Brake Master cylinder

[Jimb]

Can someone please explain how a brake master cylinder fails when it does fail as well as a brake booster?

Thanks,

Jim

[DieselSpider]

Can someone please explain how a brake master cylinder fails when it does fail as well as a brake booster?

Thanks,

Jim

Most common cause of brake master cylinder failure is not flushing the brake fluid out and replacing it with fresh from a new bottle of fluid that has not had the seal broken until the moment your about to refill the reservoir. Brake fluid is hydroscopic and with the nature of the brake reservoir cap with the float used on our cars which allows outside air and humidity into the reservoir being as it is the 2 year brake fluid flush and refill cycle becomes a more critical service the needs to be kept up with.

Brake boosters can last a good long time before the diaphragm develops cracks or the metal housing rusts out and starts leaking however if you don't take care of the brake fluid flushes then when the master cylinder fails brake fluid can leak into the booster damaging the diaphragm leading to premature failure.

To me most replacement of brake components aside from brake pad or shoe changes come about from lack of maintenance regarding brake fluid flushes and the lubrication of the caliper guides and mounts using a high quality brake grease. The sliding guides and mounts need to be cleaned and greased every time the brake pads are replaced and at every brake flush.

[Jimb]

VERY helpfull!

Thanks,
Jim

[Spider951]

As for the brake booster, IIRC there is a vacuum line to it from the intake manifold. That vac hose needs to be replaced periodically.

[Jimb]

I discovered the brake booster check valve was not screwed tightly into the rubber bushing on the booster which has been the cause of loss of power and the feeling of severe brake drag while driving.
A very simple problem considering I was execting I needed a new brake booster.

Jim