Left Hand Rear Brake Help

[gasser]

I definitely want to make this mod to my bike. I want to retain the foot brake as well but I do not want to use the recluse LHRB set up. I have an older AJP clutch mc that I can use for the hand brake (it uses dot 4) and will retain my stock clutch mc (uses mineral oil) for the clutch. I plan on welding up a second handlebar mount as shown in these pictures: http://red450.smugmug.com/Other/Left-Hand-Brake/i-2rjfk2X
That leaves me with the part I need help with - the foot master cylinder. I've seen a video on youtube (https://www.youtube.com/watch?v=AkOzxM3yTRQ) where a fellow took out his oil sight window and welded over the hole then tapped the top (which he also welded shut)for the additional line from the hand brake mc. I would prefer to do this using a mc that has a remote reservoir (I could switch out with my son's 01 gasser). Do the older master cylinders that have a remote reservoir and no sight window have a good place to drill and tap for the second hydraulic line? I think I read somewhere that it would be better to have the second line attach somewhere low on the mc instead of at the top. Is that true? Any help would be greatly appreciated thanks - Ken

 

[gasser]

On further study it looks like it will be better to stick with my stock (2011) foot brake master cylinder and have it welded up. I'll get back with everyone with pics and details when the mods are done.

 

[jaysktms]

You could also get a longer brake line mounting bolt and put both line to the MC.

 

[gasser]

You could also get a longer brake line mounting bolt and put both line to the MC.

It's my understanding (please correct me if I'm wrong) that (without adding a second caliper to the rear wheel) the only way to have a dual activated brake is to feed the output from the hand mc into the foot mc. Since the newer master cylinders GG use for the rear brake have the reservoir built in there is only one place (unless modified) to attach the hydraulic line and that's where the hydraulic line to the rear caliper attaches. I don't think installing a double banjo bolt and attaching the line from the hand brake at that point will work. It seems to me (doing it that way) would overpressure the hand mc when using the foot brake and overpressure the foot mc when using the hand brake. Don't all hydraulic systems have to breathe so a vacuum won't keep the fluid from flowing. If so then the caps of the reservoirs would have to be vented. I believe that is one reason why the Rekulse LHRB kit replaces the cap on the foot brake mc. Their kit feeds the fluid from the hand brake into the foot brake mc by way of the replacement cap. Doing it that way routs all rear brake fluid through the rear mc and vents both hand and foot master cylinders out the cap on the hand mc.

 

[(F5)]

If you put a one way valve in the hand MC line the foot MC would work fine and the system operate as normal. Just so long as you never ever pull the hand brake.

You're welcome.

Actually I think the concept is good.

 

[jaysktms]

You are correct, I forgot the the one way.

 

[(F5)]

Um. . .

Um. . .

 

[gasgasman]

A buddy of mine has an OX-Brake on his KTM. It's cable operated. He said it works really well.