I have a d39px-21a had no charge pressure. got pumps rebuilt...have 440-500 psi charge pressure now.. when lever is picked up alarm sounds and low charege pressure light comes on. manual gauge shows 500 psi. do not have parking brake release pressure, does have new solenoid valve still no release of brake. new pressure switch installed as well........any advise?:Banghead
Blank off left and right park brake port at the motor. See if problem persists, if it doesn't remove the left then check again and so on.. I have seen the seals go bad in short time as well as the brake plates crack. Good luck!
Thanks for the info will advise of findings