Hairy Olds

Ok so my master cyl leaks a bit from the piston opening. Tore it apart and the bore is pretty good except for the last sealing surface has a little corrosion and the seal has a small amount of rust embedded on it.
What I need is a good replacement rebuild kit for a 1" bore. I would like fresh seals not a 50 year old kit.
Any good suggestions and manufacture name and part #s. This is for a 67 442
Inline is not a choice!

Schurkey

I'd start with the local NAPA or O'Reillys or Advance.

A rebuild kit typically costs about the same as a complete rebuilt master cylinder, but doesn't have a usable warranty. I'd be examining the rebuilt cylinder.

oddball

Rockauto doesn't list any, which is a bad sign, and they only show masters for drum cars.

Might have to get a reman unit. Just make sure to take it apart and inspect it. I've gotten ""new"" master cylinders with deep scratches in the bore.

Hairy Olds

I looked at rock and was not impressed with what they have. The bore in what I have is really good. It just leaks from the last seal which I believe is over 10 years old.

Schurkey

The only functional difference between a "front disc" and "4-wheel drum" master cylinder for that year is the residual check valve. GM quit installing residual check valves in drum master cylinders back in '71 or so. I bet the aftermarket quit installing them, too.

In other words...I bet that "drum" master cylinder is exactly what you need. If not...remove the residual check valve from the outlet that supplies the front brakes.

"I" would be concerned about that "corrosion" in the bore of the one you have.

You sure you need a 1" bore? I'd have expected 1 1/8" with front discs--and that's available. Do you NOT have a power booster?

Hairy Olds

I have 4 wheel drums, not real impressed with them but it is been this way since born.
The bore is clean and I used a scuff pad to get rid of the rust at the opening of the bore.
I'll go looing at some of the parts stores on Tuesday for a service kit for the master.
I may be forced to put my service replacement CT master on.

mrolds69

I understand you want to rebuild it yourself. White Post Restorations can re-sleeve it in stainless and you would be done forever with it...maybe. I've never had anything done there, but they had a good rep in the past.

Schurkey

Ooops. Somehow I imagined you said you had front discs. Mia Culpa.

scrappie

Karps power brake in CA sleeved my MC with brass. Wasn't in a hurry but turn around was pretty quick. Thats if your looking to sleeve?

67 D88Custom

Hairy,

Found the attached 2013 C.O. thread on the same issue. Hope it helps.

https://classicoldsmobile.com/forums...ch-bore-72085/

Also, my Chevy friends claim that a number of their cars have/had 1 inch bore m/c. Late 60' Camaro is one mentioned and some late'60 and early '70 Corvettes. May be able to find a kit at a local auto parts store and compare with your parts.


Dave

Hairy Olds

Thanks Dave