Date: Wed, 24 Mar 2010 14:35:45 -0800
Reply-To: neil n <musomuso@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: neil n <musomuso@GMAIL.COM>
Subject: Neils Brakes: "What Me Worry?" (WAS: pedal feel)
Content-Type: text/plain; charset=ISO-8859-1
Hi all.
#1. THANKS! #2. I worry too much. #3 I'm too fussy (but I don'
think it's possible to be too fussy with brakes)
What I did: Morning, engine off, holding steering wheel, pushed pedal
real hard. Pedal was rock hard. Travel: ~ 1/2 way no sinking. Pumped
few times, checked, same
Bled brake switches**. Started engine, felt same as yesterday.
Detail: my pedal height increases slightly and stays up unless left
idle for a while.
Took to an older (German?) mechanic Wolfe, at Wetmore Motors here in
West Van. Explained work done and concerns. (pedal travel under heavy
foot pressure and pedal feel)
Before test drive, he felt pedal. His explanation (which he stuck to
after test drive) was that the caliper and rear pistons retract a
little when van sits a while. i.e. over night. Next day, first push,
fluid pushes aforementioned back out a little and more or less stay
there. This is reflected in second pedal push: pedal comes up a
little. He said that was likley what I was feeling. I asked about
pedal travel and if air in there, he said it felt normal and didn't
feel like air in system.
As a bit of an aside, one thing I'd heard, is that older (worn) rear
backing plates might flex a little under *hard* pedal pressure, thus
contributing to pedal feel. I asked him if that was an "old wives
tale" or true. He didn't really say either way, but he didn't scoff at
it either. Bear in mind, I had only a few minutes of a mechanic on a
busy day at the shop. I do notice though that at a stand still, if I
stand hard on the brakes, I hear a sound coming from rear. Almost the
same sound front pads + rotor make if pedal held at threshold and fan
creeps slightly. (normal)
Anyhow.....
He gave them the "OK". He said, in no particular order:
"feels fine". "good job" (re: my past work)
During test drive. Me: "would you drive it?" Wolfe emphatically: "yes!".
Of course I had to mention my Jetta engine install and that Westy used
to be air cooled. ;)
Absolutely the pedal does not hit the floor. Never did.
Like I said, I worry. And, sometimes what I try in earnest to explain
and ask in an email (believe it or not, I typically edit this stuff
many times before posting) may not translate to the end viewer. So, my
general query of pedal feel and/or height could have meant something
different by the time it was sent and read by others.
I guess I'm suggesting I could learn to write less, and be clearer. <grin>
Thanks again,
Neil.
** Part of a post from Dennis suggested that air could be trapped in a
brake switch(s). The term "air bound" was used. I hope I understood
this correctly. My guess is that if one bench bleeds MC properly,
bleeding switches WON'T need be done. What I did: Removed plug from
switch, placed rags under switch, (especially at rear of switch) moved
bottom of DS dash arm to left, used 24mm wrench til switch noticeably
looser, with dental mirror + good light ready, appllied and held
med-light pedal pressure, slowly finger loosened switch, watched
closely for fluid and felt when pedal moving. When pedal sunk 1/2 way
down, held it there, finger tightened as much as poss. then tightened
more with wrench. For final tightening, held end MC to make sure
wrench torque not flexing booster. I'm sure there's a torque value,
but I went by feel. I was careful not to go "Ape Tight" with it. After
all, the "bolt" of switch is a small OD. (like 10mm bolt?) Don't want
to snap it!
--
Neil Nicholson '81 VanaJetta 2.0 "Jaco"
http://tubaneil.googlepages.com/
http://groups.google.com/group/vanagons-with-vw-inline-4-cylinder-gas-engines
