Case 9020b bogging engine when using certain functions.

[blue66tang]

Hi all. I have a issue with my 9020b. The machine works real well for a couple hours or until the hyd oil gets good and warm. Then certain functions will start to bog the machine horribly. The boom up will bog it, as well as the drive wheels on the logging processor head. The boom up doesn't bother me as much, but processing head becomes almost useless cause it will no longer have the power to strip branches off. I am convinced it is a machine and not a processor head problem. I am also convinced it is not an engine problem. I think it is something in the hyd system. Anybody have any know how on this machine?

 

[blue66tang]

Anybody? Somebody has had to have had a similar issue.

 

[GaryHoff]

From your last post, you said that the machine was bogging down with the controls in neutral.
If your pump is staying stroked on with no functions selected, then your negative control pressure will be too high ports (P11 and P21).
Measure your negative control pressure.

 

[GaryHoff]

 

[blue66tang]

Thanks. I will check that out! What actually destrokes the pumps? It doesn't always stick and lug the motor permanently. I can use a function, it bogs the motor, I can then release the function and it will continue to bog for a second or two afterwords. It's not the motor just taking the time to catch back up. It's a definite valve/solenoid sticking and then releasing.