Brake servo leak?

[soul4t]

1990 M40 engine

With the engine running if I pump the brake pedal, you can hear hissing from the passenger footwell...there is a slight tear from the grey consatina (err spelling) boot where the rod goes through the bulkhead and into the back of the servo? This seems to be where air is escaping... As well as the hissing, the idle suffers, badly rattling...even bad when I just hold the pedal down.

I've had a slightly bad idle for years, cold running is poor. Just wondering if this has been contributing...

Any thoughts? Many Thanks!

[Yeti]

mines the same with hissing lol but a test to see if the servo is fooked is pump the pedal till its hard with the engine off. then whilst pressing the pedal turn the car on the pedal should go down if not its dead

[soul4t]

Ah cool, yea I've done the test and it passes... Cheers!