Devin Yarbrough

When I got my 76 vett the brakes went almost to the floor before they would engage but they still worked, now when you start it up you still have the soft pedal but it works until you drive it for about 2 miles then they completely go out, Avon opening the hood I discovered that my master cylinder was way to hot to even attempt to touch so I replaced the master cylinder checked all the brakes and nothing appears to be rubbing (that I could see) I've flushed and bled the system over and over. No lines are resting on anything that will get it too hot. I just don't understand what's going on here so if anyone has experience with this kind of problem please help.... oh and if I leave it in park with the engine on it doesn't heat up the brake fluid or master at all, only when it's in drive and once the brakes go out you can faintly here a scrape from one of the passenger side wheels but I couldn't find any scraping.

Tampa Jerry

I will take a stab at your problem. Either something is sticking or is not adjusted correctly. When this happens can you feel each caliper to see if they are all hot. Could be a clogged rubber line or lines at each wheel or your calipers may need rebuilding. The rubber lines may look OK from the outside but could be clogged on the inside. Fluid can enter the caliper and not get out. Also a few pistons may be sticking in the bore in each caliper. Lastly, the slight drag you are feeling may be a M/C rod set incorrectly. As you drive, things heat up and expand and create drag. Lastly, if you are loosing your pedal, consider measuring the run out on each rotor. If it is over .005, you are pumping air into the system. Good luck. Jerry

7T1vette

Have you replaced the [rubber] flex lines that connect the calipers to the brake lines? If not, they are probably 'toast' [internally] and are blocking brake fluid flow to the calipers. That is potentially a dangerous situation, as the calipers can become partially applied while driving. They can severely overheat (sounds like your problem) and eventually catch a tire on fire!!

If you haven't replaced them all, please do!!

gkull

We do Vette repair as a side business. People neglect ever changing the brake fluid. In the past year I have had to replace all the hard lines on two vettes because they were rusted clogged from the inside. Holding one or more calipers clamped down on the rotor

If the vette is from a wet climate it is a common problem.

crisko

Just had this problem after installing a new master cyl. Had to adjust power booster rod.

Devin Yarbrough

Thanks yall I'll try everything this week and post results

doorgunner

Like the members said: The fastest repair would be to shorten the rod between the master cylinder and the power brake booster by one or two turns....then drive around in an empty parking lot to see if the problem is solved.

Then check to see if one caliper is much hotter than the others.

Next would be to replace the rubber brake lines at each caliper and bleed all the overheated fluid out of the brake lines