Bassman76

I had the Master Cylinder in the 85 replaced by my local Mechanic. I did this because the brakes went to the floor and when I opened up the Master Cylinder the rear reservoir was brown and muddy looking the front was fine. Figured this should be the first step.
Picked up the Vette and all seems fine but within 10 miles the brake light went on and the brakes were still holding well but now what I expected..They closed so I could not bring it back right away. Checked the new Master and the front reservoir was only half full..I topped it off and pumped the brakes then took it for a ride and no change. Looked under the car and around the new master and did not see any leaks....The fluid has not gone down at all..It has been 2 days and have driven the Vette about 30 miles just checking if ant further changes in the Brakes
Not sure what could be the issue ?Maybe air in the lines....I plan on bringing it back but want to get some feedback from the group here first.
Any Thoughts? My Mechanic is not a Vette mechanic but brakes are brakes...It wen thru inspection here in PA with no issues...
Thanks, Mike

J W Drew

Hey Mike.
Go out and insure your parking brake handle is all the way down. Bet you will be surprised. Let me know.
JW

AirForceOne!

This part was the issue on my 90, not sure if your 85 has this part?

https://corvetteparts.com/item/brake...0-1994#details

playsdixie

on my 85, it fades in and out depending on how I hold my left leg against it.....just can't get it quite off.....

gerardvg

Hi Check the brake warning switch on side of the master cylinder, there is a brake bias spring that moves a piston if there is an imbalance.
I usually bleed the brakes with the switch removed, then refit the warning switch afterwards.
I think the spring loaded warning switch can jam the bias piston from returning to normal, unscrewing and refitting it should help. Check for any wet areas on the brake calipers or brake hoses.