'88 5KSQ (Type 44) Brake Problems

[Joshua Van Tol]

>The brake pedal on my '88 5KSQ will slowly go to or near the floor 
>if I hold pressure on it.  The warning light switch on the servo for 
>the Autocheck system is disabled.  The car has a new pump and 
>pressure accumulator ("bomb").  In a normal car, I would suspect the 
>master cylinder.  But what is the "brake servo"?  That is the thing 
>between the pedal and the master cylinder.  What does it do?
>
>At about 120K miles, I am ready to replace the master cylinder.  No 
>rebuilds for this critical part.  Should I also replace the servo?

The servo functions just like a vacuum operated brake booster. You've 
got a bad master cylinder. A failed servo should either leak, or 
simply fail to provide braking assist.
-- 
Joshua Van Tol -- josh at spiny.com