Date: Thu, 17 Nov 1994 12:25:55 -0800
Sender: Vanagon Mailing List <vanagon@vanagon.com>
From: wabbott@townshend.Corp.Megatest.COM (William Abbott)
Subject: Re: Help with dragging brakes
Muir and everyone else has a good procedure for bleeding brakes,
but let me add mine.
0) WARNING: If you've just bought this bus, or its been forever
since it was bled, pumping the master cylinder from min-to-max may fray
and tear the seals in it. Its not unusual for a new old-and-freshly-
bled brake system to start showing the familiar master-cylinder drip a
week later. It sure is frustrating, because you have to do pretty much
the same thing all over again when you replace the master cylender.
I suppose you could extend the life of your existing master cylinder by
not pumping all the way to the floor, or by using a vaccuum pump to pull
fluid out of the bleeders. My philosophy is that if you have that much
crud in your master cyclinder, you need to replace it anyway, but
that just marks me as a typical liberal, throwing money at a problem.
1) build a hot-shot brake bleeding tool, using a large,
low, jar, and a couple of pieces of brass tubing from the model shop.
Buy silicone rubber tubing to match from them. Muir gives the size- you
want something that fits nicely on the bleeder nipple. Buy 1M (3 1/2') of
flexible hose and enough brass to go to the bottom of the jar, with
about 3 inches (8cm) left over.
Hot shot tool consists of two tubes fastened (Solder, epoxy,
whatever) in the lid of the jar. I prefer Marshmellow Creame jars, with
metal lids I can solder the tubes to. The most important thing about the
jar is that it doesn't tip over.
One tube mounts in the middle of the lid and goes down to
about 1/8" above the bottom of the jar. Use a scrap of cardboard, or
a wooden match, or something like that to support the end of the
tube IN THE JAR, WITH THE LID SCREWED DOWN, while you solder, glue, whatever.
(Hot glue might work with a plastic jar...) You only need about 1 inch
(2.5cm) sticking out of the top of the lid.
The other tube is about 2" (5cm) long and goes anywhere convenient
on the lid- like half-way out to the edge, with half its length in the
jar and half outside. Its the vent, and place to attach the end of the
rubber tubing when the thing isn't being used.
Mark the jar POISON BRAKE FLUID using paint, markers, etc. Brake
fluid spilled on these markings will tend to remove them, but do your best.
2) Buy a turkey baster and write POISON all over it in china
marker or something REALLY indellible. Get a heavy plastic bag to store
it in. Oh yeah, don't put any china marker or paint or whatever down on
the tip, which you are going to stick in your brake resivior.
3) Start by sucking as much old fluid out of the resivior as
you can, using the turkey baster. Put enough in the clever bleeding tool
to cover the bottom of the long tube. Put the rest in a jar you have
clearly marked POISON BRAKE FLUID.
4) Now fill the resivior with brand new brake fluid, DOT4 or DOT3.
5) Go to the wheel furthest from the resivior. That will be the
passenger side, rear, whether you're in USA, Canada, UK, Japan, etc. Remove
the little rubber cap from the bleeder nipple. If you don't have little
rubber caps, remember to go buy some from the VW place next time.
5.5) Depending on your model, agility, etc, you may or may not
want to remove the wheel for easy acess. If you do, use jack stands to support
the bus!
6) Have Friend stand by at the brake pedal.
7) Hang the appropriate, box-end, wrench around the bleeder nipple's
flats and then attach the rubber tube for the bleeder tool. Get the nipple
loosened, but don't leave it open. Have Friend push on the brake pedal,
and when they are doing so, you open the nipple with your wrench and
ugly, cruddy, old, brake fluid flows down the flexible tube and Friend's
foot goes flat on the floor. Have Friend tell you when their foot is on
the floor, and just hold it there. Close the bleeder with your wrench,
and then tell Friend to let their foot up. This sucks fresh, clean,
brake fluid from the resivior into the system, and is the ONLY way to
get the clean stuff in.
8) Repeat step 7 five more times, then, with the bleeder tightened,
go up and see how much fluid you've pumped out of the resivior. You're
going to have to keep refilling the resivior, and you don't want to run
it dry, so you have to know how many pedal pumps between top-ups. Top it
up now and go back to the wheel you're bleeding.
9) Repeat step 8 (bunch of step 7s and a refill) until you are
getting CLEAN brake fluid out at the wheel you're bleeding. With the
hot shot tool, you can see a clear layer form at the bottom when the
new fluid gets back there. That's why you use translucent tubing and
a bottle you can see through.
10) Repeat the whole business on the other rear wheel,. then
the passenger side front wheel, finaly the driver side front. Bleed each
wheel until you get clear, new-looking, fluid out of it, and, of course,
no air bubbles. Expect to use between a quart and a quart and a pint to
clear out the system if its been a while, plus whatever it takes to fill it
up.
11) Look in the Government pages of the phone book for the
household toxic waste pickup/disposal place. Brake fluid is poisonous,
and turns anything its mixed with into toxic waste that can only be incinerated
at a high temperature, at a cost of about $5-8/gallon. So if you mix it
with motor oil and leave it at motor oil recycling, all the oil it
contaminates has to be incinerated. You wouldn't want that, would you.
Yeah, this is certainly a job I let other people do for me
when I feel wealthy or run out of time. Its also a great way to get
to know your car, if you want to do that, and bond with Friend if
you're going to enjoy it!
Bill
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