Bonneville America Forums Forums Technical Forums Custom Corner Rear brake master cylinder?

Hi, can you suggest a rear brake master cylinder for retro fit to our bikes? I am relocating the foot controls further forward and want a single unit so I can remove the remote rear reservoir. I want a classic look, preferably not chrome, and must be compatible with current caliper which means Dot 4. I like the Wagner lockheed style but they are Dot 5 only.....

These are the foot controls I'm starting with:

maybe you can find what you want in here
http://www.rizoma.com/default.cfm

I can't believe there's any legitimate reason that dot 4 or 5 would render any unit unacceptable!???

theres always a legal reason

I really didn't want to start mix matching components when it comes to brakes

Dot 4 is Glycol based and Dot 5 is silicone based.

I have read that dot 4 fluid will eat the seals in dot 5 components, and vice versa I don't know if dot 5 fluid would work in our calipers

Well, there ya go. And I thought all seals were rubber.

(Sure hope thats not a problem with DOT1, 2, and 3, as I've mixed them in the past.)

P.S., I wonder if the seals get damaged by a MIXTURE OF Glycol & Silicon, like radiator coolant, and not by using one in lue of the other?

You cant mix DOT 3/4 with DOT 5. The mixture will turn into a jell type solution.....Angelis

This is a VERY valuable thing to learn!
Thank you VERY much.

If you want to read about it:
http://www.motorcycleproject.com/motorcycle/text/cows-brakefluid.html

Good read.

Remember you can always move your stock master cylinder and relocate your stock resevoir up higher or in a location that is out of the way. You can also use a different resevoir if you want,chrome,black,etc.. You can use a longer hose/tube set up.

I think I've settled on an older model Harley sportster (aftermarket) rear cylinder because it is 5/8 cylinder that uses dot 4 fluid. Just got to find the best one on ebay now....also need the plunger rod....

As with all the other projects, this one is going slow but I made some progress yesterday. The forward control mounts were cut and tacked together and I'm happy with the position. They are approx 65mm further forward (guess) and 65mm slimmer from end to end than standard. Feels great to sit on as it fits my 6'3" body much better.






I can't wait to get these projects finished now!!!!

Lookin good. I like the way its progressing.
Thanks for the pics.

Dropped off at the welders today, should be done by the end of the week. So now I can work on a couple of other small projects like indicators and handlebars before getting it all back Friday when I'll have to grind all the welds and start assembly!!!