MF40 Hydraulic Issues

[KevinJay]

I have searched the internet and through the threads but have been unable to locate some information. I am trying to help my neighbor, a disabled military vet, get his machine working properly again. I am mechanically inclined and know how to wrench, but i haven't really messed with tractors or hydraulics much. This has definitely been a learning process. He states that the hydraulics were working fine when he parked it. Now the backhoe hydraulics aren't working, it just whines went the lever(s) is moved. The loader hydraulics still work. What I've gathered is that it has a separate front mounted pump that runs the loader and backhoe with an external in-line filter. I have located what i would consider the location to add hydraulic fluid on top of the right arm of the loader (see attached pic). However, I can't determine how to assess the level of the hydraulic fluid. I did find a hydraulic hose that looks to be supplying the backhoe that has lost the protective rubber (outer sheathing). It is missing where the hose bends and appears to possibly be restricting flow. I thought to: check fluid level, change filter, and replace that hose. Does anyone have any thoughts or able to answer the questions? Thanks

1. Is the place (cap) on the right arm of the loader the place to add hydraulic fluid?

2. Where/how do I check the hydraulic fluid (I know where to check the transmission/hydraulic fluid on the right side of the case inside the cab, but the backhoe/loader hydraulics seem to be a separate system)? Do I remove the silver piece under the cap? Will it matter if I "over" fill it?

3. To remove the external in-line filter, do the hydraulic arms need to be retracted? At this point, the backhoe arms are extended and not working.

4. What is the lever to the right of the seat for? It seems to be immovable.

5. The transmission fluid level is displaying above "full" (the dipstick on the right of the case under the seat). Does this matter or should I drain some out?

Specs:
1975 MF40
SN: 9A 214071
Loader: MF32
Backhoe
3 cyl diesel

 

[ET]

There is probably a oil level plug in the loader frame somewhere. Fill it till oil runs out the hole. Unscrew the whole breather to add oil.

 

[Harry in Ky]

Actually, the breather cap/fitting once removed may reveal a dipstick. That was common on many industrial loaders.

 

[Jim.ME]

You took the breather cap off now you need to unscrew the breather base and see if there is a dipstick hanging from it. That is what some had. If not you can use a stiff wire and figure you need oil about 1/2 to 2/3 the way up that mast. That is where hydraulic oil would be added.

That could be set up with power beyond which would allow either the hoe or loader to be used just by using the loader or hoe controls. Or it could have a diverter valve that has to be shifted one way or the other to supply either the loader or the hoe. You saying the loader works and it just whines when the backhoe lever is moved sounds like a blockage in the return side. Do any lines have quick couplers? If so, make sure they are fully connected together.

As far as what that handle does, without seeing the lower part of it and what it hooks to it is hard to say.

The transmission (internal hydraulics is separate from the loader and hoe hydraulics.

The external filter can be changed as long as the engine is not running, and you do not move control valves while it is off.

 

[m16ty]

I’ve got a MF40, but my loader is a little different. Mine has a filter mounted on the loader upright where this one has 2 hoses coming off of it, that appears to be going to the backhoe. My hydraulic filler is in the same place as yours, there is a dipstick on mine attached to the breather cap.

The lever beside the seat is the differential lock.

Mine has the front pump, fluid from the pump goes to the loader valve mounted on the upright. The loader valve has a “power beyond” port that feeds the hoe, then fluid goes from the hoe, through the oil cooler, and then back to the pump. I removed the hoe from my tractor and now have the power beyond circuit feeding a set of auxiliary valves.