Brakes: hillholder rebuild

[55 56 PREZ 4D]

I bought a seal kit from S.I. The copper washer for the end cap does not fit into the recess at the end of the body.
I called S. I. and was told there are different units, that they buy the kits made up, and to try finding a copper washer at a local brake shop. No luck finding one so far. There was a rubber o-ring or flat washer in the hill holder upon taking it apart,[no copper washer] is this a correct piece ?
I was told I needed natural rubber not Buna-n for a brake system. Where can I get natural rubber o-rings ?

[Cultural_infidel]

Buna-N will fall apart. Natural Rubber orings are somewhat hard to come by. For brake fluid, you would want EPR/EPDM. I work for an oring/hydraulic shop and we get people trying to put Buna orings in brake systems all the time... including 18-wheelers. What is the size of the oring? Maybe I can send a "sample" to you.

[Welcome]

I bought a seal kit from S.I. The copper washer for the end cap does not fit into the recess at the end of the body.
I called S. I. and was told there are different units, that they buy the kits made up, and to try finding a copper washer at a local brake shop. No luck finding one so far. There was a rubber o-ring or flat washer in the hill holder upon taking it apart,[no copper washer] is this a correct piece ?
I was told I needed natural rubber not Buna-n for a brake system. Where can I get natural rubber o-rings ?

Been there done that!!!

Ended up buying & tearing down a bunch of well used Hill Holder (NoRol) valves. All had the non-cooper type end cap gasket. Is your original gasket in good enough shape to try re-using it??

[55 56 PREZ 4D]

Welcome: Yes it does look like the existing gasket will be good enough to use again, That may be the way I will have to go.

Cultural Infidel: Thank You. The existing gasket is 1 1/8" I.D., 1 13/32" O.D., and where it's flattened, just under 1/16".
So it looks like a #-122 o-ring would fit.[1 1/8" I.D., 1 5/16" O.D., 3/32 C.S.]

Thanks for the information and the offer
Dan

[Welcome]

Welcome: Yes it does look like the existing gasket will be good enough to use again, That may be the way I will have to go. >>>Thanks for the information and the offer
Dan

If you decide to re-use, I'd suggest doing a pressure test of the HillHolder/NoRol valve assembly after rebuild but BEFORE reinstalling to the frame. I tested mine about 36 hours under constant pressure before I felt confident enough there would be no leaks/seeps/weeps.

PM if you want to know how I set that test up.

[Cultural_infidel]

Welcome: Yes it does look like the existing gasket will be good enough to use again, That may be the way I will have to go.

Cultural Infidel: Thank You. The existing gasket is 1 1/8" I.D., 1 13/32" O.D., and where it's flattened, just under 1/16".
So it looks like a #-122 o-ring would fit.[1 1/8" I.D., 1 5/16" O.D., 3/32 C.S.]

Thanks for the information and the offer
Dan

Happy to help!

I have plenty of -122 EPR o-rings on the shelf. PM me your address and I will shoot a "sample" or 2 your way!

Sean