[urq] n00b question time...

Buchholz, Steven Steven.Buchholz at kla-tencor.com
Wed Nov 26 21:43:07 EST 2003

... well there is a vacuum reservoir after the check valve, so if you've run
the car any time recently you should hear that reservoir being relieved as
the switch position is changed ... or any lines become disconnected.  (NOTE,
you may not hear them with the engine running and the car buttoned up.)
While it still may be true that you've got a massive vacuum leak in the
dirty part of the car, you may want to start by checking the check valve and
vacuum reservoir first ... this supply is attached to the center fitting on
the vacuum control switch ... pull it off, attach a vacuum gauge and start
the car ... you should see vacuum build immediately (this will be true
whether the check valve is working or not.  Now shut off the engine and
watch the gauge ... it should hold vacuum for a very long time.  If it does,
then you know the check valve is OK, and the problem is downstream of the
control switch ... 

Steve B.
> I don't think I'm following...  I haven't noticed any 
> air-flowing sounds 
> either now or before when they worked right.  I was planning 
> on digging 
> around underneath the car tomorrow though, so if I'm lucky, I'll find 
> something obvious broken/disconnected.
> Mike
> Buchholz, Steven wrote:
> >Do you remember hearing any vacuum "sucking" sounds as you 
> did what you did
> >with the diff lock switch?  One common point of failure is 
> the check valve
> >(which has been known to cause issues when the actuators 
> attempt to switch
> >because boost rather than vacuum is applied!).  The vacuum 
> plumbing is
> >parallel to both center and rear lock actuators on the stock 
> '83 US models,
> >so if there is a diaphragm problem in one or the other, both can stop
> >working.  Fortunately the actuators aren't that difficult to 
> get to ... jack
> >up the left rear corner and remove the wheel and you'll have 
> all the access
> >you need ...
> >
> >Steve B.
> >San Jose, Kaleefohnia (USA)

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