Ive been chasing a noise in the hydraulic system for
awhile. Comes from the pump. Ive changed filters and
fluid a few times. But I still get a whine from the pump.
The hydraulics work fine, go up/down, have good power
and dont seem slow. This farmall 340 has the engine
driven pump. I hear the whine whenever the tractor is
running. If I operate a lever the noise stay. I hear the
safety pressure relief valve open at the end of a cylinder
stroke.
Ive checked for suction leaks by replacing hoses, clamps
and o rings at the pump to manifold connection. I even
split the tractor to replace a darn o ring inside it that
connects to the internal suction tube. Worked myself silly
checking for a suction leak so Im fairly sure that isnt the
cause of the pump noise.
I checked to make sure the valves were on the dual
setting and not anywhere in between.
I cleaned the regulator control orifice and even drilled it
out to .040. Checked the safety relief valve visually. To
check if the regulator valve ( unloader) was really
dumping pressure I re-routed the discharge hose to the
reservoir to a bucket. Got half a bucket of fluid in about
half a minute. So hears my question ( finally, right!) Can
the regulator valve be only dumping some but not all of
the fluid it should.?opening partially? I could drill ithe
orifice out a little more but if I go to big the system wont
go on demand and that thing costs$$$$.
awhile. Comes from the pump. Ive changed filters and
fluid a few times. But I still get a whine from the pump.
The hydraulics work fine, go up/down, have good power
and dont seem slow. This farmall 340 has the engine
driven pump. I hear the whine whenever the tractor is
running. If I operate a lever the noise stay. I hear the
safety pressure relief valve open at the end of a cylinder
stroke.
Ive checked for suction leaks by replacing hoses, clamps
and o rings at the pump to manifold connection. I even
split the tractor to replace a darn o ring inside it that
connects to the internal suction tube. Worked myself silly
checking for a suction leak so Im fairly sure that isnt the
cause of the pump noise.
I checked to make sure the valves were on the dual
setting and not anywhere in between.
I cleaned the regulator control orifice and even drilled it
out to .040. Checked the safety relief valve visually. To
check if the regulator valve ( unloader) was really
dumping pressure I re-routed the discharge hose to the
reservoir to a bucket. Got half a bucket of fluid in about
half a minute. So hears my question ( finally, right!) Can
the regulator valve be only dumping some but not all of
the fluid it should.?opening partially? I could drill ithe
orifice out a little more but if I go to big the system wont
go on demand and that thing costs$$$$.
