So I spent the other day at the auto hobby shop at the nearby Army base with
the van on the lift doing exhaust and suspension work. Here's what I found
with the brake system:

The rear brakes look great. Slightest amount of wear on the shoes (PO had
said they were replaced within the past year). The drum looked good visually
and the outside surface looked fairly fresh. I didn't have a micrometer to
measure the drums, but given they were replaced within the last year
(according to PO), I have no reason to doubt that they're within spec.

There was a large amount of brake dust (about 4 or 5 teaspoons) inside the
drum area on both sides. Not sure what would have caused this.

The seals on the brake cylinders looked okay. One of them showed signs of a
leak when I was vacuuming out the brake dust, but I think that might have
been because I had the hose right over one of the brake cylinder seals. It
was just enough brake fluid to moisten the seal/cylinder area. I cleaned it
up and wiped away the moister and there appeared to be no more leak (pumped
the brakes to double check). Could be the beginning of a failing wheel
cylinder seal, but not sure.

One other note: After I topped off the master cylinder resevoir the other
day and the brake pedal returned to normal height, I blead the brakes and
got the tiniest amount of air out. Now the pedal is the correct height and
not squishy.

I'm starting to think that the most likely cause of the brake pedal
bottoming out might have been a rear wheel cylinder seal failing and
allowing air in/fluid out.

On Thu, Feb 24, 2011 at 12:20 AM, Scott Daniel - Turbovans <
scottdaniel@turbovans.com> wrote:

> Hi,
> yes, it just 'floats' almost in the two rubber grommet things.
> So normal that you can rock it side to side ..like up to half an inch total
> travel.
>
> if you haven't seen inside the rear brakes , I'd do that.
> the two most likely places to leak are rear wheel cylinders and master
> cylinder.
>
> it is very easy for an old master cylinder to leak internally ..
> not seal from chamber to chamber ....
> that can equal low pedal with no external leaking.
>
> or as you were thinking ..air getting in somehow ..
> though I wouldn't think at the res grommet things. ..
> good thinking though for you to consider that.
>
> Scott
> www.turbovans.com
>
>