310a backhoe weak and slow hydraulics

[onalaskahoe]

I did a pressure test on the backhoe today and the results or.

the lower test port on the right side looking from the driver seat.

At idle 0 psi at 1000rpm 0 psi at 2000rpm 0 psi


The upper test port.
At idle 250 psi At 1000rpm 1000 psi At 2000 rpm 1200 psi. When i activate any cylinders it drops to about 900 psi.

The trans is working great, at idle I can put into drive and the trans will hookup and drive and it will stall the tractor in all gears, so there is no slipping from the clutch.



My question now is. could i have something blocking the flow into the pump?

Could the pump or stroke control valve be assembled incorrectly?

Hello all
My John Deere 310A backhoe has slow and weak hydraulics, the machine moves fine in both forward and reverse, and the steering is pulsy. Even with the RPM up over 2100 I still have slow and weak hydraulics. I have done the following and I will list the results.

1) Replaced the Hydraulic filter.
2) Replaced the Trans filter.
3) Removed and cleaned and replaced the Hydraulic intake screen. (There was very little dirt on the screen).
4) Removed the Hydraulic filter mount and checked the relief valve, it looked good.
5) Checked radial pump and pistons look great and o-rings look good and closed back up.
6) Replaced STROKE control valve.
7) Replaced system fluid with new fluid.

 

[Roy Suomi]

Did you do the reverser control valve test I told you about ?? Gauge into test port bottom rear cover , pointing straight down..Read the pressures from idle to wide open..there should not be more than 20 to 35 lbs variance..Any more than that indicates filter relief valve is held partially open with very small piece of crap..In many cases , you can hardly see the crap thats holding the valve poppit from seating...You have to have adequate charge pressure to make the hydraulic pump work correctly..What's the lower pump plug reading while you're testing the main pump pressure ??....The lower one is charge pressure....

 

[onalaskahoe]

the lower test port on the right side looking from the driver seat.

At idle 0 psi at 1000rpm 0 psi at 2000rpm 0 psi

 

[onalaskahoe]

Here is what I have:
Capped of output line from pump after the tee for the power steering and started backhoe, pump pressure went right up to 2600psi. Stopped motor and backed off stroke pressure control valve, restart pressure went right to 1100psi adjusted stroke pressure valve in to set at 2000psi at idle, rpm up to 2000rpm pressure stayed at 2000psi, turn streering left and right pressure would drop to about 1700 1800psi and come right back to 2000 when streering action stopped.
reconnected output line and capped off backhoe after priority valve. idle pressure 150- 200psi 2000rpm pressure at about 1000-1100psi.
reconnected backhoe and capped off output line from priority valve to loader. idle pressure 150- 200psi 2000rpm pressure at about 1000-1100psi.

is it possible that the priority valve could be the reason of my pressure loss?


What do you think.??