re: Vacuum Pump experiment

[Brendan Rudack <rudack@ucsub.Colorado.EDU>]

> >Wanting a definitive answer about the brake performance with a
> >"disabled" vacuum pump I took out the cam actuated rod.  After my
> >brief test drive I determined that the vacuum pump for the vacuum
> >assisted brakes has no functional pupose. 
> 
> Try running at about 115 mph (your car will do about 125 mph true, so
> you are not quite WFO) gently step on the brakes, bringing it down to
> 100, then open it back up... , and then stomp (Like your radar
> detector went off)  the brakes.  You will find your assit is
> significantly reduced becuase of low vacuum at high loads.  (And
> no, you don't get to know how I know this :) )  
>

I tried this from about 105 down to 85mph. On the throttle to ~95mph
again, brakes again and I was able to achieve threshold with no noticable
decrease in assist.  Hmmm....  I did notice that on the highway if you hit
thebrakes hard several times in a row the assist is gone.  I never tried
this with the pump functioning. Anyone care to try or hypothesize? 


Brendan Rudack
'88 90Q
Fenton Michigan USA

> -----------------------------------
> Allan D. Morris
> Phoenix, AZ
> allanm@primenet.com
> 1988 90Q
> -----------------------------------
>