Date: Tue, 17 Aug 2010 12:32:08 -0700
Reply-To: BenT Syncro <syncro@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: BenT Syncro <syncro@GMAIL.COM>
Subject: Re: brake question
In-Reply-To: <386AD820-66DB-4276-9647-ACEF7C496BE7@sheilah.org>
Content-Type: text/plain; charset=us-ascii
Hello Ms. Rogers,
You may have been experiencing brake fade. It's not uncommon after using the brakes for an extended period over mountain grades. The rear brake drums may have warmed up enough to the point that the drum becomes bell-shaped and starts to lose contact except at the outer edges. Good argument for rear disc brakes.
No disrespect to your mechanic but did he REALLY drive the vehicle for 30 minutes and use the brakes? Dis he charge you for that time?
An air bubble in the system could also exhibit such a symptom. Or even a leak. I assume you're not finding any of the above. These sort of problems don't usually resolve themselves except for maybe air in the system.
Don't change the master cylinder just on suspicion that it's bad unless you have the spare cash. It's a rather expensive guess.
Glad to know your baby is able to take you around now. Not so happy that she's occasionally not able to stop her enthusiasm.
Regards,
BenT
On Aug 17, 2010, at 12:04 PM, Sheilah Rogers <sheilah@SHEILAH.ORG> wrote:
> 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.
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