Master Cyl rebuild

[RanMan]

Hi All,

I have read the guide for rebuilding a master cylinder and still have some questions.

My 1980 XS1100SG front M/C does not have a plate holding the reservoir in place. I have tried to carefully work it off for cleaning underneath but am concerned about using too much force. I can get it to rotate and separate slightly but it will not "pop" off.

Careful prying has not yielded much results. Is there a way to remove the plastic reservoir or am I risking damage? I'd like to refinish the metal body, replace the o-ring seal and apply some Yamabond to eliminate seepage.

Also, are there any other methods recommended for cleaning up the bore beside what the sticky suggests? Mine is in very good condition with only a small amount of graying where the outer rubber cup rides.

One more question; should I use semi gloss paint or are there better options?

Thanks guy and ride on brothers.

[cajun31]

Ranman

you have to just continue using even force on both sides. There is a large O ring that fits around the bottom of the reservoir plastic. It snaps into place in a groove within the metal bottom. Depending on the condition of the plastic should dictate the amount of force you want to use. As for cleaning the best thing to use to clean the bore etc. is a good carb cleaning solution. Just make sure you get it all out before reassembly. I used a semi gloss black to paint mine before reassembly. It holds up ok, but I wish I would have had it powder coated. That as well as the calipers. Plan to do that in the future. I believe the powder coat will hold up longer against brake fluid spills, seepage, etc... By the way, you shouldn't have to use any yamabond if you get everything cleaned good and replace that large O ring. Make sure you get the spooge hole cleaned good and that there is no blockage. I used a small strong flashlight to shine in mine to make sure it was clean and clear. If you don't pay attention to that you will never get the brakes to keep from sticking binding.

[RanMan]

Cajun 31

Thanks Cajun,

That makes sense. Good suggestion on the powder coating too. Fortunately, my Yam has been kept indoors most of it's life so corrosion is minimal. I think I'll be OK without "honing" the bore. With aluminum, that's a risky move. I may pursue the reservoir removal using wooden wedges (clothespins- haha) but we all know 37 y.o. plastic can be brittle. All passages are clear too but there was some crud at the bottom which I carefully brushed away with brake clean. Carb cleaner is another good idea.

I've been going over the bike and repairing some light front end damage from my first collision in 47 years of riding. "I didn't see you" she said.... (No sh*t, lady). Surprising how much damage can be done broadsiding an SUV at 15 mph... I'm just happy the forks survived.

I really lucked out finding NOS parts too at the right time on eBay.

Thanks again

[Schming]

Jat

You may want to use caliper paint on your MC, I'm not positive but it may be less likely to be affected by brake fluid.

For the bore of the MC I suggest using a dremel buff with some aluminum polish and shine her up then clean all residue with dawn dish soap before assembly.
Assemble piston with a light coating of brake fluid and reservior with a smear of Sil-glyde grease on the o-ring and you're good to go.

[RanMan]

Schming

Ahh, yes! A Dremel buff would be just right. Great idea and I just bought a Dremel accessory kit soooo

Anyone know the correct size for the reservoir O-ring?

Thanks!

[cajun31]

Caliper paint

That is what I used on my calipers by last go through. It does hold up slightly better then normal paint, however I do think that powder coating would hold up better. I wish I could help you with the O ring size but there is no info that I can find on them. You may find when you get is disassembled that you can re use the one you have with the application of the grease as Schming suggested. Sorry to here of your fender bender. I had a jerk pull out in front of me in October and I had to lay my Harley down to avoid more serious problems. Banged me and the bike up but we survived to complain about it. Of course the jerk stopped and said I didn't see you etc.... Good luck on your rebuild. Didn't see that you mentioned it anywhere but if you are going through the front master, if I were you I would continue and do the entire system front and back. Don't know what your budget is but this is a thread I started when I did mine and there is a lot of good information and sources for things you might need to acquire and do in order to do the job properly http://www.xs11.com/forum/showthread.php?t=41610.

[RanMan]

Cajun

You guys have all given good advice and options and it's really nice to know we have such a great group of XS people.

Sorry to hear about your lay down event. Mine was also back in October on the 14th. It was such a beautiful day too... then there was the pea gravel that some truck spread by speeding around the corner. There's no doubt in my mind that I could have stopped before broadsiding the woman if it weren't for the gravel.

I'm actually working on the front brake system now. The calipers are finished and the MC will be soon. Then, like you suggested, I'll be tackling the rear brakes in entirety. Even with regular fluid changes, there was still a small buildup of sludge in both the front calipers and MC.

I'll likely go with caliper paint for now unless my buddy's son's race car shop is doing powder coating now. We'll see.

Thanks again!

[RanMan]

MC continued

So, I used a 1/2" wooden dowel and a piece of generic washcloth, soaked in chrome/metal polish to clean up the bore. About 10-15 seconds worth of polishing has yielded a satisfactory finish, IMO. Only because the bore was in such good condition did I choose to try this first.

I found the red rubber grease on eBay for about $10 for 2 oz. (one US seller in NJ) and they sent me the wrong stuff (moly grease) so I wait a few more days to complete this.

Hope this helps add some options to the task. I'll post images later today.

Thanks, All