Sticking brakes / Vapour lock

[Lucky82]

Hello all,

After a pretty rigourous weekend of hilly country driving an issue with the brakes developed.

When driving from cold, the brakes work fine, servo doing its job etc. Then, intermittently the brake pedal becomes very hard (as if the vacuum system has failed) but the brakes are also engaged (Even the brake light stays on when the pedal is released). Continuing after this point leads to burning brakes pads/shoes.

i always take care to engine brake as much as possible and don't race down hills only to hard brake before a bend etc.

Brake calipers and slave cylinders at rear are new. Brake fluid less than an month old. Master cylinder fine also.

So, I've been researching and a vapour lock due to the hygroscopic nature of brake fluid seems to fit the symptoms. However, due to the age of the fluid I was wondering was would accelerate this issue. The entire system including lines and reservoir tank had been sat empty for a while whilst carrying out repairs so maybe condensation formed that way?

Would appreciate your thoughts if there is something I've done incorrectly or anything I should be aware of. Don't want to be driving if any danger of total brake failure....

Many thanks,

P

[a1winchester]

I had something similar happen on an old Ford Escort estate I had years ago.
The disc brake pads weren't releasing properly, and were constantly rubbing a little on the discs, generating heat and causing the symptoms you described.
The solution was to clean up the pins that hold the pads in place, and lubricate the pins a little to allow the pads to clear the dscs when the brakes are released.

[kevtherev]

Brake fluid must be changed every two years.
Worn discs will cause brake fade (that you experienced)
I was quite surprised at the thickness of the new disc compared to my old one.