Date: Sun, 19 May 1996 21:24:14 -0500
Sender: Vanagon Mailing List <vanagon@vanagon.com>
From: walshp@h1l6xa.nawc-ad-indy.navy.mil (Pat Walsh)
Subject: Report: Replacing brake lines, MC & booster in '71
I've been doing some work underneath the bus recently and thought I'd take
the time to post my results.
Over the winter, I'd adjusted the spring plates to remove the sag from the
Westy's rear end. In doing so, I noticed that some of the 25 year old
brake lines looked kind of rusted or corroded. I was surprised to see
that not only did Wolfsburg West have all the lines for the bus, but they
had a kit containing all the pieces for only $41. I ordered a set and
also 10 of the rubber grommets that go around the lines. These were over
$1 each. The kit includes all the metal lines. The front rubber hoses
had already been replaced and the back ones seemed okay. NOPI had master
cylinders for $25 new so I went ahead and got one, too.
Everything arrived and I started putting it all together. The first thing
was swapping out the MC. The old MC didn't form a good seal with the
booster and allowed air to leak. As a result, the booster was
disconnected since I bought the bus. When I took the old MC off, I
discovered that it was shimmed with some washers away from the booster,
thus explaining the leak. I bolted the new MC to the booster and noticed
that the pushrod bottomed out when the MC still had about 1/8"-1/4" to go
before contacting the booster. I figured this was incorrect and the wrong
booster was installed, but I didn't really know how to tell for sure so I
went ahead and bolted it up. Before I went any further, though, I checked
the booster by hooking the large vacuum hose up and blowing in. The
air went straight through to the other side, telling me the diaphragm was
bad. I called a mechanic I've dealt with before, who has a junkyard out
back. He said he'd want $50 for a used unit but he'd need to see if he
could find one. He's out of town and after calling him back several times
to see if he'd pulled one from a junker yet, I gave up and ordered a
rebuilt one. Both RMMW and Wolfsburg West had them for $180, more than I
wanted to spend but finally getting the power brakes working is one of
the last things on my list before considering my bus project more or less
"complete" (yeah, right! I'll still be working on it years from now.) so
I ordered one from WW.
While waiting for it to arrive, I started replacing the lines. Not really
a hard job, just kind of time consuming. Except for one long one, the
lines come straight with each end flared and the fittings installed.
Seemed to be pretty high quality. I'd got a loaner tubing bender but
ended up just bending it mostly by hand. You have to measure the old
lines as you replace them, so you select the right length piece of tubing
from the kit. The tubing was fairly sturdy and I didn't run into any
problem with kinks. Got the pieces pretty close by using the old tubing
as a guide, but of course there were some minor adjustments needed as I
hooked up each one.
When the rebuilt booster arrived, it was a bit smaller in diameter than
the old one, and sure enough the pushrod didn't bottom out when the two
were bolted together. Did the air test with the hose and no leaks. Oh,
forgot to mention about switching the lower brake fluid reservoir from the
old MC to the new one. The bottom of the plastic reservoir has two nipples
extending down from it. They go into two large rubber grommets, which
then fit into the master cylinder. I'd ordered new grommets, but had
read on the list that the reservoirs are no longer available so I knew I
had to be careful. The two are REAL hard to separate! Tried various
prying techniques but it looked like I'd mangle up the reservoir before it
came off if I went that route. Finally tried lashing the MC to a post in
the garage using a couple of turns of baling wire. Braced my feet against
the post and grabbed the reservoir with both hands and pulled it straight
away from the MC. It worked good and came out undamaged. So anyway, I
bolted in the booster and MC, hooked the lines to the MC, connected up
the wires to the switches and adjusted the rod between the pedal and the
booster. I'd bought the correct type and size rubber hose for the booster
a long time back, and finally hooked THAT up. Did the test of sucking on
the hose and putting my tongue over the end and it still held with
everything in place and hooked up. One of the few things the PO had done
that made sense was hanging onto the little one way valve, which I'd found
a long time ago in the glove compartment.
Next, it was time to fill the system with fluid and bleed the brakes. I'd
bought one of the hand pumps from JC Whitney a while back and I'd have to
give this technique only mixed reviews. The pump would seem to create a
vacuum okay, but sometimes the fluid didn't really want to come out the
open bleeder. I think I had to go up to the front at least once on each
wheel and give the pedal a few pumps to speed things up and get the fluid
moving.
Double checked everything and now it was time to test it out. Started
the engine up and the first sign something was wrong was the brake light
on the dash stayed on when there was no pressure on the pedal, but went
off when I pressed on the brakes. I thought (hoped) it was only that I'd
hooked the wires up wrong and not a problem with the system. The other
bad thing was that the engine would start to die when I pressed down on
the pedal. That sounded like some problem inside the booster and I wasn't
looking forward to dismounting it and trying to get Wolfsburg West to
exchange it, then putting on the new one and bleeding the system all over
again. But the one GOOD thing was that after I shut off the engine, I
pressed the pedal very firmly several times and didn't find ANY leaks
when I looked underneath. That was a pleasant surprise, considering how
many connections I'd had the potential to not get tight enough!
Called it a day and went inside and studied the diagram of how the brake
switches work. The next morning I went out and checked the wires and sure
enough, two were switched. Checked everything else again. Tried bleeding
the brakes some more, just in case, but no more bubbles came out. Still
no signs of leaks. Turned the key on and this time the brake light on the
dash didn't come on, and stayed off when I pushed down on the pedal. The
brake lights in back worked normally. So I started it up, and this time
I noticed the bus was in gear! All this time, the bus has been on jack
stands at each corner, and the back wheels were off, so I hadn't payed too
much attention to whether it was in gear or not. I HAD noticed the back
drums rotating slowly when I'd run it the other day, but they do that when
they're off the ground even when it's NOT in gear. But this time when I
started it, I did the brake testing with the transmission in neutral and
no more problems with it starting to bog/die when the brakes were
activated! Yay!
Well, that was last weekend and things seem to be okay. Have to say that
I didn't see THAT big a difference between power and non-power brakes.
There's less pedal effort but it's not like it was super hard to work them
before. But still, with a new MC, booster and lines, plus shoes, calipers
and pads not too far back, it's nice to know that I shouldn't have to
worry about brakes for awhile. Plus, I feel I've got a pretty good
understanding now of how the system all works. Anyway, just thought I'd
share a story with a good ending. One thing that's kind of funny is that
I still couldn't believe that there weren't ANY leaks and ended up
imagining that the fluid in the reservoir was just a little less than what
it had been. Finally had to put a little mark on the side where the level
was and after driving it for a couple of days with NO change, I guess I
have to admit it's really NOT leaking! :-)
Pat Walsh, '71 Westy, walshp@camry.nawc-ad-indy.navy.mil
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