Date: Sun, 5 Jul 2015 01:54:52 -0400
Reply-To: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Subject: Re: Low Brake Pedal, Caliper Piston Movement.
Content-Type: text/plain; charset="us-ascii"
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
-----Original Message-----
From: "Neil N" <musomuso@GMAIL.COM>
Sent: Saturday, July 4, 2015 3:24 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Low Brake Pedal, Caliper Piston Movement.
So I stopped by my sweat shop yesterday (garage on hot day) and
checked-readjusted rear brakes several times. 1 Wheel required a
*minor* adjustment. Contrary to my earlier post, my adjustment method:
check, adjust, check, adjust (several times), push brake pedal several times
engine off and on then do a final recheck.
(I now understand that even if the wheel cylinder pistons are held out by
internal spring, they simply get held out to the shoe position as
established by adjuster bar and stronger return springs) At this point, 1
click of adjuster wheel up/down will cause wheel to noticeably slow or let
brake shoes drag slightly. They are set to "drag slightly". Turning wheel by
hand, I can feel a noticeable difference between these two settings.
Settings remained the same after brief road test.
With e-brake set, wheels off ground, I can final torque wheels.
E-brake was checked
with drums off.
Initially, the pedal felt as it usually did; pushing super hard, I could
hear and feel it bottom out as it. Slamming on brakes at ~ 20 MPH, fronts
lock leaving an equal skid patch. No marks from rear tires. I didn't note if
pedal went to floor but it certainly had enough pressure to make brakes
work.
Driving bus around, pedal height increased but I assume it may or may not
decrease after sitting unused. The odd part is that when pedal is higher,
coasting to a stop in neutral, I swear the sound of the shoes and/or pads
rubbing, is louder. (at idle, engine is quieter than
stock)
Contrary to my past history, I'm loath to throw parts at this but will
replace brake master cylinder..... again. I have a good near new spare
(1000 miles?) I'm tempted to use for experimental purposes but will likely
opt for the van-cafe "German" part. I'll contact them to see if it's in fact
made in Germany.
I have a spare pressure equalizer from my '85 but it may not work given
angles involved, mount holes. Image: http://tinyurl.com/pvn5lea OEM part as
installed, lower LH: http://tinyurl.com/okjlqwj
The bus is driveable as-is but I feel it can be improved.
Neil.
On 6/27/15, Neil N <musomuso@gmail.com> wrote:
> I'll adjust the shoes again and report back.
--
Neil n
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