determination of inlet- outlet on an unmarked closed center valve body

bemodoc · Mar 30, 2014

I am not totally positive but I believe it is a port to test the high pressure coming off the pump.

Tx Jim · Mar 31, 2014

bemodoc said:
I just looked at the pump area didn't see a relief valve Here is two pictures of the pump as good as I could get. thank you

No actual relief valve but pump has a stroke control valve(parts keys #24 & 25) that when operating correctly controls hyd pressure. Yes stand-by pressure can be checked at port where plug(parts key #5) is intended to go.

bemodoc · Mar 31, 2014

Thanks TX Jim for the clarification on the pump parts and what ports are which great info,great shot of the pump parts break down.I need to try and locate a service manual and parts manual for this 401b,the ones I have found are very expensive.Today I will see if I can hook up an air supply to the control valve on the 9250 backhoe and see if I can get this inlet high pressure and return line sorted out.Thanks for the info.