MF 40B rear lift issues

AVRanch · Aug 2, 2016

I am new here and this is my first post

I just purchased a MF 40B and it is having problems with the rear lift. With the engine running and I operate the controls nothing happens. With the draft and position in the up position and start moving (forward/reverse pedals) the rear lift will go up. Nothing I do will allow it to drop again. I have to turn off the engine a wait a while for it to drop. I just got a copy of the service manual and it says nothing about this symptom and I am trying to figure out what could be causing it. Any help would be greatly appreciated.

Masseynut(Australia) · Aug 4, 2016

I gather your tractor has the instant reverse transmission fitted. With these transmissions, you don't have the luxury of live hydraulics or PTO drive.
Power to these functions only occurs when the drive pedal is depressed in either direction. You might like to place the travel gear sticks in neutral and depress the fwd/rev pedal. The hydraulics and PTO should be operational.
Now having this side of things sorted, you probably have a sticking hydraulic pump control valve. It's stuck in the raised position and that's why whenever the tractor is moved in either direction, the linkage raises to the top of it's travel with no control when working the levers.
The 40B was basically an industrial tractor primarily designed for using a front-end loader or backhoe, with less emphasis on 3 point linkage or PTO work.
Once the stuck valve problem is sorted, it won't be a "user friendly" tractor for that type of work, I can assure you. Having said that, they are of a heavier construction than the agricultural models in it's size.
hope this helps,
Evan.

AVRanch · Aug 4, 2016

Yes, it does have instant reverse. I didn't realize the pedals had to be depressed for the rear lift to work and the person I purchased it from didn't seem to know that either. I will try putting it in neutral and operating the pedals and try to get the lift functioning after work.

Yes, it's a big heavy tractor with a rear Gannon box which I will use to maintain the dirt road to my house (1/4 mile). It should work fine for that. The front loader is one of the major reasons I got it.

What is the correct procedure for fixing the control valve?
Can it be accessed from the side access covers or do I need to pull the top cover? If the side cover, which side? I may need to pull the top cover anyway because it's leaking oil and I want to get it sealed.
Any pointers on what I should do to fix the stuck control valve?
I know it's inside the case but don't know where it is or what it looks like. The service manual may help with that

Yes, I'm a newbie with tractors in general and I'm guessing this tractor will help get me over that.

AVRanch · Aug 12, 2016

I pulled the side cover off and saw the arm the operates the control valve and noticed it was missing the roller at the top of the arm.

I pull the top cover to see if I could find the missing parts.

I noticed some metal shavings. Most of them are copper and noticed the case has a chip missing.

Is it common to find the shavings like this?
Any idea what would cause the chip in the case?

Finished draining the oil and cleaned out the rest of the shavings in the bottom. Found the missing roller and down by the filter on the pump I found a large metal piece (not the chip from the case above). I can't figure out where it came from.

Any ideas where this came from?

After finding this and couldn't find the source I pulled the trans pan and everything looked good. No metal shavings or anything. I didn't pull the hydraulic pump to see if the metal piece was from it.

Found a new magnetic drain plug for the rear lift case and installed it.

I put it back together and added about 8 gallons of hydraulic fluid and everything is working fine now

Thank you for the help!

MF 40B rear lift issues

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