1700 Hydraulic Problem

[andreww]

I have low hydraulic pressure and have changed the fluid and cleaned the filter. I have checked the system relief valve pressure and according to my manual it is supposed to have 2065 to 2205 psi at the cylinder head by the flow control knob. I am only reading about 800 psi. Any ideas on what I should check or what I should do? Original problem is the brush hog and front end loader both do not raise as they should.

 

[bumperm]

It can only be one of a couple of things I'd think. Either you have a relief valve stuck open or some other part that is broken and bypassing fluid back to the reservoir, or your hydraulic pump is worn or broken.

Did you take the relief valve apart to check it? On my tractor, if I hook up a shop vac to the hydraulic oil filler, there's only a couple of drops of fluid lost when removing the relief valve.

 

[JC-jetro]

You ndeed to inspect the poppet valve to make sure the valve is nice and conical and not damaged causing leak by. The spring stiffness is adjustable. Turning the nut clockwise is more pressure and CCW lowers the pressure. While you have the tractor running and oil fled pressure is connected. slowly turn CW to see if pressure goes up.

You need to tale the cap off at the end of the Relief device to expose the nut for adjustment. The 2300 psi for 1700 as the rated PTO speed of 450 around 2400 or so RPM. I think I had my tractor at about 1500 rpm and developed psi was less than 2300 psi.

jc

PS. Pressure developed by hyd is directly proportional with the engine RPM. psi developed on my rig was around 1500 rpm.