still have hydraulic problems

[svenandersen]

My JD 2640 hydrualics are still giving me fits. The loader is slow and the lines chatter a lot. The mechanic thinks the intake for the transmission pump is cracked and we've overfilled it a bit which hasn't helped. We changed the filter and cleaned the screen. If you work the bucket or 3-point up and down a lot, it'll finally prime and start working, but only for a little while. Seems to be sucking air. Any other ideas?

 

[buickanddeere]

Sounds like some major fundamental flaw that would never be suspected and it looks good but is a fault.
Has somebody had this tractor apart and didn't assemble something properly?
Is there a transmission plugged filter bypass valve stuck?Is there a transmission relief valve opening below 150psi?
Is oil bleeding off on a failed pto brake or something? Try the loader with the pto engaged?
Is the trans pump weak or a failed/cracked/loose pump suction line?
It has to be some simple but well camouflaged problem.

 

[Tx Jim]

svenandersen
Is your mechanic very knowledgeable on JD closed center hyd systems??????????????????????

If it's sucking air then the hyd oil should be foamy. Is the hyd oil foamy?? If I thought trans pump supply was sucking air I remove rockshaft housing and block off RS supply oil then run tractor and have a look.

Did you check for spraying hyd oil in hyd filler hole with 3pt raised & engine running??

Did you disconnect loader control valve and with both valve levers in neutral,engine running and no oil flows out of return hose???

IF tractor has hyd pto has operating pressures been checked??

Has stand-by pressure been checked and is it set at 2250-2350 psi?????

 

[cannonball]

what transmission does this tractor have..does it have reverser..

 

[svenandersen]

It has 4 gear, hi lo range transmission with hi lo power shift.

 

[svenandersen]

I will discuss these comments onto the mechanic and let you know.
Sven

 

[svenandersen]

The fluid actually does look foamy when I've hooked up implements and some has dripped out.BTW the implements barely raise. I did not see oil spray in the filler hole. I'll check on your other questions

 

[Tx Jim]

(quoted from post at 09:46:27 08/13/12) It has 4 gear, hi lo range transmission with hi lo power shift.

Besides having hyd hi-lo does it also have hyd pto?? Both options have tubes that have a history of cracking/leaking causing hyd nightmares.

 

[buickanddeere]

The mechanic maybe a great guy and modest in price
but......As TxJim says, it's time to take the tractor to a JD pro,
takes less time, pay less $$$ in the long run and have a
working tractor.

 

[svenandersen]

Hmm, I guess I don't know. I assume it is mechanical.

 

[Tx Jim]

(quoted from post at 15:06:51 08/13/12) Hmm, I guess I don't know. I assume it is mechanical.

Mechanical what?? If your tractor has hyd pto it will have a control lever in between the 2 gearshift levers.

 

[Tx Jim]

(quoted from post at 13:45:27 08/13/12) The mechanic maybe a great guy and modest in price
but......As TxJim says, it's time to take the tractor to a JD pro,
takes less time, pay less $$$ in the long run and have a
working tractor.

I agree with b&d aka Mr T that JD closed-center hyd systems REQUIRES a very knowledgeable person to correctly/successfully diagnose their problems.

 

[svenandersen]

Yes, you are correct. Sorry for the confusion.
I called the JD shop and you guys are spot on.