JD 650 hydraulics weak

gto7419 · Jan 2, 2016

Bought a JD 650 with loader last year. Ive noticed that the loader can lift about 400lbs to about 4 ft. Any additional weight or height leads to a very loud relief valve releasing pressure. From my reading, there are much smaller garden tractors that can lift more than that.

Any chance someone has a service manual so I can check hydraulic pressure/perform some basic maintenance?

If pressure is good and machine is in good condition, can the pressure be raised safely?

-Appreciate any help

beenthere · Jan 3, 2016

:welcome: to TBN

What are the records of hydro oil and filter changes? That would be my first move.
Second would be to get a copy of the service manual.
Third would be to make up a pressure gauge that you can plug into the various couplings.

Tx Jim · Jan 3, 2016

:welcome: to TBN
Ditto on testing pressure with a gauge to determine if it's in spec's.

gto7419 · Jan 3, 2016

Thanks for the warm welcome. Didn't get any maintenance history with the tractor.

Service manual would explain where to test pressure? Ive built a bunch of motors/cars, but never messed with hydraulics before.

Any idea where I can download the service manual?

Oldtink · Jan 3, 2016

The 650 has a 7cc hydraulic pump that will flow 4.4 gpm @ 2400 rpm. The main system relief valve opens at 2050 to 2300psi @ 1500 rpm per the spec in the tech manual.

gto7419 · Jan 16, 2016

I'm under the assumption that the relief is set by a screw on the 650? Any chance someone can scan the tech manual where the page is that shows the relief valve area?

Oldtink said:
The 650 has a 7cc hydraulic pump that will flow 4.4 gpm @ 2400 rpm. The main system relief valve opens at 2050 to 2300psi @ 1500 rpm per the spec in the tech manual.

gto7419 · Jan 16, 2016

I'm under the assumption that the relief is set by a screw on the 650? Any chance someone can scan the tech manual where the page is that shows the relief valve area?

Oldtink said:
The 650 has a 7cc hydraulic pump that will flow 4.4 gpm @ 2400 rpm. The main system relief valve opens at 2050 to 2300psi @ 1500 rpm per the spec in the tech manual.