I’m loosing master brake fluid.

[elliottS]

Loss of brake fluid from the master brake front brakes sys. Trying to trouble shot this I pumped up the brakes with the pedal. When engine started much white smoke belched from exhaust. I get no smoke if pedal not pumped. Could brake fluid finding it’s way into the intake from pumping the pedal many times, but with engine off it accumulates enough to cause noticeable smoke?? Leaky vacuumed assist bellows? Or HOW?

[MarekH]

The vacuum for the "vacuum assist" part of the braking system is generated by running the engine.

There is a seal which has failed somewhere between the parts of the brake system kept under vacuum and the hydraulic part of the brake system.

The Repair and Operations Manual has detailed drawings of how they link up.

kind regrds
Marek

[christopher storey]

It will be seal failure in the hydraulic cylinder attached to the front of the servo unit . This allows fluid to enter the servo. You are likely to find when you remove it that it has a large collection of fluid inside it

[elliottS]

Thanks for the replies to my problem. Can I assume the brake servo is the problem of passing fluid to the intake? Or is there any other path for the fluid that I could check. I see that there is a check valve in the system too.

A rebuild kit of seals is about $60 for the servo so not to bad...New servo is about $1000.

Thank to all my brothers across the pond for the help. I am still learning Jaguar.

Elliott

[Joes66]

£1000 ?
You can pick up a complete new servo and master cylinder for about £150.00 here in the uk
Have you checked around the usuals or e bay?
Not really worth rebuilding it
Just put a new one on
Joe

[Adamski]

Little word of warning,I have heard that replacements are not always functioning correctly so keep your old ones. I have rebuilt mine and all is well. There have been issues on the little valve at end of master cylinder causing the brakes to lock on.