Topic: excessive travel in front brake lever solved!

[jonda500]

My CB500 project has always had play in the lever before it even touches the plunger, so I pulled off the second hand master cylinder and put the rebuilt one from my 1st CB500 on thinking this would solve it. I changed just the master cylinder. I used the same hoses and new oem lever as before - made no difference what so ever. So having ruled out the master, I next went with the easiest thing to change - the lever. Bingo!! Solved! 
I wonder if there's a rebuild kit that would work with the dud lever? (I have 2 of these brand new oem dud levers  )
John

[jonda500]

Well it seems I didn't check the part number - just trusted the ebay seller.
The 2 I bought were part number 53175-369-003, but the correct part is number 53170-369-003 dang!
Lesson learnt!
John

[bwaller]

Maybe I'm not following but is this a bleeding issue? Removing all the air will likely solve your problem. Replace the caliper bleed screw with a speedbleeder and have at it. Changing fluid is a good thing to do often.

[my name is nobody]

Or(?)..........part no. 45526-341-000   part #11 in master cyl diagram for 71 cb500.
(formerly part no. 45526-300-000)

Bushing, probably rotten and disintegrated, supposed to limit freeplay in lever.

[CBDee]

Look under the MC should be a metal plate that holds in a short rubber bushing. Remove the plate and replace bushing with short piece of vacuum hose to restore your lever play.

[jonda500]

maybe I didn't explain this properly - my picture shows 2 levers stacked on top of each other. The top lever is the one (53175-369-003) that was causing my excessive lever freeplay (over an inch at the lever end before the bit that pushes the piston in even touches it!). I know I could have removed the little metal plate and shoved something in there under it to limit the travel away from the handlebar, but I have long fingers and prefer the engagement to happen further away from the handlebar.
The bottom lever in my picture (53170-369-003) I borrowed from my other bike which didn't have excessive free play at the lever. With this correct lever fitted it makes contact with the master cylinder plunger within a few mm of movement at the end of the lever rather than over an inch of play that it had with the wrong lever fitted.

I can see two ways to get my 2 dud levers to work better - 1. Drill & tap and insert a screw to extend the bit that's too short and allow adjustability. 2. Find a TIG welder and build up the nub to match the correct part's nub.
John