Date: Fri, 31 Dec 2010 00:39:06 -0500
Reply-To: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Subject: Re: '91 Vanagon Brake Shoe Question
In-Reply-To: <20101230132512.xtzagiav404400gc@webmail.opentransfer.com>
Content-Type: text/plain; charset="iso-8859-1"
One thing about drum brakes is that rarely can they be made right just by
changing shoes. There are a number of parts that require inspection and
attention to detail is needed to assemble them and have them work correctly.
For starters, unlike disc brakes, both the shoe and drum has a radius that
needs to be matched to ensure complete contact of the shoe and friction
surface of the drum. Thus the drum has to be measured to make sure it is not
worn beyond its limit. 9.98" for the Vanagon. To make matters worse, I have
yet to see an aftermarket shoe with the proper lining thickness or material.
Most of these shoes have bonded linings of 4 or 4.5mm. The OEM shoe starts
with a riveted lining of 6mm. The OEM shoe is also metallic with a friction
rating of FG. Unfortunately these shoes are no longer available from VW.
As for spring kits many aftermarket kits have the wrong hold down
springs/pins. These are also soon to be NLA from VW.
There is an option though to help with the shoe matching. The lower shoe
rests actually consist of three pieces. The "forks" the shoes actually sit
on can be removed (torch) and shimmed out. Usually 2-3mm can be added under
each rest. This will make the bottom of the shoe contact the drum and
compensate for the VW design where the adjuster and cylinder are both on
top.
As for the cylinders, the originals had a spring that pushed the pistons out
against the shoes. ATE is the only cylinder I know that retains this feature
(usually). I have gotten some ATE that didn't. Anyway, without this spring
the pistons can get sucked back and require pushing out to contact the
shoes. This gives that need to pump symptom.
While inspecting, you need to carefully inspect the brake cables. Look
carefully at the outer jackets. Any sign of breaking, twisting, rust through
etc. means they need replacing.
Now for adjusting. The handbrake cables get adjusted before the drums go
back on and never try to adjust them afterwards. Order of adjustment is:
Assemble brakes both sides but leave brake cables off.
Adjust top adjuster to just take up slack, do not push shoes out. Be sure to
take up the slack of the adjuster lever spring or just leave it off for now.
Note how hand brake levers now swing.
Install cables on lever hooks. Adjust cable to just take up the slack where
the lever pushes on the adjuster rod. Do not tighten enough to move that
rod. Make sure both sides are even.
Install and remaining springs and the drums. Using a medium screwdriver
through hole in backing plate turn adjuster until shoes just rub drum. Hit
brakes a few times to center and adjust again. Adjusters actually work from
using the foot brake, Not the handbrake.
The shoes will need to wear into the drum to fully feel right and provide a
firm pedal.
Proper adjustment confirmed by handbrake lever needing 4 clicks to drag and
8 clicks to really set brake. Yes on Westys driver's seat does not swivel if
brake lever is up.
Hope this helps,
Dennis
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Jason Swan
Sent: Thursday, December 30, 2010 2:25 PM
To: vanagon@GERRY.VANAGON.COM
Subject: '91 Vanagon Brake Shoe Question
Hi all,
I just found the list after quite a few years with my Vanagon.
I've managed to muddle my way through most maintenance issues, but got
stumped recently. I replaced my rear brake shoes and wheel
cylinders. The cylinders were shot, and I did the shoes because I had
everything apart. Anyway, after replacing the shoes, I bled the
lines, and now I have to pump the brakes a few times before I get good
braking. In fact, the brakes act like they aren't adjusting at all.
No hand brake friction at all, and the brakes need to be pumped each
time. I did clean everything with brake cleaner and a wire brush when
I had it apart, and I'm reasonably confident that the self-adjusting
mechanism should work...
Anyway, since I don't have a ton of time, I took the van to a
recommended euro-auto mechanic who seemed to know what he was talking
about. After first telling me that it needed new brake shoes because
they were down to the metal ("funny" I said, "as the brake shoes have
less than 15 miles on them..."), then telling me I had the brake shoes
in the reverse positions (right shoe on the left, and vice versa), he
then told me that the shoes were improperly constructed because the
brake pads on both shoes are equal. He tells me there is supposed to
be a short side and a long side. If not, then the brakes won't work.
I bought the shoes at the local Advance Auto parts. I don't think
they were all that expensive. And, to be honest, after looking at the
old brakes (which both had shorter, but equal length, pads on the
shoe) I can't see how 1" less pad on the bottom of the shoe can affect
the brakes. But, this guy swore up and down that that was the
problem. I didn't have him do my brakes, as I had completely lost
confidence in him. But, before I get in there and see what else could
be the problem, I wanted to ask y'all if there is truth in this. Do I
need to go find some more brake shoes; a set with a short side and a
long side?
Thanks in advance!
--
Jason Swan
1991 Vanagon