Re: W/S washer pump

[zm@mhcnet.att.com (Zafer Mehmood [209])]

> 
> The windshield washer on my 87 5000SQ was getting weak in its squirting
> ability. After some poking around I removed the in-line check valve at the
> resevoir and voila I could wash the w/s again. Either the checkvalve is
> bad or the motor/pump is weak (I'm theorizing here).  Anyone else had a
> similar problem?  ...and, what is that valve for anyway (it seems to work
> ok w/o it) ? 
> 

I had the same problem in my '87 5000TQ and I did exactly what you did -
got rid of the check valve. This valve prevents the washer solvent from
flowing back into the reservoir. So the downside is that the spraying
action is delayed until the solvent gets pumped up again. This could
cause early deterioration of the wiper blade and possible scratches
on the windshield if there is dust, dirt buildup since the wiper starts
moving as soon as you pull the lever.

I think its a weak motor, not the check valve that causes this problem.
You can test the check-valve by blowing through it - it should allow flow
only in the direction of the arrow. I went to buy a new valve at the Audi
dealer and found that the new valve had much higher resistance to flow
than the older one - so it wouldn't have helped. So I didn't buy it and
am managing with no check valve.

Zafer

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Zafer Mehmood				   AT&T Bell Laboratories
zm@mhcnet.att.com			   Murray Hill, NJ