Diagnosing Brake System
Thread Starter
Melting Slicks
Joined: Dec 2015
Posts: 3,181
Likes: 732
From: Texas City, TX Texas
Diagnosing Brake System
I'm sure this has been covered a million times, but not sure how to search. When I first got my '74, the brakes were pretty bad. I only drove it a couple hundred miles before we pulled the engine for a rebuild. I'm sure they have only got worse, and I'm afraid to even test drive it. Do I need to take all the calipers apart to see which is leaking? I don't know if they are original(very doubtfull), ss sleeved o ring(hope so), or what. If someone could post a link to testing the brake system without driving the car I'd be most appreciative. I can't afford to just replace everything if not necessary.
Le Mans Master
Joined: Sep 2002
Posts: 5,236
Likes: 898
From: Myrtle Beach SC
When did you "first get my 74" in 1974 or more recently. If the brakes were bad before you built the engine, then in all likelihood, they remain bad. Rather than dither around with testing, and because its a critical safety issue, approach it by recognizing you have got to rebuild the brake system so YOU KNOW they work correctly! Lots of posts here what to look for but look at one caliper and it will tell the story of probably all four. If the fluid is mucky, rusty looking, then you know all four will require attention. And if the fluid looks like that described, the entire system is contaminated, including the Master Cylinder. At that time you can inspect and determine lip seal vs. O-ring and whether they are stainless steel inserts or the original steel that contributes to mucky, rusty fluid. Its this sort of contamination that will lead to leaky calipers and your foot going to the floor when depressing the brake pedal...THAT'S THE TEST!.
Hope this helps!
Hope this helps!
Thread Starter
Melting Slicks
Joined: Dec 2015
Posts: 3,181
Likes: 732
From: Texas City, TX Texas
We are towing the car home tonight, first thing I will do is look in the master at the fluid. I have pretty much resigned myself that I will need to at least rebuild the calipers, and probably replace the master.
1967 Pedal Car Champion
Joined: Mar 2020
Posts: 9,137
Likes: 4,248
From: US-PNW
The first thing to look for in either the calipers or master is pitting in the piston bore(s). Any pitting means machining and probably sleeving; in lieu of that, replacements are the most economical way to approach it. Your old items can be returned to the seller as cores.
Drifting
Joined: Aug 2019
Posts: 1,339
Likes: 225
When you say "bad" what do you mean? If the calipers are leaking, you'll see a line of brake fluid across the bottom of the tire. If you are really concerned, you could rebuild the calipers and master yourself, and save some $$$. The kits for the whole thing should be under $100. Light surface rust can be cleaned up with a scotch pad. Just clean everything up with brake cleaner.
Is my vette stock?? HAHA
Joined: Oct 2015
Posts: 20,216
Likes: 9,354
From: Im not allowed to tell you
2020 C3 of the Year Finalist - Modified
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
If you go the caliper rebuild route, look at CSSBinc for rebuild conversion kits, you can make them o rings yourself. And look at their o ring calipers
