Soft Brake Pedal
Thread Starter
Instructor
Joined: Nov 2000
Posts: 179
Likes: 2
From: Detroit Area
Soft Brake Pedal
My 71 sat in the garage for 3 years due to a carburetion problem. When I parked it, the brakes worked fine. When the carb problem was fixed, I found that the brake pedal was soft. When I tried bleeding them, I got dirty fluid, so I decided to replace the calipers.
I blew out all of the old fluid with compressed air, and now I have with new SS calipers, hoses, a new master cylinder, and DOT 5 silicone fluid. I used a power bleeder, but I still have a soft pedal (goes all the way to the floor, but can be pumped up). Where could the air be hiding?
I blew out all of the old fluid with compressed air, and now I have with new SS calipers, hoses, a new master cylinder, and DOT 5 silicone fluid. I used a power bleeder, but I still have a soft pedal (goes all the way to the floor, but can be pumped up). Where could the air be hiding?
Burning Brakes
Joined: Nov 2005
Posts: 1,137
Likes: 51
From: Cartersville GA
Try this link. If it doesn't work, do a search on this (C3) forum for TOM454. He has a write up that is excellent...
http://forums.corvetteforum.com/show...r+bleed+brakes
http://forums.corvetteforum.com/show...r+bleed+brakes
Race Director
Joined: Feb 2005
Posts: 16,100
Likes: 17
Your master cylinder could be leaking internally.. get a new one..... (assuming your brake bleed was ok). I had same issue once...soft pedal..then they would pump up after power steering fluid got warmed up...
Melting Slicks
Joined: Mar 2007
Posts: 2,100
Likes: 12
From: Frederick Maryland
If your system is not 100% flushed of all previous brake fluid and 100% completely bled of air, DOT 5 fluid can give you a soft pedal. Microscopic air bubbles love to hide in DOT 5 systems creating problems. It's a wonderful product but it requires diligent procedures when converting to it.
Replacing the master cylinder is a good idea as already recommended.
Replacing the master cylinder is a good idea as already recommended.
Thread Starter
Instructor
Joined: Nov 2000
Posts: 179
Likes: 2
From: Detroit Area
Soft Brake Pedal
Thanks 69monzacpe for the link. I will try Tom454's process. I had installed a new Master Cylinder already, but will try Tom454's suggestion for checking for proper bleeding and seal assembly.
