Miracuously loosing brake fluid

[Peter B.]

Hello,

from time to time I seem to loose brake fluid from the driver?s side brake fluid bottle only (rhd). Sometimes half of it in two weeks and then none in two months, always with the same driving profile (speed, duration, brake usage etc.) There are no visible leaks, no fluid on the floor in my garage. Front calipers are 1 1/2 year old, rear ones age unknown to me, but all serviced regularly by an jaguar specialist. Complete system has been pressure tested etc.

I?ve heard from brake servoes, being filled with missing brake fluid, that needed to be rebuild. How can I make sure where it goes? And any ideas why its always missing in the bottle on drivers side only?
As the fluid is quite agressive, at least to paint, do I have to fear any follow up damages, when it is in the brake servo for a longer period of time?

Many thanks for advise

Peter

[Heuer]

Peter

Known problem is fluid leaking into the vacuum reservoir caused by a faulty valve on the master cylinder. Take the reservoir (big black lozenge shaped thing) off and check to see if it has fluid in it. If it has you need to replace the master cylinder or, if you can get it as a separate item, the valve on the end (white round nylon thing). It is the valve that sticks and some restorers put a stronger return spring in there as a precaution. You MUST get it sorted before taking the car out again as if the reservoir becomes full you could lose servo assistance.

[p1vickers]

Peter

When this happened to my car, I found the fluid was leaking from the master cylinder into the drivers side footwell. It soaked the bulkhead sound deadening material and carpets on that side. Just shine a torch on the brake pedal push rod and check if the back of the cylinder is wet.

Regards

Peter
67 S1 2+2

[Moeregaard]

I've neverh had fluid leak into the vacuum reservoir, but I have had it drain into the servo chamber. It will do this for a long time before it reaches a level that will allow it to be drawn into the manifold. You will not believe how much smoke this makes.

When I first experienced this phenomenon, the servo failure was followed minutes later by the complete failure of the master cylinder. Being 22 and relatively stupid at the time, I threaded my way through thirty miles of Los Angeles traffic, timing my approach to intersections and using the handbrake when I did have to stop.

My recommendation? Replace every rubber component in the braking system when one begins to fail.