HOW TO: Rebuild Your Master Cylinder

hey guys. I just followed this Howto and replaced my MS. got my parts form Chacal just like Gamuru. works greats, and was a pretty easy process!

 

Congrats on a job well done!

 

On my XJ550, which looks the same as yours, the "O-rings"/seals that go around the plunger "open up" in one direction, if you know what I mean. Do both point in the same direction or different direction? How are they oriented?

 

The Seals are positioned to Expand and apply Pressure:

I----≫≔≕≫----I The Open End placed toward the direction of travel when the Lever is pulled.

 

Gamuru- thanks, another great thread. so far my mc is in perfect shape, sans the sight glass but i'll save this for the day things change.

ron

 

Search the Forums about the Sight Glass.

You can get a Domed Wristwatch Crystal to replace the Sightglass that is a PERFECT Fit.

All you have to do is Epoxy it in place.

 

sweet, thanks Rick.

 

Great help

 

"The Old School Method"
Replacing Site Glasses with Watch Crystals
by: Rick Massey
All rights reserved.

I mixed some regular 5-Minute Epoxy. I used the narrow ends of toothpicks (many) to place the small amount of epoxy behind the crystal. [It was more like a "smear" than it was a bead.]

The outside sealing got done by placing a partial drop of epoxy at the edge. Tossing the toothpick that was used to apply the epoxy and using many other toothpicks (I had a half-dozen between my lips) to "drag along" the freshly mixed sealant taking advantage of its slow capillary action.

I used a bunch of soda cans and shot small amounts of UN-mixed epoxy on the concave bottom of the can. Then, when the epoxy you are working with just begins to "Pull" ... shitcan that mix and blend yourself one of the UN-mixed ones you have lined-up.

Once you have the sealing bead all around the new CRYSTAL ... take full advantage of it being crystal and shape the epoxy around the inside diameter of the window.

Use your little finger moistened with "Good Old-Fashioned Spit" (saliva) to make a nice looking finish ... like a glazer would do on a window.

Clean-up BOTH the Crystal AND the shape of the seal with lacquer thinner.
Use old, cotton, T-shirt cloth and moisten the cloth stretched tightly about your finger. Closer to "Damp" than "Moist"

The lacquer thinner will clean the glass off anywhere you might have goofed while simultaneously helping you apply a really fine-looking bevel on the epoxy around the glass.

If it isn't crystal or glass and you touch it with lacquer thinner; you'll be back to Square One, immediately.
- 30 -

 

rick, still got issues... rebuilt my mc. cant get a lever.... if i block off any part of the rubber hose i get lever instantly... is this turning out to be a caliper issue?

 

Certainly, smells like it.

Go "Old School"
Get a "One Man Bleeder"
Attach a "Union" and some TIGHT Rubber Windshield Washer Hose ( 2-1/2") on the Hose that slips on the Bleeder.
Yank the Bleeder.
Wrap with 3 Winds of Teflon Tape.
Puncture the Bleeder Hole if the Tape covered it.

Fill a Small Glass Jar 1/3 Up with Brake Fluid.
(Duct Tape the Jar to something that wont let the jar fall-over.

SUBMERGE the 1-Way Valve in the Jar and keep the 1-Way under Brake Fluid,
Attach the Hose to the Bleeder.
Open the Bleeder.
PUMP the Master, ... s-l-o-w-l-y.
Let the New Brake Fluid get pushed through the lines and OUT the 1-Way.

L@@K for Bubbles leaving the 1-way.
Once you have a SOLID Stream of NO AIR, ...
Close the Bleeder.

Pump 5 Times.
On 6 ...
Open the Bleeder.
Let the Fluid get PUSHED-OUT.
HOLD the Lever to the Handlebars when you do 6.
Close the Bleeder.

One of two 5 Pumps
With Bleed on 6 and Close the Bleeder...
should get all the AIR out of the System.

Dual Calipers?
Do the one furthest frpm the MC 1st.

 

Ill try it. Lol. Thanks. Only 1 caliper.. that's why I'm so flustered

 

Thanks for the How-To. Using it right now. I only wish mine looked half as good as your starting point. My dust boot on the piston disintegrated when I tried to pull it out. Had to dig the base out using a jackknife. And the e-clip is proving a bugger to get out - rusted and stuck. Of course I don't have pliers that will reach in there, soo..

 

If you have an old pair of Needle Nosed Pliers you can sacrifice, ... take them over to the Grinder with a cup of water and fabricate a Tool.

Remove a good deal of material.
fashion the JAWS with a DREMEL.

 

Thank you Rick! I was getting frustrated - every snap ring pliers I could find would not fit. So I fashioned my own - by hand mind you (no grinder). they were not as nice looking as yours, the first tips were too thin and broke. Second attempt success!

Good thing I love this bike, or I think I would have set fire to it a couple times....

 

Lol.... I wouldn't trade mine for a million dollard but sometimes I still want to set her on fire. Rick is a top notch guy. Great post and great ideas rick

 

The Circlips that come with the Rebuild Kit are even MORE difficult to remove.

The Clip is "Wider" ... and there are three "Humps" triangulated around the Inside Diameter to act as GUIDES for the Shaft Section of the Plunger.

You need to compress the NEW C-Clip until the ends touch and lift it out along the Plunger Shaft as the CUP-Return Spring shoves the whole guts out of the Cylinder.

 

Brake fluid is a great hydraulic oil but a poor rubber preservative.

There is a lubricant/preservative specifically designed for assembly of rubber seals on brake parts. Red sticky goop called Castrol Rubber Grease made from a castor oil base.

Coat seals and cylinder bore lightly upon assembly and they not only go together easier they will also last much longer.

Some of the caliper and master rebuild kits include a small sachet but if not it is readily available on ebay.

 

If that envelope you get along with Brake Parts contains "Sticky Stuff" ... It's not likely a SEAL Lubricant.
Those little Packages are more likely to contain an adhesive intended to keep the Brake Pad and Caliper Piston held-together.

"Anti-rattle" ... "Anti-squeal" Compound.

Nearly every Service Manual with a comprehensive Brake Overhaul and Maintenance Section provides the same instructions when Installing Master Cylinder, Brake Cylinder Seals and Caliper Seals.

"Use ONLY Fresh Brake Fluid from an Unopened Container"

 

The red sticky stuff in the sachet is certainly no adhesive, it wouldn't hold a fly to the ceiling. It is there to assist with the assembly, preserve the seals and to generally improve the smooth performance of the mechanism. It is exactly the same look, feel, consistency and smell as the stuff in a tub of Castrol Rubber Grease I have in the garage. (Been using it on 4WD brakes for years)

Here's the spec for the branded tub I have:

http://msdspds.castrol.com/bpglis/Fusio ... Grease.pdf

It is particularly suited for situations where you want to assemble a caliper or master that won't be used for a while. That's why brake master cylinder re-sleeve shops use it liberally on cylinders they re-sleeve and put on the shelf.

The product was originally developed by Castrol in the UK for Girling. Perhaps it isn't popular in the US, but that's what's in the sachets that came from Len.