On Thu, 12 Jun 2014 19:30:23 -0500, Ignoramus32163
wrote:

On 2014-06-12, wrote:
On Thu, 12 Jun 2014 14:49:13 -0500, Ignoramus32163
wrote:

Lower power output of pumps does happen due to wear. Pay to have it
rebuilt.
If oil is leaking past the gears then the pressure should drop, right?
Danfoss, who make hydraulic gear pumps agree with me. They say if the
pump pressure plates wear the pressure output will bw lower. And lower
pressure is the problem I am having.

I recall reading a certain talmudic tome on hydraulics and they say
that neither having a high pressure, or high flow, alone, indicates
that the pump is not worn. Only loss of "power", which is pressure
multiplied by flow, is a good indicator that the pump is worn.

You have a hydraulic pressure gauge on your machine, right? Easy to
add one temporarily and see what the pressure does when the pump is
pumping a lot of fluid.

i
Some pumps, when worn, will not even produce rated pressure against a
closed valve, much less into a functioning system.