VTCI - Pacific Northwest Chapter

Interesting People Drive Interesting Cars

BRAKE TECH TIPS

The following are faulty brake booster symptoms,

1. Very hard pedal. You have to push like Hercules to stop.

2. Difference in idle or a rough idle while brake pedal is depressed

3. Brakes apply themselves.

4. Very sensitive pedal. You go flying through the windshield and you just barely touched the brake.

5. Brake pedal does not return.

The above, except #5, are always the brake booster The most common are #1 and #2 and they usually go hand in hand #4 is the next most common. A lot of cars have this problem and the owner is unaware of it. Its mostly in the 64 66 boosters. If you had a leaky brake master cylinder then check the booster to see if it filled up with brake fluid. It is very common for this to happen. It's sometimes easy to detect if this is occurring. Look under the master cylinder where it is attached to the booster. Do you see a trail of brake fluid down the booster'? Surprise!

 

The following are faulty master cylinder symptoms,

1. Your brakes will completely fail, no brakes at all, and then just as fast as they failed they will be OK again. Bad Master cylinder.

2. You’re at stop light with your foot on the pedal, the pedal slowly creeps to the floor and the car starts to move forward, change your master cylinder.

3. You have to pump the brakes to hold the car still.

 

Most cars with disc brakes, 65-66, have a proportioning valve. This valve can go bad or get plugged up and fail. When this happens you lose the use of the rear brakes. One way to detect this is to lift the car up and have somebody push the pedal while you turn the tires, look for excessive front pad wear and no rear shoe wear, big indication of a bad valve.

 

Change the Flex hoses when you do your next brake job. They are the weakest link in the brake system.