Date: Sun, 5 Jul 2015 00:14:27 -0700
Reply-To: Neil N <musomuso@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Neil N <musomuso@GMAIL.COM>
Subject: Re: Low Brake Pedal, Caliper Piston Movement.
In-Reply-To: <BAY405-EAS5608772DB56E7529268DDDA0940@phx.gbl>
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Excellent info as always Dennis.
Thank you for taking to to write that.
The pedal does indeed sink a little when doing as you suggest.
The booster itself is less than 10 years old and has seen no
fluid in it. If memory serves, the pedal height and feel is ok
engine off.
I will adjust the shoes accordingly. I didn't know about the new vs
already worn shoe aspect.
My other thought is that maybe something is wrong with the calipers.
Could the calipers have been rebuilt (poorly) in such a way that the
O-ring at piston is making the piston retract too far back?
The pistons move freely. Calipers don't leak and are about 5-7 years old.
On 7/4/15, Dennis Haynes <d23haynes57@hotmail.com> wrote:
> Properly set up the rear brakes should not be adjusted to "drag". A little
> rub just to get new stuff seated may be OK but when released they should be
> completely free. Having them rub can be problematic during a long trip or
> after heavy stopping. The shoes can heat up and expand causing the drag to
> get even worse and the cycle will continue until the brakes lock up and at
> that point the cylinders, shoes, and drums will be damaged.
>
> Another possibility for a low pedal is the brake booster. Try pumping the
> brakes with the engine off. If the pedal is hard then the hydraulics are
> OK.
> Push on the pedal and ten start the engine. The pedal should pull down
> slightly, about an inch or so. It is possible the "stop" you are feeling is
> the limit in the brake booster.
>
> Keep in mind that new shoes and even pads will give a softer pedal until
> they really get seated. If you didn't replace or re-surface the rotors they
> may never seat properly. As hard as front pads seem new they compress more
> than worn ones and until you get the transfer film set up on the rotors
> they
> won't make the same friction. Drum brakes take longer.
>
> Dennis
>
--
Neil n
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