump connected to the engine driveshaft on the front of the tractor, mounted on the FEL frame, just below the radiator.

My B7100 used the second method and the hyd. relief valve was located under this cap:

Some valves have a set screw to adjust the pressure, and others require a shim under the spring. Mine needed the shim which I made from a washer. I used a standard washer and ground it down to get the pressure I wanted. BE CAREFUL not to set the pressure too high! I believe the max on my tractor was 1800 PSI. It could be different if yours uses internal hydraulics.

Eventually, the external pump on my tractor wore out. Shimming the valve did no good and I had to rebuild the pump.

Hope this helps.

 

[ptsg]

Before messing with any shims and potentially blow the pump, get a pressure gauge and find out what pressure it's putting out. After that, you can troubleshoot some more stuff before throwing shims at it.

 

[Dave M7040]

What model of B7200 do you have...... type of transmission and is it 4WD
PTSG's advice should be followed!
Look at the front of your engine and see if there is a hydraulic pump being driven from lower crank pulley.
Dave M7040