Sinking brake pedal is either a fluid leak, or a bad master cylinder. If
the vac. booster was bad, you'd just have a harder time pressing the brake
pedal, it wouldn't sink.

At 09:33 PM 9/14/2006 -0400, Helmut Blong wrote:
>Thanks very much. Since your clever like that, what do you think is the most
>common cause for a sinking brake pedal? I figure vacuum as I am not losing
>brake fluid anywhere. It's a long run from engine to brake servo and I'd
>love to be able to narrow it down to common fault locations in that vacuum
>line.
>
>cheers,
>
>mordo
>
>---------- Forwarded message ----------
>From: Doug <vanagons@cox.net>
>Date: Sep 14, 2006 9:27 PM
>Subject: Re: Vacuum pump
>To: Helmut Blong <helmut.blong@gmail.com>
>
>Helmut,
>Yes, pump is for CC only, just follow the hose over to either the
>accumulator or actuator.
>Yes, vacuum from engine is ported through a one-way valve directly to
>the power brake servo.
>Good hunting,
>Doug in CT
>
>
>
>Helmut Blong wrote:
>>So, my search of Bentley and the archives seems to bear out that the
>>vacuum
>>pump is exclusively for the cruise control on my 90 Carat but I would
>>like
>>it if someone on list would confirm this.
>>
>>Ken Wilford's excellent posts on CC repair will be helpful when I finally
>>tackle that beast.
>>
>>Power brake servo uses engine vacuum exclusively?
>>
>>cheers,
>>
>>mordo