Master Cylinder Sleeve

[kp]

Just received back a spare no line master cylinder after installation of a 9/16" stainless sleeve. This master cylinder had a corroded inner and wouldn't have been worth anything unless fixed. Cost was $135 (Ozzie $) ]and given the rarity of these correctly coded no line Master Cylinders, worth every penny. Also a photo of another no line and early correct coded Kawasaki, anodise stripped, MCs ready for polishing and re-anodising.
I understand these can be re-bored to 5/8" and will work fine but I couldn't find anyone to do that job. (I didn't look that hard though)

[Sam]

Ive heard of this being done to expired master cylinders. What was the original inner diameter? Was is 9/16ths?

[kp]

Yes, the original is 9/16". They bore them out  and re-sleeve (press in) with a 9/16" bore stainless tube. I've heard some say one can bore them out to 5/8" and not sleeve them but I have no knowledge of this other than to say 5/8" is a dual disc MC for a Kawasaki (and maybe Honda dual disc as well) Both manufacturers use the same company to make their MC's
I prefer stainless cos it'll never give a problem again especially for a motorcycle that is basically going to sit and I now use only DOT 5 fluids.
I'm sick of rebuilding my brake components. I have a garage queen CBX and it's forever requiring brake servicing. My road riding CBX also has the same problem. Fluids become water contaminated over time
My good restorer friend doesn't actually fill the reservoirs keeping them lubed and left. A good idea for bikes never ridden I spose. 

[hondasan]

I started using DOT 5 silicon fluid about 30 years ago after a CBX master cylinder leaked onto its fuel tank and stripped the paint. The reason for using it at the time was primarily to avoid further paint work mishaps as silicon is safe against paintwork. The added benefit is that it does not absorb moisture hence solves the problem of corrosion of brake system components. ALL of my Honda's have this fluid in them now.
My rider sandcast was re-built for the second time a couple of years ago, just over 100,000 miles / 25 years after the first rebuild. DOT 5 silicon had been in it for all those miles / years and the brake system was spotless inside.
I have been told that silicon fluids are not recommended for more modern vehicles with ABS systems - not something I wish to comment on!

Just my experiences - Chris R.