C1 Master Cylinder/Brakes

[Terry D.]

Who are the master cylinder/brake experts for 58-62 Corvette's?

[John F.]

Re: C1 Master Cylinder/Brakes

What do you need to know?

[Richard M.]

Re: C1 Master Cylinder/Brakes

Terry, what's up? Do you want info on who has the best MC's and parts, or are you having a bleeding issue or weird defect going on?

Rich

[Terry D.]

Re: C1 Master Cylinder/Brakes

Replaced the whole rear axle in my 62 and replaced the rear rubber brake line, bled the brakes twice with an automatic bleeder. Used almost a quart to make sure I had all the air out. Started at the right rear and worked to the left front as per instructions. I still have to pump the brakes to keep a good pedal. Can a master cylinder be bad and still not leak fluid anywhere? Had good bakes before I started this project. What am I missing here?

[Richard M.]

Re: C1 Master Cylinder/Brakes

Terry, You said, "Started at the right rear..." Typo? You meant left rear, correct? DOT 3 or DOT 5?

Either way, I've found the best method is a gravity bleed. After my Mityvac initial bleed(with teflon tape on the bleeder threads), then pedal bleed. Then finish with a gravity bleed. I always do this on any brake system(C1 or C2 or C3) when I use DOT 5 Silicone fluid.

It's possible you exercised the MC piston into a dirty spot in it's bore during a pedal bleed if you did that. This happened to me recently on a C3 "pedal" brake bleed. Had to replace the MC. Not saying this is definitely your problem but it could be.

Maybe try a gravity bleed for a hour or so. Do it at the left rear initially, then work your way CCW to the left front.

Rich

[Terry D.]

Re: C1 Master Cylinder/Brakes

yes meant left rear. how did you exercise the MC into a dirty spot?? Used Dot 3 fluid

[Richard M.]

Re: C1 Master Cylinder/Brakes

When the pedal goes to the floor during a pedal bleed, the piston goes into a bore area it hasn't seen since new.

[Domenic T.]

Re: C1 Master Cylinder/Brakes

Terry,
Usually when you have to pump brakes with proper bleeding it indicates that you need to adjust the brakes. The pumping puts a second burst of fluid in before the first go's back to the MC.
This was common after a brake job back then and even happens with the self adjust brakes until they adjust. That is one thing to think about. As it used to say in the manual adjust till you feel resistance then back off till you hear a slight rub.

DOM