Re: 86 4kcsq vacuum pump

["Bruce Bell" <bbell@bbell.com>]

Phil, I took a good look at this when I changed the cam on my car.  The
lobe on the cam is just an eccentric as you would find for a cam driven
fuel pump .  I suspect your observation is very plausible.

Ron, I know several very inelligent folks on this list have either removed
the actuating rod or the whole pump with no adverse effects.  I'm a little
old fashioned and am reluctant to do this to mine. I too had the nasty
ticking at one time; but, it was after a period of negligence on my part
when I hadn't changed oil as often as I should have. I change oil
frequently now (well most of the time) and at 190-200,000 miles there is no
ticking from either my vacuum pump or lifters.  The pump gets its
lubrication from a splash system - splash the oil in, splash the oil out.
If it isn't clean ,the rod gets a little gummy and sticks so very slightly
- doesn't take much for that hard steel rod to make a lot of noise when
slapping against a billet cam.  BTW I checked on my car and there was no
clearence between the rod and the cam lobe.

Best advice - keep your oil clean and avoid any thing "gummy".

----------
> From: Phil Payne <quk@sievers.com>
> To: quattro@coimbra.ans.net
> Subject: 86 4kcsq vacuum pump 
> Date: Monday, May 12, 1997 12:14 PM
> 
> In message <863453065@triad1.com> rwoods@triad1.com (Ron Woods) writes:
> 
> > As a matter of fact, there are only TWO nuts holding this pump onto the
head
> > near the front opposite the intake side. Turns out, once you remove the
two
> > nuts, the entire pump will come right off. Actually the push rod inside
had
> > enough pressure on it that it pushed the pump off as I removed the
nuts. There
> > is a rubber o-ring seal recessed into the pump, which I did not have a
new one.
> 
> Fascinating.  It sounds very much like this pump is mounted using the
fittings 
> originally cast into the head for the fuel pump in the early carburretor 
> models.
> 
> This fuel pump was secured by two large Allen screws.  The O-ring went
into 
> a recess in the pump - not circular, but a kind of 
>  
>                     ___
>                    (   )
>                     ) (
>                    (___)
>                     
> A long lever protruded from the pump and rested on the underside of the
cam.  I 
> wonder if the same lobe is used to drive your vacuum pumps?
> 
> As for ticking - the old fuel pump was a _horror_ for it.  You could
reduce the 
> problem by loosening the screws, exerting upward pressure on the pump,
and 
> retightening the screws.  But it started again within a month.
>  
> --
>  Phil Payne
>  phil@sievers.com
>  Committee Member, UK Audi [ur-]quattro Owners Club