Farmall Super A hydraulic block safety valve stuck

Scott A Johnson · Mar 25, 2013

Hi, I need some help with the safety valve that is in the hydraulic block assembly. How do you remove the safety valve piston? I have been able to remove all other pieces from the block, but the safety valve is in the "open" position in its bore. The spring and the safety valve sleeve come out, but then there is a very small opening and the piston sits behind it in a smaller size bore. I don"t see an o ring in the diagram that would prevent the piston from freely sliding back and forth, but it wont. Does that wall with the small opening come out? Is it a plug that once it is removed then you can pull that piston out? I am stumped. Any help would be greatly appreciated.

WellWorn · Mar 25, 2013

Hi Scott.
I don't have access to my parts book (visiting 'downtown' for some high speed internet, vs the snail dialup out at the farm), but at one time I found a touch control service manual reproduction posted on the web, possibly from a link on YT - though I can't seem to locate it at present.

The TC-39 parts book has a pretty good parts breakdown diagram, which if you are doing much if any work on your SA, would be well worth the investment.

I did rebuild the touch control block on my SA, but I don't recall not being able to access the relief valve parts. If I recall it correctly (and I admit I could be wrong), the ball and spring install from the head side, with pump pressure internally ported to the ball side of the assembly. All you should have to do is make sure the port is not obstructed (blow it out with air), the valve (ball) seat is clean and shiny, and the ball has no pits. If in doubt of the spring's condition, replace it.

Hope this is of some help.

Well Worn

Scott A Johnson · Mar 27, 2013

Hi Well Worn, thank you for your reply. I think what you are referring to with the spring and ball is the pressure regulator valve. I am having trouble with the safety valve which is directly above the pressure regulator valve. The safety valve has a spring that is 1&15/16" long that sits in a cup (safety valve sleeve) and then behind that is the safety valve piston. That safety valve piston won't slide out of it's bore which is a much smaller diam. bore than the sleeve sits in. That sleeve backs up against a plug with about 1/8" diam. hole in the middle that I can look thru and see the piston, but the hole isn't large enough to get the piston through. My thought is that plug must come out somehow, but how? Case sells the piston so I know it must come out. Any continued help from you or any readers would be appreciated!

Anonymous-0 · May 7, 2013

Not sure which version you have. Just went through my Super A with new seals and such and found that the safety valve was missing piston. Made one from 1/4 bolt and working ok. It sounds like you have spring, sleeve and piston. If so the sleeve with 1/8" hole needs to be removed. You will find large hole into block with a piston about 7/8" long. Try blowing out sleeve or with tool that spreads out against inside sleeve and twist. Sleeve binding is problem. Les

Farmall Super A hydraulic block safety valve stuck

Scott A Johnson

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WellWorn

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Scott A Johnson

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Anonymous-0

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