Date: Sat, 2 Sep 2006 21:18:30 -0700
Reply-To: Joel Cort <joel_cort@YAHOO.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Joel Cort <joel_cort@YAHOO.COM>
Subject: Re: Master Brake Cylinder Install
In-Reply-To: <d338c9960609011439u617e169dh194087f90e7b5203@mail.gmail.com>
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Joel VdK
I wrote this up a few years back from my experience doing the job. It is easy and not too messy.
Let me know if I missed anything or if you need futher details.
Cheers,
another Joel with a Vanagon
joel_cort@yahoo.com
89 Syncro Westy
++++++++++++++++++++++++++++++++
To replace the brake master cylinder in a Vanagon:
Tools needed:
Phillips #2 and several flat screwdrivers
7mm wrench to loosen and tighten the brake bleeder
12 mm socket/ratchet with 9" extension (Torque wrench optional)
11 mm open end wrench for the brake line
22 mm and 24mm wrench or socket to remove or replace the
brake light switches (or one big cresent wrench)
Supplies needed:
2 pints of DOT 3 / 4 brake fluid
Rags
2 pints of rubbing alcohol
Silicone spray lubricant (optional)
brake cleaner spray (optional)
Step 0. Disconnect the battery ground terminal.
Step 1. Remove Instrument Panel:
I pulled off the cover over the instrument cluster. Then the 4 Philips
head screws. Next reach behind the Speedo cluster and squeeze the plastic
retainer holding the cable in and release that. This gives you more
play in the instrument panel to unplug the main cable cluster. To be safe you
should disconnect the battery when playing with the wiring. (see step 0) I then pull
all switches/plugs and wiring - fairly straight forward and easy. With all
that stuff out of the way the MC is sitting there with the plastic filler
tank taking up most of the space. I also disconnected the low fluid sensor
wire on the MC filler cap.
Step 2. Check for similarities with the new one:
Ok double check that the two MCs were real close in appearance. The
new one must have all the plugs and ports in the same location to route the
brake lines and the filler tank. The part in your hand may not fit your van.
Step 3. Drain the filler tank of all the brake fluid:
First you have to drain as much the brake fluid out as you can out of
the plastic container and MC. I put a hose and bottle on the bleeder on
the left front caliper and open the bleeder while pumping the brakes. This
worked well and drained all the fluid out.
Step 4. Remove the Clutch MC filler tank hose: (If you have a
manual Vanagon)
On the upper right side of the tank there is a pipe leading to a fitted
3/8" braided rubber hose going to the clutch master cylinder that needs to
be worked off. Put a rag under to collect any fluid here. I used a pair
of pliers to gently start twisting the hose and sprayed some silicone
spray lubricant. I then used several screwdrivers to pry it off and finally
my twisting motion to work it off. Be careful doing this because if it
breaks the plastic pipe you will need a new tank. Once I had the rubber hose
removed I plugged it up to prevent any brake fluid from leaking out
while I was working in there.
Step 5. Remove the brake lines:
Have a rag under both of the brake line to catch that little drip. If
you pumped the fluid out there should be minimal amounts easily captured on
a rag. Loosen the two metallic brake lines going to the front and rear
brake circuits. One brake line is on the center right side blocking the
anchoring nut so you must remove the brake line. I believe the brake line nuts
are 11mm. The other brake line is on the end of the MC and sticking out at
you. The real pain was holding a shop light in there there's no good hook.
Step 6. Loosen and remove the brake master cylinder:
Ok two brake lines off, rubber hose off, all you have left is the two
MC anchor nuts. I believe they are 12mm. They are not supper tight and
loosen out easily. I used a magnet wand to capture the loose nut and washers.
The MC is now ready to be removed. Jimmy the MC to disconnect the brake
light wiring from the two switches on the bottom and VOILA!
Step 7. Prepping the new MC for installation:
Switches
OK now you have the old one out and you can compare it to the new one.
My new MC came with the two new brake light switches but I ended up
using my old switches - 22mm wrench on my old ones 24mm on the new
ones.
The new MC switches had 3 male plugs and my old ones had 2 male at a
slightly different offset. So rather than dicker with the wiring plug
I changed the switches. Be careful to put the switches in the correct
threaded hole on the MC.
Filler tank
The plastic brake fluid tank comes out of the MC easily by prying it
out of each rubber grommets. Mine was full of 108K miles of brake line crud
so I cleaned it out. Regular rubbing alcohol works really well to break
down brake fluid. I swished alcohol around in the baffles of the filler
tank several times and it is as good as new. The new MC came with new
grommets so I just applied some silicone to ease it in. It snapped right on the
MC.
OK double check everything making sure there is a new seal between the
MC and the brake booster (which came in the box with the MC).
Step 8. New MC installation:
This is where Bentley and Haynes drop off and tell you to do it all
in reverse order.
Angle the new MC with the tank assembled and place it on the pushrod
coming out of the booster. You can press on the brake pedal to see the rod to
get a better angle at it. Ensure that the pushrod inserts into the MC
shaft. I used the same lock-ring washers and nut although two new ones were also
supplied. I used a magnetic wand to place the washers and nuts on the
threads in the tight area.
Torque it down to the right Nm from Bentley.
Refit the brake line circuits ensure that the threads are aligned and
tighten down.
Refit the braided rubber hose for the Clutch MC.
Fill with new brake fluid (I used DOT 4) and pump the brakes a few
times to get the juices flowing
Step 9 Bleeding the air out of the system.
It is absolutely imperative to get all the air out of the brake
circuit. Otherwise the brakes will be mushy and not operate efficiently.
To bleed the brakes, you need an assistant, a buddy, or one of your
kids. Kids usually whine and complain and get tired real fast. (so do wives)
OK so you want the buddy to pump on the brake pedal while you lay
under the van and open and shut the bleeders at each wheel cylinder.
Usually three action of the pedal (pump) and final pressure while you open
the bleeder works real good. You have to do all the bleeder, starting
with the furthest distance, so the right rear, then the left rear and
the right front and finally the left front. The pressure mounts after
each bleeding and repeated pumping until it is optimum.
Repeat the process once you have cycled through each bleeder. Watch
the fluid level in the plastic tank to ensure continuous level of brake
fluid and not introduce air to the circutit.
======
So at the rear wheel bleeders, loosen the bleeder. Be cautious not
to break the bleeder. Some wheel cylinders are so darn old that this is
one crusty rusty mess and the little bleeder nipple snaps. If this is
the case you will need to either get a new bleeder installed or replace
the entire wheel cylinder.
======
This is additional work to say the least that you were not planning
on. You have to remove the brake drums on the rear, the brakes the
springs to get to the wheel cylinder again consult Haynes or Bentley for
information. You may feel screewed by then, so in reference to keeping
your VW alive from the old days, go get a cold one and regroup. You are
not totally screewed but the job just became bigger. I guess you
should try to loosen the bleeders as the very first thing before starting
this job so you can guage how much of a jot it is or many more parts you
are going to need from your favorite list vendor.
===============
Some early Vans had dual front bleeders for both brake pistons.
Ensure that you bleed both pistons. I think the models after 86 came with
a single bleeder.
Step 10. Cleanup:
Hopefully you've made it through the bleeding without leaving blood,
sweat or tears. You are done. So you see this is one of the easier jobs.
If you do spill any fluid use some rubbing alcohol or brake cleaner to
clean it up and mop it up. Alcohol will work on the carpeting also to
dissolves the dripped brake fluid. If there is any on the metal
surfaces, it will eat the paint and leave bare metal ready for the rust to
attack.
Good Luck - Hope this helps
Joel
Call me if you need more help
585 377 4161
Joel VanderKwaak <joelvanderkwaak@GMAIL.COM> wrote:
Collective Wisdom:
Any warnings, tips or tricks to installing a new master brake cylinder?
Guess what I'm doing this weekend?
Thanks, and Happy Friday,
Joel
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