1970 2520 tech. question

cantbeatadeere · Jun 30, 2015

I am changing the hyd. pump on my 2520 and there is a factory dimple on the face of the pump shaft....is that a timing mark of some sort?. also if anyone knows the ignition timing that would help as well....I have ordered the parts and tech manuals but was told it could be up to two weeks before I see them. thanks

beenthere · Jun 30, 2015

The info on the pump will be important, I'm thinking. Seems to be several pump mfg's used in this tractor series.

jd110 · Jun 30, 2015

The dimple on the hydraulic pump shaft signifies where the cam lobe in the pump is. It does not have any significance on assembly or installation of the pump. It is merely a reference point they use when machining the shaft. When you say ignition timing, I assume you have a gas model. The ignition timing should be at TDC at idle speed and 28 degrees advanced at wide open throttle.

cantbeatadeere · Jul 1, 2015

jd110 said:
The dimple on the hydraulic pump shaft signifies where the cam lobe in the pump is. It does not have any significance on assembly or installation of the pump. It is merely a reference point they use when machining the shaft. When you say ignition timing, I assume you have a gas model. The ignition timing should be at TDC at idle speed and 28 degrees advanced at wide open throttle.

............That's perfect...thank you.

Tx Jim · Jul 1, 2015

I hope you did sufficient diagnostics or tear down of pump that indicated pump required replacement because many pumps have been replaced to find out there was nothing wrong with pump that was replaced.

cantbeatadeere · Jul 1, 2015

Tx Jim said:
I hope you did sufficient diagnostics or tear down of pump that indicated pump required replacement because many pumps have been replaced to find out there was nothing wrong with pump that was replaced.

I am sure there have Jim, I am removing my 4 piston and installing a 8 piston pump to properly operate the loader I am going to install. my father had one on the farm years ago and the loader was a Dog until he put the 8 piston on it, she came alive after that. If anyone here is looking for a 4 piston that works perfectly with 1708 original hrs on it -- I have one.