MF40 Hydraulic control valve question

akwells

Member
Good morning. I've recently purchased an MF40 industrial tractor with loader and backhoe. The original Cessna loader control valve had been replaced by a Hydro-Pack 2P80 before I got this. If I'm understanding the specs and converting to US units correctly, that's a 21 gpm, with max presure of 4351 psi.

The loader lifts ok (haven't really worked it a lot yet), but it was leaking fluid badly at the control valve. I found that both spool end caps were bent and broken in pieces.

I'm trying to figure out what happened and why, how to repair it, and how to prevent it from happening again. I'm fairly new to hydraulics. I do want to do a pressure test on the pump, but I feel like I need to get this put back together first.

Is the spool supposed to be able to drop out the bottom of the block so far (it's at least 1/2" longer than the end cap will allow)? Are the washers supposed to be bent? And can I simply find new seals and caps and put it back together? Are they standard items?

I appreciate any help or tips you all have. Incredible site for knowledge here.
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Are you in a place with winter freezing? Maybe with the leaking some water pooled in there and froze in winter. Would
happen to ours when we got it. Stored inside with heat, but after working for about 20 minutes out in -15 weather would
start to stiffen up. Heat gun would restore movement. After removal and cleaning, problem was solved.
 
Thanks for the reply!

At first I wondered about freezing. But I've noticed that the bottom caps are actually bent downward, like they were pushed downward. The bend was probably 1/16" or more. There didn't appear to be any water in the cap, and we get some freezing spells but that would have been extreme.

It almost looks like the spool is too long for the block. I'm wondering if this thing was pieced together. Could the spool be for a float setup? I know those are longer. Could it be that the spool came down and pushed/cracked the bottom caps?

It's likely I'm just going to get a new control valve that has the float capability anyway. I don't know if I'd ever find the caps and seals for this one. I was just wondering what the experts thought.

Thanks.
 

I would expect finding parts would be a very long shot, so would agree with your thought of just getting a new loader valve with float position on the boom spool.
 
Yes, I've pretty much just decided to replace the whole valve assembly. I just need to find one closest to what I have. Thanks all.
 
That valve should be able to be replaced by a (Chief) Model 2P80 control valve.

Grainger shows to have that valve for $282.93 (cheapest I've found)
 
Thank you. I ended up getting this same valve and it is working good. It was easier than trying to find parts for the old valve. I still want to test the pressure of the system, but it will at least hold the loader bucket in the air now. Thanks again. Now, on to the next thing.
 

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