MGB Register Forum

The remote servo (Lockheed type) has just failed after circa 50 years on my1972 BGT. It was about the only component which had never been replaced.

I started up the BGT after a long Winter slumber and was greeted by clouds of white smoke which eventually cleared. I didn't realise what it was, as all seemed well.

But today, several days later, I noticed the master cylinder was almost empty. The penny dropped at once! I did then refill the master cylinder and - no white smoke and a firm brake pedal. So it really appeared as if the servo leak had cured itself?
The servo pipe to the inlet manifold was wet inside with brake fluid, so no doubt what had happened.

I have ordered a replacement servo, but am really puzzled as to how the leak of fluid has somehow ceased? It will be replaced before I drive it again!

Ian F

Could a seal have dried out allowing the fluid to escape, after which, you gave it some more fluid and that’s caused the seal to swell once more?

I repair vintage watches and am well aware of the re-sealing properties of a little silicone on an aged rubber seal

Something like that is the only possible explanation Dick.

Not safe to rely on it staying fixed though, so it's out of the B now and my new one should be here soon.

Ian F

The remote servo sucking the master cylinder dry is not a unique experience. On Victor Smith's V8 website he has heard of several cars which have suddenly had no brakes at all, the driver not having noticed anything untoward up to that bottom clenching moment. My '71 MGB has no servo and the brakes are fine. Would I fit one - definitely not.

I probably wouldn't fit one if my BGT didn't have one from the factory, but I will keep it as it left Abingdon. Strangely enough, after the white smoke cleared the brakes still worked fine - I was lucky I guess, I took it on a 3 mile test drive as the first of the year. It was several days later that I noticed the nearly empty master cylinder.
Hopefully this new OE servo will last as long as that original one!

Ian F