Jaguar xj6 1992 Brakebooster failure

Hello from Finland!

Bought My brothers Jaguar xj6 and it has problems with brakebooster…

Booster worked fine for 2 days, but The Brake warning light was going on and off, then it stayed on untill now but everything was working fine.

Just today while i was driving The brakebooster disapeared… Any idea what could cause The problem?

Was reading about The accumulator system could fail. Where shoud i Start looking?


Hi and welcome, moved to XJ40 , good luck!

Hello Mico, and welcome to Jag-lovers.

There is a wealth of information on the Jag-lovers site. The current site ( contains the posts to the forums and incorporates the archived forum posts from the previous site ( There are, on the ‘old’ site some eBooks that contain valuable information. There is an overview of the XJ40 Teves brake system in section 7.4.2 of the eBook found here:

Cause of this problem was a faulty abs relay!

Cost me only 10euros to fix

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