Case 1845c m91 tandem pump

[rico7467]

At idle charge pressure is 50psi at full rpm it is 300 psi. When you stroke the levers forward or backward at full rpm it drops from 300 to 200. It also does this with the ports capped off that go to the drive motors so that I could eliminate there being leakage in those. Any thoughts? Also my pressures on the M ports that go to the drive motors are 4500 psi

 

[GaryHoff]

Your piston pump is worn out. Sometimes all you will have to do is lap the valve plate.

 

[rico7467]

Your piston pump is worn out. Sometimes all you will have to do is lap the valve plate.

Came to find out on tear down that the previous installer of the charge pump installed it with the top pin an inch to the right of the hole. Hopefully this was causing my issues

 

[rico7467]

The pin is pushed so far into the aluminum housing I can't even remove it. I ordered a new pump and pin and will post the results once reinstalled

 

[kshansen]

The pin is pushed so far into the aluminum housing I can't even remove it. I ordered a new pump and pin and will post the results once reinstalled

Any chance you could drill a small hole from the opposite side, say a 1/8 inch and use a pin punch to push it back out? Would not have to line up perfect just close.