Sunstrand_ Implement Hydraulic Pressure

[mike melillo]

2182 with Haban Plow

Operational issue:
The hydraulics are very slow but they seem to have adequate power. I'd like more power but more so faster action. Also, the spool valves are sticking at full travel. I'm certain its not the levers binding, or the springs being weak since I have replaced the springs with new ones. They do not hangup with the engine off.

Test Issue:
I tested for implement hydraulic pressure at the port referenced in the U15 service manual which says the pressure should be 700-800PSI.The manual doesn't clarify the throttle position for the implement port, only the charge pump.

When I test from idle to full throttle its about 150-200 PSI, and it doesn't change with engine speed, only if I actuate the spool vale. When I do that and as the plow blade is lifting the pressure hovers around 500 PSI. When the ram reaches full stroke it pegs to 1000 PSI. So it appears to be operating at 150 no load, 500 under a load and dumping at 1000.

Questions:
Why is it only reading 150 with no load, and why is it increasing under a load? I'm testing at the port, not the valve.

If the test procedure was correct and the pressure is only 500, would you think the charge pump is going bad, or is something else off?

If its dumping at 1000 then the pressure relief is slightly high. Do you think this may be causing the spool valves to stick?

Also, are there any tricks to bump this up and or speed up the action without increasing the dump limit?

Mike