Need rebuild tutorial for 96 R1100RS front brake master cylinder

[bubbadozer1]

Ok, found a great tutorial. Now I just need to know where I can get s rebuild kit/parts to overhaul master cylinder. A new master cylinder is over $500��. So, would appreciate being pointed in the direction where I can get s kit.

Cheers

 

[etinch]

Start with a rebuild kit from Beemerboneyard and these instructions:

http://www.largiader.com/tech/r11mc/

I found a 3/4" brake hone on Amazon for just a few bucks. I had to do mine twice. The first time I just tried sanding by hand and it stopped leaking but still was a little sticky, the hone really made a difference the 2nd time. Also bought some brake assembly lube as recommended by someone here the 2nd time and I'm sure that helped.

 

[179212]

Rebuilt master cylinder

I got a 1994 1100RS that had set for a lot of years had 27,000 miles on it front master cylinder rebuilt took bike home rode it some drip of brake fluid on faring same places as before so no new damage dealer put new one one. Got bike 8/3/10 so 7 years 50,000 more miles no problems, so might want to take big gulp swallow and buy the new one. If the brake lines old rubber ones take a bigger bite and replace them also.
Just reread your post new master cylinder $500 seven years ago seems like they cost $330 or so plus having to remove grips and heating thing makes rebuilding look better so from my experience and what etinch said it may not work the first time , but $500 in parts a few hours labor at dealer and your in the $1000 ballpark. ( glad mine has not leaked again )

 

[rxcrider]

Wilwood Brake Assembly Lube is what I used and recommended, but it is showing unavailable every place I look at the moment. Wilwood lists a phone number to order it, as does Jegs.

 

[bubbadozer1]

Brake bleeding and overhaul of my 96 R1100RS front master cylinder question

I have ordered a rebuild kit or my front brake master cylinder on my R1100RS(L) from Beemer Boneyard, and just bought a brake bleeder and vaccuum pump it. I have always done my brakes the old fashion way, but broke down and thought I would finally get the tool to do it easier. I was wondering if there is anything special I need to know since the bike has ABS, like is it a different process than non ABS bikes.

My MC is leaking at the piston shaft passed the rubber boot. Almost messed up my plastics. If anyone has any words of wisdom for this BMW newbie, I will forever be in your debt. I have been asking so many questions on here, I'm afraid other members are getting sick of me. I really wish I had someone nearby me I could learn from

Cheers

 

[Omega Man]

You have been receiving some answers from you original post. Looks like the same subject so I will combine them for you.
Good luck.
Gary

 

[bubbadozer1]

Omega Man, Thanks so much. Sorry about that.. I appreciate the patience. I'm afraid my computer skills are worse than my BMW knowledge.

Cheers

 

[Omega Man]

Your doin' fine

 

[bubbadozer1]

Start with a rebuild kit from Beemerboneyard and these instructions:

http://www.largiader.com/tech/r11mc/

I found a 3/4" brake hone on Amazon for just a few bucks. I had to do mine twice. The first time I just tried sanding by hand and it stopped leaking but still was a little sticky, the hone really made a difference the 2nd time. Also bought some brake assembly lube as recommended by someone here the 2nd time and I'm sure that helped.

Thx much for the heads up on Beemer Boneyard. I picked up a brand that was surd by BMW, and they only have so many left, and picked one up for half of what BMW wants for a rebuild kit.

 

[jagarra]

Since i just did the annual brake flush on my 94 RS here is the process you may try. To remove the fluid from the reservoir I remove the tank and go to the ABS unit, the bleed nipple on the right side is for the front brakes, left for the rear. Hook your vacuum pump to the right nipple through the catch container, making sure the hoses are hooked up as per instructions on top of lid. Pump it until you have 15 or 20 inches of vacuum and open the bleed nipple, this will suck the fluid out of the reservoir. the nipples on the BMW are 11mm so I use a box wrench. This should clear the fluid between the MC and the ABS so the master can be removed. I usually cover the side of the bike with a plastic garbage bag to protect plastic.
After master is rebuilt, fill the unit without the rubber piece ( I place cover on top) and go back to the abs unit, repeat pumping up vacuum and open valve to pull fluid into catch unit. Just do this once and then check fluid level, you don't want to run it dry, repeat a couple times till you don't see any big bubbles. Now you have to go to the calipers, do the same starting with the left caliper and then the right till you don't see any big bubbles, hopefully you should start feeling brake from the handle. CAUTION!!! never pull lever with the MC cap off, when you release lever it shoots a stream of fluid all over the place!!
Before you button up the MC do not over fill it as when the rubber piece is placed in there it will cause it to overflow.
After I finish bleeding and everything is buttoned up I pump the brakes up with the brake lever and strap it the handlebar with a bungee cord so pressure is on the system, I leave this overnight and in the morning the lever is way up there and solid.

 

[bubbadozer1]

Jaggara,

Thanks for the reply. Do I need to take tank off and do this from ABS unit, or can it all be done from calipers? Sounds like no, but I wasn't sure. I have to rebuild MC, and from what I read from another post, it can be done from on the bike. I was hoping I could conduct the refill/flush from calipers, but from what your saying, that's not the case.

Thanks again for the response.

 

[etinch]

Wilwood Brake Assembly Lube is what I used and recommended, but it is showing unavailable every place I look at the moment. Wilwood lists a phone number to order it, as does Jegs.

Yep, that's the stuff, thanks again. I'll be using it anytime I have a caliper apart.

And thanks again to Mr. Largiader, what a great resource his site is.

Bubbudozer, how is the rebuild going? One thing I forgot to mention is to clean and lube the pivot pin very well. This is another thing I didn't do well the first time, but on advice of people here did the 2nd time and I'm sure it contributed to the easy lever return action. This first time I just wiped it off and applied a little lube, but the 2nd time I noticed (or someone here told me, I'm not sure..) that there is a actually a sleeve that needs removed to clean it well. It was so dirty it looked like the sleeve was part of the pin. And a guitar string comes in handy when cleaning out the small return hole in the floor of the MC.

Regarding bleeding at the ABS unit: I'm sure this is the way to get 100% of the fluid out, but I almost always skip it and probably get 98% of the fluid just through the calipers. I believe as long as you activate the ABS a few times every year then you should get all the fluid at least every 2nd flush. I only take my tank off when I really need to because it's such a pain to get back on. The tank seems to swell over the years and I have almost pushed it off the centerstand a couple times trying to get the bolt to line up. This isn't an option on bikes with booster brakes ('02~04?) as they must be bled at the ABS unit, but has always worked well on my '94.

The last thing I'll mention is to consider some new brake lines, I used Spieglers on mine. New lines, pads, master cylinder rebuild and two years later the lever still feels and returns like a new bike. Let us know how it turns out.

 

[pglaves]

If you are the patient type you can bleed/change fluid in the front circuit of the R1100RS using gravity alone. Attach a hose and open the bleed valve at a wheel caliper. Add fluid at the top as it drains out the bottom. When it runs clear close that valve - repeat for a very short time at the second caliper. Top off the level in the reservoir and put the cover back on.

I did it last week at a National Forest campground.

 

[rxcrider]

If you are the patient type you can bleed/change fluid in the front circuit of the R1100RS using gravity alone. Attach a hose and open the bleed valve at a wheel caliper. Add fluid at the top as it drains out the bottom. When it runs clear close that valve - repeat for a very short time at the second caliper. Top off the level in the reservoir and put the cover back on.

I did it last week at a National Forest campground.

...but not if you've introduced air to the the system and gotten it into the ABS unit. To pull this off on a MC rebuild would require keeping fluid in the line, nearly to the MC. Then, after the rebuild, you'd need to reverse bleed the system from the calipers to get the air completely out of the upper line and MC. You'd need to be very careful to avoid allowing any air in at the calipers. Once you were sure all the air was purged, you could flush / bleed with fresh fluid from the top down. If it were me, I'd just pull the tank and bleed it at the ABS box. I'd also be installing a set of braided stainless lines if they aren't already on there.

Side note: To prevent a squirt of fluid from exiting the MC reservoir, bend up a little baffle out of some clean sheet metal and put it over the ports in the bottom of the reservoir. It basically ends up looking like a tiny u channel which allows the fluid to flow freely under it, but blocks the fluid from squirting out. Be sure to remove it when you are done beleeding.