Brake servo noise

[M4rk]

Hi All,
On our journey down to Silverstone my passenger noticed he could feel and hear noise from the brake servo when applying the brakes. The brakes work fine and the servo unit was replaced a few years ago, I have a feeling it's always been this way and may be because the servo is bolted directly to the bulkhead.

Just thought I'd ask for some feedback, is this usual for a series 2?

Cheers

Mark

[christopher storey]

Absolutely characteristic : the servo is bolted to the left hand footboard and the knock each time it is operated can be heard if there is no background noise ( such as when the engine is switched off ) and felt if your feet are pressed against the footboard. If you try pressing the pedal with the engine off you will hear the knock gradually diminishing in volume as the vacuum dissipates with each pedal operation

[M4rk]

Thanks Christopher for putting my mind at rest

[Stevejaguar]

Hi I seem to have a similar but opposite problem since replacing the master cylinder and servo . Switch the engine off and press the brake. There is no 'clunk' at all, let alone one that diminishes at each push of the pedal as it used to do.
Not had chance to test the brakes yet other than backing the car out of the garage. They worked OK then.
Pedal is solid , vac pipes are correct way round, one way valve on reservoir is working fine. No vac leaks.

Any ideas ?
Steve

[christopher storey]

A bit strange, Steve. The key may lie in your solid pedal. Generally speaking, with the servo "empty" i.e the pedal having been pressed quite a few times with the engine off, the pedal should be solid. If with the pedal pressed down you then start the engine, you should feel the pedal give a little and become slightly squashy . If that is not happening then it suggests that you are not getting vacuum to the servo itself

[Stevejaguar]

Hi, thats how the pedal used to be. Start the engine with your foot on the pedal and the pedal drop slightly. It doesnt do that any more. I am certain that I have vacuum to the servo.
Servo problem ?
Steve

[christopher storey]

Have you checked out the air valve on the front of the main master cylinder? It is also worth bypassing the reservoir and the one way valve and seeing if that makes a difference