Minneapolis Moline 445 hydraulic help!!

Mm45

New User
Ok so I have a 1956 Minneapolis Moline 445 universal. I recently rebuild the hydraulic pump being extremely careful not to damage the plates or internal components. The IT manual claims that the "early" style pump, which I have, isn't serviceable. I put it back on the tractor and when I cycle the 3 pt hitch fluid starts to spew from the top 3 bolts and between the outer and center plates. Has anyone had experience with this pump? I would like to see an exploded view of the pump because my manuals don't provide one, torque specs of the pump bolts and if there is supposed to be some type of gasket in the machined "groove" between the outer and center plate. Thank you.
 
If I remember correctly, I think I read somewhere that the early pumps with the brass wear plates were to be coated with a thin layer of shellac for sealer as there were no gaskets in them. I will take a look in the parts book to see if they have a break down of the pump.
 
Thank you. There is actually no brass ware plates inside the pump. Just the 3 cast plates that make up the pump
 
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I went and looked at the 445 pumps I have here and the early M5 one. There were 3 different configurations of that style pump. The early 445 has the pump with no wear plates, as you already know, they have one on the 5 Stars with the brass wear plates with no gaskets, IT manual mentioned using a small amount of shellac for sealer. Not sure if they used that style on the 445s, wouldn't doubt it though. The later 445 I have, has one like my early M5 which if it is like the replacement one I got for my 5 Star has an "E" style rubber gasket and metal back-up retainer. When I got seals for that one time they gave me a blue nylon type gasket that didn't work. I happen to find the rubber ones with the metal retainer as I mentioned, which did work. You might be farther ahead to look for a different pump. A 445, 4 Star possibly Jet Star should fit it. The brazing on the one side might have warped the outer plate some and when you re-install it, it cant hold the pressure. The parts books don't give a breakdown of the early pumps, just the later styles.
 
(quoted from post at 20:44:06 11/09/15) I went and looked at the 445 pumps I have here and the early M5 one. There were 3 different configurations of that style pump. The early 445 has the pump with no wear plates, as you already know, they have one on the 5 Stars with the brass wear plates with no gaskets, IT manual mentioned using a small amount of shellac for sealer. Not sure if they used that style on the 445s, wouldn't doubt it though. The later 445 I have, has one like my early M5 which if it is like the replacement one I got for my 5 Star has an "E" style rubber gasket and metal back-up retainer. When I got seals for that one time they gave me a blue nylon type gasket that didn't work. I happen to find the rubber ones with the metal retainer as I mentioned, which did work. You might be farther ahead to look for a different pump. A 445, 4 Star possibly Jet Star should fit it. The brazing on the one side might have warped the outer plate some and when you re-install it, it cant hold the pressure. The parts books don't give a breakdown of the early pumps, just the later styles.

Do you know if there is some type of seal that goes into the groove of the one plate?
 
I will take another look in the parts books but I don't believe there is. My guess the grove is to take out any oil that leaks by the gears between them and the out side of the pump. Only thing is if the plates of the pump are wore it just creates more of a leak.
 
(quoted from post at 18:58:47 11/10/15) I will take another look in the parts books but I don't believe there is. My guess the grove is to take out any oil that leaks by the gears between them and the out side of the pump. Only thing is if the plates of the pump are wore it just creates more of a leak.

Great. Thank you. Nice to find someone knowledgeable. I need torque specs for the bolts as well. My manual says the 6 larger bolts are 11 inch pounds and the smaller 2 are 7 inch pounds. Doesn't seem like enough to me but maybe it is.
 
Thank you for the compliment but there are a lot of guys on here that know more than I do. An older gentleman told me once... "Experience is better than knowledge" I think that is a very true statement. I will take a look and see what I can find out for you. I do know enough to be dangerous though lol...
 
Early 445 pump had no gaskets. They were just metal on metal. Check for debris,nicks or warpage. Did the pump leak before rebuild?
 
(quoted from post at 07:10:37 11/15/15) Early 445 pump had no gaskets. They were just metal on metal. Check for debris,nicks or warpage. Did the pump leak before rebuild?

Not externally like it is now. The main seal was bad so it was leaking fluid into the case so while I had it apart I put new bearings in it. It's perfectly flat. I removed it from the tractor yesterday to check. I also torqued the bolts to 125 inch pounds and spun the pump by hand. I didnt feel the 11 inch pounds the IT manual says was enough. T
 

Hi... where did you get those adjusters on each side for the 3 point hitch?

Mine are solid homemade with no adjustment metal pieces welded together. Thank you
 
Alan; A pump from a late 4 Star or Jet won't work because they are external pluming. He needs one off a tractor with internal pluming.
MMDEL
 

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