Locked Front Brakes
Thread Starter
Instructor
Joined: Aug 2002
Posts: 198
Likes: 0
From: Yucaipa CA
Locked Front Brakes
My front brakes recently locked up, accompanied by a hard brake pedal, and stayed locked through cycling my ignition on and of and on. I completely disassembled the brake systems down to removing the calipers and hoses. The only potential cause I could find was the vacuum booster check valve popped when I blew pressurized air thru it. Could it have stuck and maintained a vacuum when i released the brakes? I went ahead and replaced all of the brake components including the discs (they measured too thin to resurface) and the check valve. I also replaced all of the fluid for both front and rear brakes. The brakes work well now
Safety Car
Joined: May 2001
Posts: 4,740
Likes: 1,638
From: Fairfax Virginia
It is possible that the rubber hoses are causing it but not on BOTH wheels at the same time.
That sounds more like a master cylinder as I had a master cylinder that was really sensitive and then one day it just "locked up" (like there was a brick under the brake pedal) while I was at 70 mph in my BB C3. Fortunately I have a four speed and was able to slow the car down with that. I do believe a few hairs on my head turned grey after that experience, it was terrifying to be entering a Clover leaf at 70 mph when the posted speed was 20 mph.
The master cylinder was locked up like somebody welded it in place. A new master cylinder and the brakes have been normal ever since. I still have the original Booster on my power brakes.
Before the "failure" of the master cylinder I had to warn UN-suspecting drivers that the brakes were HYPER-Sensitive. I watched a Chevrolet dealer's Corvette Tech as he drove my C3 and almost put himself thru the windshield when he braked really hard. I told him to be careful but the lure of the 427 was too much for the man and he went flying through their parking area and then had to stop. Nobody could ever explain "How" a master cylinder can get "more sensitive" than normal. I am just glad to have normally functioning brakes again.
That sounds more like a master cylinder as I had a master cylinder that was really sensitive and then one day it just "locked up" (like there was a brick under the brake pedal) while I was at 70 mph in my BB C3. Fortunately I have a four speed and was able to slow the car down with that. I do believe a few hairs on my head turned grey after that experience, it was terrifying to be entering a Clover leaf at 70 mph when the posted speed was 20 mph.
The master cylinder was locked up like somebody welded it in place. A new master cylinder and the brakes have been normal ever since. I still have the original Booster on my power brakes.
Before the "failure" of the master cylinder I had to warn UN-suspecting drivers that the brakes were HYPER-Sensitive. I watched a Chevrolet dealer's Corvette Tech as he drove my C3 and almost put himself thru the windshield when he braked really hard. I told him to be careful but the lure of the 427 was too much for the man and he went flying through their parking area and then had to stop. Nobody could ever explain "How" a master cylinder can get "more sensitive" than normal. I am just glad to have normally functioning brakes again.
