Date:         Fri, 21 Mar 1997 06:46:03 -0800
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         "Shawn & Janis Wright" <vwnut@smuslabs.smus.bc.ca>
Subject:      Re: DOT5 fluid (Was: 68-79 rear brake parts info)

> > After all the work you go through painting your backing plates, replacing
> > wheel cylinders etc., you might want to take Bob Hoover's advice and switch
> > to DOT 5 brake fluid.  Apparently the DOT 5 doesn't contain the paint eating
> > Methyl methanol that your typical brake fluid has.
> > 
> 
> If Hoover reccs silicone fluid, he could be DEAD wrong.  Something 
> I've found finally working as a "rocket scientist" is that some 
> O-ring and seal formulations work with silicone based fluids, others 
> work with glycols.  Sometimes they work with both, sometimes 
> they do not and you DIE.  Just because OEM German might have been OK 
> does not mean neccesarily that that Brazilian seal is up to it after 
> a couple of years.  Just a thought, use quality DOT4, and bleed 
> regularly, change every 2, that is what VW recced, or be very sure 

I'm almost certain that BOTH my VW manuals say NOT to use DOT 5, 
which is reason enough for me. If you regularly boil high temp DOT4 
fluid, there's something wrong with your brakes or your driving. I 
would suspect allowing prolonged higher temps with DOT 5 will only 
cause something else to fail (like seals), which aren't likely to 
give as much warning as brake fade does.
My Corrado used DOT4 and had no trouble with brake fade, even driven 
hard and fast.

Just my .02.

Shawn & Janis Wright
'88 Westy (338k) '85 Jetta TD (367k)
VWnut@smus.bc.ca (swright@smus.bc.ca)
http://www.islandnet.com/~swright/vw.html