pump or valve problem?

[jes230]

My 1979 JD 410 lost bucket/hoe hydraulic pressure both at at the same time while it was moving, will still drive but drags the bucket/hoe. There was not a loss of fluid when this happened. I don't have a manual so can somebody tell me if the problem is caused by a pump or valve?

 

[Tx Jim]

1st thing to do is check front hyd pump pump drive coupler to be sure it's not stripped out and hyd pump shaft is turning while engine is turning. Then it's possible stroke control valve in frt hyd pump has failed. I'd suggest to get and install a 3000 # gauge to check stand-by pressure which I think is 2500 psi.