# Installing rockshaft piston seal on Case 430 tractor



## oldrndirt (Aug 5, 2014)

Anyone know the secret to installing a 3.250" I.D. plastic sealing ring on a 3.75" O.D. piston? The sealing ring looks to be made of stiff neoprene and resists all efforts to stretch it over the piston. I soaked it in boiling water and had no better luck. Do I have to make some sort of lathe-turned wooden forcing cone to do the job? Do I have the wrong seal? Both old and new are dimensionally identical with the old one being translucent brown as opposed to the new black one. Both feel to have the same durometer.

Baffled in Barberville


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## oldrndirt (Aug 5, 2014)

*Rockshaft seal installation*

Eureka! I found an easy easy to do it! Let me know if you're interested.


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## bablsk (Dec 30, 2014)

oldrndirt said:


> Eureka! I found an easy easy to do it! Let me know if you're interested.


would like any info on how to do this


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## oldrndirt (Aug 5, 2014)

1. Adjust the faces of a wood vise so that the piston (crown-to-skirt) is a sliding fit.
2. Hook the seal over the crown of the piston and slide it between the wood faces of the vise.
3. Spray the piston and seal with WD40 or silicone lubricant.
4. Using a wood or rubber mallet, start tapping on the exposed side of the piston so that it is forced lower into the sides of the vise. Take care that the seal rides over the edge of the crown as the piston goes further into the vise.
5. Continue tapping until the skirt of the piston is flush with the top of the vise and the seal is completely on the piston.
6. Remove the piston from the vise and by hand, slide the seal down the piston skirt until it snaps into the seal grove.
7. You're done.


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