[Healeys] BJ8 Brakes not releasing

[Bob Spidell]

Having thought about it a bit more, I'd wager a C-note--Canadian or American dollars, whichever is worth more today--that the problem is with the seal on the inner wall of the large vacuum/gas cylinder. I suspect the dry lubricant has been worn down--or the rubber seal has become brittle or sticky--and this causes the gas piston to not be able to retract after braking (it does have a large spring under it). Since your symptoms seemed to have come on gradually this is logical. Actually, the seal is formed by a leather seal, and the rubber ring is there to keep pressure on the leather seal. 

Usually, the servos fail when the seal on the gas piston shaft--known as a 'gland seal'--becomes brittle and/or breaks causing the servo to suck brake fluid into the vacuum cylinder (if you're losing brake fluid mysteriously you may find it in the gas cylinder). For this reason--and general principles--if you choose to rebuild yourself you should do a full rebuild with a kit (even though, theoretically, you may be able to get by with just re-coating the inside of the gas cylinder with a dry lubricant). 

I used an older version of this product, and it has worked well for many years: 

http://www.associatedindustriesinc.com/store/solid-and-dry-film-lubricants/sandstrom-28a-solid-film-lubricant/ 

Bob 




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Bob Spidell - San Jose, CA 

----- Original Message -----


Our BJ8's (Phase II) brakes are not releasing properly. 
... 

Geoff and Carol 
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