MF 35

[Ron Kanouse]

What would cause the lift arms to drop on a MF 35 as soon as it is shut off or as soon as you push the clutch all the way down?
 

[Inno]

Put simply, a leak.

There are numerous little O rings throughout the lift system, pump, standpipe and where the hyd. cylinder mates with the lift cover. It's possible that you need to replace all the O rings and while you're in there it might be a good time to consider rebuilding the hydraulic pump.
You might also get away easy if it's one of the O rings on the stand pipe between the pump and the lift cover. It's very simple to remove, just two bolts and maybe a tap with a plastic mallet and you should be able to remove it. There is an O ring on the end of the pipe which mates with the pump and one on the under side of the plate where it mates with the top cover of the lift. If you are lucky that might be all it is.

It could also be a stuck control valve which would involve removing the top cover and the pump. Could be worn out rings on the lift cylinder. Now keep in mind that under normal operation it will leak down after maybe 10-20 minutes with an implement on, the heavier the item, the faster it will leak down but if it's as soon as you push the clutch all the way down it's a definite leak somewhere.
 

[Michael Manning]

Must be a common ailment, my TO-35 does exzactly the same thing!
 

[Ron Kanouse]

How hard is it to replace the rings on the ram? Do I have to spilt the tractor?
Thanks for the help.
 

[Inno]

No, you don't have to split the tractor but you do have to remove the lift cover, the plate the seat is bolted to. It is quite heavy to lift so a chain block or another person would be helpful.
Remove the stand pipe first, remove all the attaching bolts and lift it off being careful as the controls which engage with the pump are hanging from/bolted to the bottom of it.
Once you have it apart and all the O rings replaced you will have to readjust the controls so they work properly.
John (UK) has a great set of instructions on doing this. It's not something you can do by trial and error, you must follow the directions or you risk damage to the lift system or it simply may not function correctly.
 

[miner09]

You can order a DVD on hydraulic repair from this web site. It show how to remove and repair. Good information.( but it needs more close up pictures)
 

[miner09]

Cost $24.00
 

[Bob Mc]

Before you take it apart you can do some troubleshooting. Remove the right side inspection cover, you may have to drain some oil out down to the lower bolt hole on the cover. With engine running, operate the hydraulics and look inside for leaks, keep your hands out of the inside while it is running. Using an inspection mirror you can look up at the lift cylinder and where the hydraulic pipe goes into the lift cover for leaks. If it is dropping that fast it could be the lift cylinder. You can also look at the oil to see if there is a lot of turbulence coming from the pump. Then when you shut it off you can look to see where it is leaking down.

Bob Mc
 

[Ron Kanouse]

Thanks I will try all this and see what I can find out.
 

[John(UK)]

It is not uncommon on this hydraulic system, it can be the valves and the Pistons in the Pump that are worn and sticking, the Lift Cylinder scored and the rings maybe broken or just worn. It could be also be a blown "O" ring
If you want some written info about troubleshooting this hydraulic system, email me and I will send it..John(UK)...fergusontractors@hotmail.com
 

[John(UK)]

The problem you have is called wear and tear, they didn't do it when they were new. Being as the tractors are all around 50 years old, I think that leaking down can be expected, but it is repairable..John(UK)...fergusontractors@hotmail.com