Brake problems - poor responding
Thread Starter
Heel & Toe
Joined: Jul 2007
Posts: 15
Likes: 0
Brake problems - poor responding
Have a 69 big block without PB. Replaced mastercyl.,hoses and all 4 calipters (changed to o-ring type) as they were leaking. After bleading ( for a very long time to get rid of all the air) I do now have a good and strong pedal. Taking the car for a testride-making almost panic-brake, I was very surpriced to experience that the car did not respond quick like it should, but came to a stop very poorly. Could there be something wrong with the lines or prop.valve - these are the only parts in the entire system not replaced?
Thread Starter
Heel & Toe
Joined: Jul 2007
Posts: 15
Likes: 0
Sorry, but that`s not part of the problem. I`ve had the -69 for 10 years, and the brakes have been VERY sharp until I had to replace the master cylinder due to leaks. Thanks.
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Usually a bad new master cylinder or air in the lines would leave you with a soft or mushy pedal. I suspect you might still have firmness if the master has failed, but first I might suggest you pull the wheels and inspect everything very carefully. Make sure all rotors are spinning true and that you don't have fronts on back or backs on front and make sure all your soft lines are healthy looking and not swollen.
Does the red BRAKE light ever come on even though the fluid level is topped off?
Burning Brakes
Joined: Aug 2007
Posts: 1,173
Likes: 1
From: Liberty Missouri
Is it possible that you have a master cylinder out of a power break car? That could explain a bunch. It just seems funny the problems started when you changed the MC
Thread Starter
Heel & Toe
Joined: Jul 2007
Posts: 15
Likes: 0
Usually a bad new master cylinder or air in the lines would leave you with a soft or mushy pedal. I suspect you might still have firmness if the master has failed, but first I might suggest you pull the wheels and inspect everything very carefully. Make sure all rotors are spinning true and that you don't have fronts on back or backs on front and make sure all your soft lines are healthy looking and not swollen.
Does the red BRAKE light ever come on even though the fluid level is topped off?
Does the red BRAKE light ever come on even though the fluid level is topped off?
I have not been driving the car since, just testing the brakes around my garage.
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Thread Starter
Heel & Toe
Joined: Jul 2007
Posts: 15
Likes: 0
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
I'm kind of wondering about the P-valve or maybe if there is a blockage to one of the circuits. When you have the car up on jack stands, turn the wheels by hand and have someone stomp the pedal to make sure you have braking force on all wheels.
Le Mans Master
Joined: Mar 2001
Posts: 6,640
Likes: 287
From: Ann Arbor Michigan
There is no Prop valve on a 69', just the diff warning valve. Did you happen to replace the brake shoes with a "performance" type lining? If so, they need some heat to work well. Also, take the car out and run a few light decel stops to burnish the brakes. Don't make any high decel stops until you do this.
Thread Starter
Heel & Toe
Joined: Jul 2007
Posts: 15
Likes: 0
I`ll try this, just to be sure
Thread Starter
Heel & Toe
Joined: Jul 2007
Posts: 15
Likes: 0
There is no Prop valve on a 69', just the diff warning valve. Did you happen to replace the brake shoes with a "performance" type lining? If so, they need some heat to work well. Also, take the car out and run a few light decel stops to burnish the brakes. Don't make any high decel stops until you do this.