Master cylinder upgrade?

Closed Thread Subscribe

Thread Tools

Search this Thread

Dec 13, 2014 | 09:37 PM

BlackC3vette

Thread Starter

Burning Brakes

Joined: Jan 2012

Posts: 943

Likes: 73

Master cylinder upgrade?

A little chilly today, but a nice day, I took the 80 for a ride. Returned to the garage and popped the hood to adjust the choke. I noticed the master was leaking some fluid from the rear of the cap. I took the cap off and cleaned up the gasket and the mating surfaces. The master is the original which has the normal dis-colorization from being the original master and I thought about replacing the cap with a chrome one, but then I would have a chrome cap on a crappy looking master. So what's the most popular upgrade? A new master and paint it before installing or buy a chrome unit?

Dec 13, 2014 | 09:47 PM

7T1vette

Team Owner

Joined: Jan 2006

Posts: 37,637

Likes: 3,116

From: Crossville TN

Your original master cylinder is a MUCH better piece of hardware than any aftermarket parts "knock-off". You can buy a rebuild kit for your M/C and it will be good-as-new. A good rebuild kit will cost about the same as a complete 'new' (

) M/C; but the end result will be much better if you just rebuild what you have. I would suggest getting the rebuild kit from a NAPA store.

P.S. The rebuild kit has a new set of valves, springs, and seals/gaskets in it. As long as you don't find any significant pitting in the valve bores, it should be fine. You may find some minor rusting/light-pitting, but using some crocus cloth to clean that up should do the job.

Last edited by 7T1vette; Dec 13, 2014 at 09:50 PM.

Dec 15, 2014 | 12:55 PM

Roozstr

Instructor

Joined: Jun 2014

Posts: 119

Likes: 3

From: Boise ID

A brake cylinder hone works great for cleaning that bore up. Got one in my tool box.

Last edited by Roozstr; Dec 15, 2014 at 12:58 PM.

Dec 15, 2014 | 01:47 PM

MelWff

Race Director

Joined: May 2006

Posts: 18,710

Likes: 2,574

if it is only leaking from the cap, replace the cap gasket. With careful masking you can paint the master in place to make it look new again.

Dec 15, 2014 | 02:54 PM

Easy Mike

Team Owner

Joined: Jun 2000

Posts: 38,923

Likes: 1,481

From: Southbound

Cruise-In II Veteran

Quote:

Originally Posted by MelWff

...if it is only leaking from the cap, replace the cap gasket...

That's what I'd do.

Mar 12, 2021 | 09:55 AM

NRAROX

Instructor

Joined: Nov 2015

Posts: 246

Likes: 20

From: St. Louis (more or less) Missouri

How do you 'apply' crocus cloth to such a small space? Wrap it around a dowel or some other cylindrical object? My cylinder has some surface discoloration and some very, very small pits. I'm hoping to clean it up.

Thanks for your help.

Mar 12, 2021 | 03:47 PM

Cmurray79

Racer

Joined: Jan 2020

Posts: 388

Likes: 117

From: Tacoma, Wa

I agree, get the ac delco master cylinder for reliability. But for looks and a little bit of weight savings, there is this one...

https://www.jegs.com/i/JEGS/555/631000/10002/-1

I intsalled it not too long ago, no leaks and it fits well.