Date: Mon, 25 Sep 2017 18:40:19 -0700
Reply-To: Stuart MacMillan <stuartmacm@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Stuart MacMillan <stuartmacm@GMAIL.COM>
Subject: Re: Stumble and Loss of Brake Pressure Heading Up a Pass
In-Reply-To: <CAKLYf13sps=PvYExZO0qWd7DAud7BN6CSG7Ab4aV+TP89soiVA@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"
The standard test for the booster is to depress the brake pedal and start the engine. Pedal should drop a bit on startup. Like Dennis said, you might have a stuck brake caliper piston. The friction could cause the fluid to boil (or absorbed water to vaporize) which results in loss of braking. Time to have the brakes checked.
Stuart
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of Ryan Perry
Sent: Monday, September 25, 2017 5:55 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Stumble and Loss of Brake Pressure Heading Up a Pass
Thanks Dennis, checked the level and was at max. I can't say how old the brake fluid is so maybe it's time to change it?
Is there a definitive test anyone knows for master cylinder and brake booster?
Thanks
Ryan
On Mon, Sep 25, 2017, 3:27 PM Dennis Haynes <d23haynes57@hotmail.com> wrote:
> Check master cylinder fluid level. Combination bad cylinder and brake
> booster can let engine vacuum suck the fluid out of the master.
> Next would be brakes dragging or otherwise overheated and you vapor
> locked the brakes. Problem could be compounded by the fluid being old
> and saturated with water.
>
> Dennis
>
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On
> Behalf Of Ryan Perry
> Sent: Monday, September 25, 2017 3:14 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Stumble and Loss of Brake Pressure Heading Up a Pass
>
> This one is new for me, taking it to the collective brain trust!
>
> '84 Manual with a newly installed 2.2l GoWesty. Runs fine in all
> normal driving conditions. When heading up a pass for camping this
> weekend, think Western NC, couple thousand feet elevation over 4 miles
> or so. The van was under moderately heavy load in 3rd gear, RPMs on
> the high side but nothing outrageous, was holding steady in power.
>
> About 4 mins in the power hiccups slightly then continues on. I had a
> bit of a corner so tapped the brakes lightly and find no pressure.
> Really weird. Made it to the top for a short flat and found I had to
> pump brakes to get pressure. This was short lived for a single
> application. As soon as I let off back to no pressure, had to pump
> again. Then back up the next section of the cut under similar load and
> had the same stumble at about 3-4min in then carries on fine. Top of
> that cut and the end of our trip out the van is running fine, though a
> bit hot as expected, but no brakes without pumping.
>
> Parked, camped, had a great time celebrating or 4th wedding anniversary.
> (Someday I'll show you all or vanagon wedding pics, you'll like them)
> Anyway, leave Sunday and brakes are fine, engine is fine.
>
> What do you think? Related? Coincidence? Vacuum line or booster? Fuel
> pressure or pump?
>
> Thanks for any ideas, i try to keep stopping at the top of my list of
> fixes!
>
> Ryan
> Asheville, NC
>
