Check / Relief Valve

[JD Ga]

I have a 1946 2N that will not hold a load up. I took off the RH inspection plate to see if I could tell where the leak was coming from but found nothing. Last fall I replaced the piston & O-ring and there's no sign it's coming fom up top either. It has noticable erratic motions while the PTO is engaged and trying to hold up the load.When the PTO is disengaged the load drops within seconds with no noticable sign of fluid from top or bubbling in the sump. I'm thinking maybe the Relief valve? The FO-4 shop manual says that it could be improper seating of the check valve portion of the relief valve. Any ideas on what it might be would be much appreciated.

 

[JMOR]

(quoted from post at 15:49:55 10/26/08) I have a 1946 2N that will not hold a load up. I took off the RH inspection plate to see if I could tell where the leak was coming from but found nothing. Last fall I replaced the piston & O-ring and there's no sign it's coming fom up top either. It has noticable erratic motions while the PTO is engaged and trying to hold up the load.When the PTO is disengaged the load drops within seconds with no noticable sign of fluid from top or bubbling in the sump. I'm thinking maybe the Relief valve? The FO-4 shop manual says that it could be improper seating of the check valve portion of the relief valve. Any ideas on what it might be would be much appreciated.

There are 8 places to look for leaks when lift will not hold up a load after pump stops. In addition you could have cracks in pump casting. The shaded area must hold pressure.