RE: Need cruise vacuum pump - 85 4KSQ

["Buchholz, Steven" <Steven.Buchholz@kla-tencor.com>]

... I've never seen this myself, but if it appears that the cruise
control is attempting to hold speed, yet it appears to slowly decelerate
over time, then the pump is the most likely suspect, but it still may be
that the actuator or switches might have a slow leak.  Have you tried
seeing if the system can hold a vacuum?  You'll have to seal off the
line to the pump ... because it's supposed to be able to leak.  Push in
the throttle body actuator and hold it there while you pinch off the
vacuum line to the pump.  If the actuator returns to the idle position
you've still got a leak somewhere.  Since you've replaced the lines it
can only be the actuator or one of the vacuum switches on the brake or
clutch.  

One final thought, it might be that the release valve in the pump itself
may be leaking ... you might want to put a couple drops of light oil in
the inlet that the hose connects to and then blow a bit of air through
the passage to get it to the valve seals ... what the hey, the pump's
already bad!

HTH!
Steve Buchholz
San Jose, CA (USA)

> ----------
> Well, I've replaced all the vacuum lines on my cruise system and it
> still won't
> hold a speed - so I'm contemplating trying to replace the cruise
> vacuum
> pump.... anyone have one for an '85 4KSQ that I can throw in my car?
>