M7040 Lowering speed adjusting valve

[chance250]

Anyone has an issue not being able to turn the lower speed knob behind the seat? My 3pt hitch will pick up and lower bit it's a little slow lowering. it used to work fine.
My loader and bush hog will pulsate every once in a while at idle setting still. Don't know if that's a problem.
I have sprayed penetrating oil where the rod goes in the top of the case still won't budge. Any idea's?
Thanks

 

[Fallon]

Pulsing indicates a mis-adjusted 3pt feedback rod or a leak in the 3pt valve/cylinders.

 

[chance250]

Thanks Fallon,
Must be miss-adjusted feedback I don't see any leaks. The only other issue I can't seem to fix the the lowering speed the knob behind the seat will not turn at all I have sprayed PB oil where it goes into the case on the rear of the tractor still froze tight

 

[Tx Jim]

chance250
Welcome to TBN
Pulsating 3 pt usually indicates the control valve is leaking internally or more than likely the rockshaft piston seal is leaking. Are you positive both loader & 3 pt are pulsating or just 3 pt?

 

[Dave M7040]

Thanks Fallon,
Must be miss-adjusted feedback I don't see any leaks. The only other issue I can't seem to fix the the lowering speed the knob behind the seat will not turn at all I have sprayed PB oil where it goes into the case on the rear of the tractor still froze tight

Sent you a PM
Dave M7040

 

[Fallon]

The leaks would likely be internal.

As oil leaks out of the 3pt however it's getting out, the 3pt drops. When it drops enough for the feedback rod to bump the valve, it raises back up. Repeat.

 

[Dave M7040]

The leaks would likely be internal.

As oil leaks out of the 3pt however it's getting out, the 3pt drops. When it drops enough for the feedback rod to bump the valve, it raises back up. Repeat.

On the M7040, there are two single acting lift cylinders both external to the transmission for the 3 pt. A leak in either of the cylinders would be noticeable.

A leak in the internal control valve is possible but unlikely.

With draft control and position control, there are lots of adjustment rods to be out of calibration.

Dave M7040

 

[Tx Jim]

Dave
Thanks for correcting my mistake about possible RS piston leakage. After reading your reply it dawned on me M7040 doesn't have RS piston seals. I knew they didn't because I own a M7040 & have studied their hyd system. Dang ""oldtimers"" flared up again..
Thanks,Jim