51 M Farmall hydraulic leak

Hello, brand new to the forum here. Skip the first paragraph if you dont want my boring backstory.

I grew up in a farming family that moved over to construction and rental property when I was pretty young. But we kept our hands in it a little here and there. I have always loved classic equipment, but then the teenage years happened and I got away from it in favor of cars, girls, and starting a career. But now that I am married and in a comfortable career my interest has rekindled, and unfortunately I now have the means to feed it! My wife and I bought a small hobby farm and a neighbor that loves old iron just as much which bring me to the M.

My dad and I bought a 51 Farmall M about 12 years ago. It had been sitting in a barn for several years. A gallon of fresh gas and a set of jumper cables and it fired right up. I made a lot of money in high school bush hogging and disking gardens with that thing, it sat while I was in college, then when we moved to Central OK I went and fetched it from my parents, brought it home, and use it almost daily.

Its had a small hydraulic leak for years. Now it has become a big leak. It seems to be coming from the rear of the old belly pump. This tractor has a M and W live hydraulic system powering a 2 point fast hitch and a Char Lyn power steering system, along with a Norden wide front end. The belly pump is just being used as a reservoir. Ive been researching how to remove the pump and Ive got some questions.

The elbows coming out of the side of the pump need to be removed apparently, will those just screw out?

Also, if the belly pump was disabled will there still be an input shaft that needs to be removed and a seal that could be leaking?

Last question, it appears on the exploded view that theres
another gasket in there. So a seal around the shaft, and this other gasket, is there any other seal or gasket in there that I should replace while Im in there? My job takes me away for several days at a time so I wanna have everything to for sure fix it and get it done in one shot

Thanks in advance, I know just enough about turning a wrench to be dangerous

The elbows do turn out to remove. Plugging the holes with pipe plug is good. The pump can be taken out and a seal put in its entry hole. A plate can
be made to cover the opening. Jim

Hey Jim, thanks for the reply.

I think you misunderstood a little. Im only removing the belly pump to fix the leak, not removing it entirely.

Also keep in mind that the pump is heavy, probably 60 to 70 lbs. Have someone to help you if possible. If you put it back in use a ready sleeve for the seal
if necessary. It isn't a really complicated job. Ellis

If you remove the pump from the reservoir, it increases the volume, and can no longer leak at the shaft seal. Jim

Good to know, Ill see if its still there or not.

Also, Ive got a large floor jack and a good neighbor to remove it, I saw people say its nearing 100lbs

I need to do the same thing on my M. I'm thinking of putting threaded rod in a couple of the mounting bolt holes to guide it, and then lowering it with a floor jack just enough to replace the seal.

Ive seen that method, but Im lucky enough to have an extra set of hands to help me out

But Freightdog don't think of useing the side ports for oil return ports,if you do remove the original belly pump to get a extra 2 quart reservoir, they dead end,I agree there, in a slick position to be used for that,but u have to dril a hole in the casting to be used for that, and a drill bit will walk,so i took mine to a machine shop and he used a end mill to drill it. Hope this makes sense to you !!!!

Unit can leak at threads in side and fill ports, operating shaft, pump drive shaft, rear cover and pump mounting plate gasket and sometimes housings crack on a original system. Don't know how the M&W was done on your tractor. One way was to remove pump from housing and reinstall rear cover with a expansion plug in pump drive shaft opening. Housing operating lever shaft hole threaded for 3/4 pipe threads and used as a return port with aftermarket double acting valve. Also sometimes used for a fill opening with original IH double acting valve. Lower front of liftall housing was drilled and threaded for a 3/4 inch suction line to pump. But also one system used the original liftall valve parts with pressure line from pump supplying pressure with a special piece that installed in the original pump drive shaft hole after pump gears were removed and pump suction hole plugged. Lots of variations can be found depending on installer or parts used. With engine driven pump and a double acting valve with pressure relief I remove the pump housing and gears then make a flat plate to go on liftall housing. If using the original cover a expansion plug in the pump drive shaft hole and one at the original seal location makes double sure not to leak there. Do also need to plug the small oil hole that lubed the pump drive shaft when also using plug in shaft hole. Remove operating lever and shaft and plug the hole or thread and plug or use, after that the only place to leak is at the threads or gasket unless a cracked housing.