1964 MF 165 Hydraulic pump help

[1msucub]

Before I get started, let me say a couple of things.... First, I absolutely love reading these forums. I believe some of the smartest, most adaptable individuals on earth are farmers. The amount of technical knowledge some of y'all have on here is amazing, so hats off to you. Secondly, I searched back years on this and other forums for the answer to my issue and struck out, so here I am. I am only posting this here and on the hydraulics forum. No other boards, unless someone here directs me otherwise.

I have a 1964 MF 165 that is/was equipped with Multipower. The lever is present, but the linkage is not hooked up. The electrical plug on top of the tranny housing that I read somewhere was also a part of it is present but the wires are cut. After pulling the top plate off, I found that the Multipower pump is also present but the top fitting where the line runs forward to the tranny is not connected (present but no line attached). The pump can be seen in the last two pictures I attached.

This is only relevant because my 3 pt lift is VERY weak, slow, and shaky (previous owner disclosed that when I bought it). I drained the fluid, which had minimal metal shavings, and flushed out the filter, which was in pretty good shape. You should be able to tell that the gears appear in excellent shape. New fluid and clean filter made zero difference in lifting ability. Therefore, I can't imagine it being anything other than the pump.

Everything I read said I'd need to split the tractor in order to remove the pump if the tractor was fitted with Multipower, but I'm just not setup to do that safely. Therefore, I tried it anyway. In order to even have a chance, I had to remove the small MP pump that sits to the front left of the housing, attached to the main hydraulic pump. Since it just pumped fluid up and right back out into the housing, I saw no harm. It got down to a couple of millimeters (not kidding) but I was able to wiggle it out. Made my day.

You should be able to tell in the pictures that the MP pump attaches to the main pump by bolting onto a heavy piece of angled iron that is bolted onto the main pump itself. There are NO line/fluid attachments between the two. The small pump has a gear in the back that is driven by the large gear in the back of the main pump. It is now rendered useless, and I don't intend on reattaching it. Here's the heart of my issue... This is the first time I've ever taken a tractor apart like this (thank goodness for the internet and the simplicity of old, reliable equipment) and I have no idea how to really assess what kind of shape the interior workings of this pump are in. The pump itself looks great (damage/wear-wise), but that, of course, doesn't determine functionality.

Ultimately, here are my questions:
1. Is there any reason why I couldn't leave the old MP pump off?

2. What am I looking for as far as signs of wear in my pump?

3. Where do I draw the line between rebuilding (kits seem to be $175-250) or replacing ($400-900) the pump?

4. How do I determine exactly what pump I'm dealing with (there are 2-3 out there that apparently are slightly different, but those differences seem important)?

5. Who do y'all trust for these type of parts? I've used Stevens in Louisiana, Yesterdays Tractor and a couple others and been pleased...

6. Is there anything more gratifying than doing something like this that you've never done before and impressing your two young sons?

Thanks so much in advance... Now to try to attach these pictures...

 

[Kenneth S]

1st. The electric plug on top of the transmission is the neutral safety switch.
2nd. The piston in the 3 point lift cylinder probably needs a new seal (when you shut the tractor off with the 3 point up, it will drop down on its own), you need to make sure the cylinder is not pitted, or scratched.
3rd. You have the old style Multi-Power pump that can be removed from the top, the newer ones can't.

 

[1msucub]

Kenneth...thanks for your time, friend. How much of a job am I looking at with that cylinder seal? It doesn't seem it would be THAT big of a task, but I'm an admitted novice. Anything I need to be especially careful about? Should I go ahead with the pump project if the cylinder seems fine (really don't want to fool with taking that lift cover off again)?

And thanks for the pictures...I figured there was a reason that I could get that pump out that wasn't my superior mechanical intellect.

 

[Kenneth S]

If you still have the top cover off change the seal in it now (its cheap, and easy to do) while you are doing the pump. You can hone the cylinder a little bit if need be, or replace it if its in bad shape (also look for any cracks on the cylinder, not common but possible). Its usually just a worn out seal on the piston, and make sure you measure the diameter of the piston because they had a couple of different sizes they used.

 

[1msucub]

I'll need to disassemble the lift cover in order to get the ram arm out of the way, correct? Will the piston then just pull out or is there a trick/special tool for it?

 

[1msucub]

Just to update, again for anyone out there along with Kenneth that has some expertise, the two plugs on the left side of the cam blocks are both missing their rings. The corresponding cylinders are scratched pretty heavily, as you can hopefully see in the pictures. It would seem to me that this would be enough to explain my problem, and that the easiest thing to do is a rebuild, as the architecture of the pump itself is in great shape. Kenneth, I also checked the inside of the lift cylinder, and it appears to be in pretty good shape. I can still replace the seal since I have the cover off, but still would like to know if I need to disassemble the workings of the lift cover in order to get the piston out. Thanks again.

 

[Kenneth S]

With the top cover off you can raise the lift arms, and remove the "dog bone" that goes from the lift arm shaft to the piston. You should be able to slide the lift piston out by hand, or use compressed air if needed (but be very careful if you use air). The piston in the lift cylinder will probably have 3 piston ring type seals similar to like you would see inside a engine.

That pump has seen a lot better days!

 

[1msucub]

Yes it has. Am I correct in assuming that missing rings would have a detrimental effect on the pump's ability to lift? If not, then I know less than I thought I did!

Getting the piston out sounds easy enough. Thanks, and I'll update as I progress. You have a favorite parts dealer by chance?

 

[Kenneth S]

You can remove the lift cylinder/piston assembly a little easier by removing the 4 nuts on the top side of the lift cover as indicated by the 4 red lines in the picture.

 

[1msucub]

Got the cylinder off (not easy.....the vertical lift assembly is bolted into the side of it. Yuck.) and this is what it looks like. The rings look decent but the seal doesn't even look like it is wider than the piston. Oil leaked from around the head as I tilted it to get the piston out, so if it leaks under NO pressure, I can't imagine what it's doing under HIGH pressure. The cylinder looks usable; I don't have the machinery to bore it down any, but I THINK replacing the seal (and maybe the entire piston? Thoughts?) will be adequate. Opinions?