TC35d Pump shaft Seal

[horsekick]

New guy here. I have a TC35d that is blowing the hydraulic pump shaft seal. I have attached a pressure gauge to the rear remote and the system pressure reads 1900psi just above idle. I'm getting ready to remove the pump for the second time and need to figure out what is causing the seal to blow.

The tractor has the 16la loader with joystick control on it also. Is there a secondary relief valve in the loader control valve or does the main system relief valve cover everything? Could a worn pump cause it? The local dealer is happy to talk about bringing it to their shop for troubleshooting and repair but not what the main problem could be.

Any help or ideas what to look for will be greatly appreciated.
Thanks, Dave.

 

[Harry in Ky]

If the pump is properly assembled the area behind the shaft seal should be connected to the suction (inlet) side and should never be subjected to pressurized flow. As for relief valve(s), the only one I'm aware of is in the diverter manifold and should cover all systems except steering. There may possibly be another in the loader valve, but even so, the system pressure should not affect shaft seal life one way or the other. If you're having repeated seal failures, I'd be looking for something within the pump.