Brake pedal feels like a rock and very difficult to stop. I assuming it's the booster but as I'm not much of a brake technician I would appeciate any advice on troubleshooting the system before I tear it apart. What kind of vacuum should I expect to the booster? Mostly stock 428 with an old Crane CCH-280 cam. Car is a 15 year old resto with about 4-5k miles since all was replaced or rebuilt. Thanks in advance...
Sounds like the booster has given up. Same thing happened with my 67 in Sweden this summer. When you press the brake panel does the car want to die? Is there a noise (pssss) inside the car when you press the brake pedal? /Texas Swede
Texas Swede- Have not noticed the Hiss inside the car or the engine stalling when pedal is depressed. I guess these could happen with loosing vacuum through the booster? Thanks
The noise, hissing didn't came on immediately but after driving the car for a while. It started to run rough when I pressed on the pedal until I capped the hose. Have you checked your hose? Thre may be a crack in it. Loosing vacuum through the booster would do what I experienced. Texas Swede
Before you start replacing things, I'd suggest checking the vacuum line from the manifold to the booster. If it's old and cracked or damaged, that could do it. Good luck, Josh
Take the vacuum hose off that goes between the intake and the booster. Once you have the hose off look at the inside of the hose with age the inside of the hose collapse . override
Found this online - HARD BRAKE PEDAL Lack of power assist may be due to low engine vacuum, a leaky vacuum hose or a defective booster. Sometimes a faulty check valve will allow vacuum to bleed out of the booster causing a hard pedal when the brakes are applied. This condition can be diagnosed by starting the engine (to build vacuum), shutting it off, waiting four or five minutes, then trying the brakes to see if there is power assist. No assist means a new check valve is needed. A quick way to check the vacuum booster is to pump the brake pedal several times with the engine off to bleed off any vacuum that may still be in the unit. Then hold your foot on the pedal and start the engine. If the booster is working, the amount of effort required to hold the pedal should drop and the pedal itself may depress slightly. If nothing happens and the vacuum connections to the booster unit are okay, a new booster is needed (the vacuum hose should be replaced, too). Good Luck
Have you checked all your lines to make sure nothings split? When was the last time you flushed all the fluids out? Depending on what type of fluid youre using it tends to pick up water, it might be a good idea to flush out the entire system.
