Hi there, Anyone up for a mechanical engineering detective story based on my 1965 MF135's hydraulic system.
Serial number of my tractor is 118536.
Symptoms:
Many operating hours, and about 10 years, ago the multipower engine braking in "hi" failed for reverse only.
Very recently the multipower no longer selects "hi" at all. The knob and linkage moves, but nothing happens.
At the same time the 3 point linkage no longer lifts, but in a very strange failure mode. At absolute dead idle, the 3PL will lift, including a reasonably heavy slasher. But at anything much higher than idle, including all the way up to full revs, nothing moves. This really surprises me as I would have expected it to be the other way around if there was wear and leakby somewhere. Once the 3PL is raised, very slowly, and then the engine shut down, the 3PL still takes ages to slowly drift back down. No change to how it's been for years - perhaps takes 20-30 minutes to go from fully up to down.
I have checked the oil level with the dipstick on the response speed quadrant. Seems ok.
So the detective story begins - please help me write it by challenging my assumptions and adding anything from your knowledge.
Because the 3PL takes ages to drift back down, I'm assuming that the actual lift cylinder and control valves for it are OK.
Does the "operate slowly at low speed, but not at high help anyone???
What do you think please?
DougMF135
Serial number of my tractor is 118536.
Symptoms:
Many operating hours, and about 10 years, ago the multipower engine braking in "hi" failed for reverse only.
Very recently the multipower no longer selects "hi" at all. The knob and linkage moves, but nothing happens.
At the same time the 3 point linkage no longer lifts, but in a very strange failure mode. At absolute dead idle, the 3PL will lift, including a reasonably heavy slasher. But at anything much higher than idle, including all the way up to full revs, nothing moves. This really surprises me as I would have expected it to be the other way around if there was wear and leakby somewhere. Once the 3PL is raised, very slowly, and then the engine shut down, the 3PL still takes ages to slowly drift back down. No change to how it's been for years - perhaps takes 20-30 minutes to go from fully up to down.
I have checked the oil level with the dipstick on the response speed quadrant. Seems ok.
So the detective story begins - please help me write it by challenging my assumptions and adding anything from your knowledge.
Because the 3PL takes ages to drift back down, I'm assuming that the actual lift cylinder and control valves for it are OK.
Does the "operate slowly at low speed, but not at high help anyone???
What do you think please?
DougMF135