4620 John Deere tractor has hydraulic issues

[Leo Whitten]

I've been working on repairing this tractor for almost a month.
Every time I think I have it fixed, another hydraulic problem pops
up. First it was the hoses and pipes, then the control valve, now
it looks like the transmission pump needs to be replaced along
with the hydraulic pump. I know this tractor is nearly as old as I am,
but repairs are still less expensive than buying a new one. The
worst symptom is that things that require hydraulic pressure to
function don't seem to be getting enough pressure. I've already
split the tractor to rebuild/replace clutch/PTO stuff--what a project!!!
I've also rebuilt the brakes, thank goodness that works!

Can we re-split the tractor without loosing the pilot bearing in the works???

Any suggestions or information would really help, thank you!!!

 

[Tx Jim]

Which trans does this tractor have? If tractor has a Syncro-range trans R&R of trans pump requires no splitting of tractor.Many front hyd pumps have been replaced when in reality the front hyd pumps were GOOD. Have you flow & pressure tested either pump? Have you checked/cleaned hyd oil sump screen?

 

[Leo Whitten]

Thanks for the great info! It does have the Syncro-range trans, so no splitting is the best news of all!
I did a rebuild on the front pump when we replaced the control valve, it seems functional now. I also
removed the hose from the tube coming out of the top of the trans, and started the engine, no oil
squirted out! That seems to indicate your assessment is correct, on the hyd oil sump screen. It's a
work in progress, I'll keep you posted.

 

[Tx Jim]

Place a container under opening,remove hyd filter, crank engine over for 30 seconds and see how much oil you get. To R&R trans pump on SR trans one needs to raise rockshaft housing to access pump.