The Vanagon requires Dot 4 brake fluid for its greater heat absorbing
capabilities.

On Thu, Aug 19, 2010 at 7:23 AM, Sheilah Rogers <sheilah@sheilah.org> wrote:

> Thanks everyone for all the info - so helpful!  :)
>
> So here's what I did:
>
> Ruled out brake fade since I imagine that by the time this happened, the
> brakes would have had plenty of time to cool down (~45min on mostly empty
> highway).
> There was no fluid loss when the mechanic checked.
> The mechanic ruled out air in the system stating that if that were the
> case, I should have been able to reproduce the problem more readily since
> it's a closed system and the air would have still been there.
> And the brakes working-failing-working did seem to suggest that master
> cylinder....
>
> (Unfortunately I did forget to ask him to bleed first for diagnostic
> reasons).
>
> But instead, I asked the mechanic to go ahead and replace the master
> cylinder (he says that's 2hours labor, fwiw, and hopefully you all agree
> that's more or less correct). He added that replacing the cylinder would
> inherently mean new fluid, therefore bleeding out, and fixing any potential
> air bubble issues too.
>
> I forgot to ask him (and youse) if anyone's using the new .4 over .3 brake
> fluid.... so I'm not sure what he put in. I just know that a friend who
> drives a (school) bus is using the newer .4 and recommended that (but he
> doesn't know VW).
>
> You all have made me think about pumping up the brakes. I've never thought
> anything of it. Certainly on downgrades I will (to prevent that brake
> fade)... Without knowing to do that, I'm pretty sure that I naturally would
> have tried to pump a few times, if for no other reason, hoping they'd engage
> in some way that the prior attempts hadn't caught. As for the brakes
> resuming their function, it did NOT happen immediately after pumping, more
> like 30minutes later.
>
> I suppose it's possible that brakes take more time than 30min to cool down
> (suggesting that it was brake fade and not the master cylinder...) Along
> similar lines, I suppose pumping the brake maybe returns functionality more
> quickly than the less pumping (and subsequent more time) to return
> functionality that I experienced (thereby suggesting that it was again, NOT
> the master cylinder). IF this is all true, than I might have replaced that
> sucka for nothing except a great lesson in brake fade, bleeding, and a brand
> new part. Hmph, we'll see, eh.
>
> Well, again, I hope I made the right decision, certainly couldn't make it
> without all your inputs. THANKS again!
>
> These vans sure like to be touched a lot...
>
> Sheilah
>
>
>
>
> >
> >
> > ________________________________
> > From: Sheilah Rogers <sheilah@SHEILAH.ORG>
> > To: vanagon@GERRY.VANAGON.COM
> > Sent: Tue, August 17, 2010 3:04:44 PM
> > Subject: brake question
> >
> > Howdy Folks,
> >
> > I'm wondering if I can bother the list's hive mind for some answers (that
> I
> > already could not find via the search tool)?
> >
> >
> > Basically something went weird with my brakes and my mechanic cannot
> reproduce
> > the problem.
> >
> >
> > So I was driving in ~80F weather, up and down a not so steep road but
> some
> > curves, about 30 minutes of said road was unpaved, van warmed up of
> course.
> > Brakes no problem. (not sure if weather matters but there it is.) I drove
> about
> > 45minutes total here.
> >
> > Then I got on the highway for another 45 minutes-ish. When I went to slow
> down a
> > bit, it was like my brake peddle wasn't responding with its normal sort
> of
> > push-back and instead, the brake pedal just dropped with no brake
> functionality
> > about 80% to the floor before it engaged. Once engaged, I could slow the
> van
> > down but of course I then had the pedal to the medal just to slow down a
> bit.
> >
> >
> > Being on a quiet highway I kept going, figured I'd pull over in a bigger
> town
> > and at least I can stop the van. But after 30minutes, the brake resumed
> normal
> > so I just continued driving to my mechanic's.
> >
> >
> > The next day he could not reproduce the problem, after warming up the
> van,
> > driving on hills, 30minutes or so. He says 50% chance it's the master
> cylinder.
> > But he's not sure (???) what else it would be since the brake fluid seems
> fine.
> >
> >
> > Anything else that should be ruled out or should I just have the master
> cylinder
> > replaced and hope it doesn't give out (50% chance?!) the next time I'm
> driving
> > on presumably worse mountain roads. I don't feel safe or comfortable with
> this
> > plan.
> >
> >
> > Does anyone want to weigh in at all?
> > Mucho thanks appreciated.
> >
> > Sheilah
> >
> > 1986 Westy water-cooled vanagon: Vanna White.
>
> ____________________________
> Sheilah Rogers, L.Ac.
> http://sheilah.org
> tel: 415/ 730-4144
>
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>

--
Jake

1984 Vanagon GL 1.9 WBX 'The Grey Van'
1986 Westy Weekender/2.5 SOHC Suby 'Dixie'

Crescent Beach, BC

www.thebassspa.com
www.crescentbeachguitar.com
http://subyjake.googlepages.com/mydixiedarlin%27