I want to upgrade the levers on my bike. The clutch side is straight forward. But I'm unsure about the brake side. My concern is with the brake master clinder piston and spring on which the lever pushes. Is the spring under some preload and do I have to somehow hold the piston when I remove the lever? If so, then what is the best way to hold that piston?

The service manual cautions me not to remove the master cylinder without adding a thick cardboard insert between the brake lever and lever bracket, otherwise damage could occur to the rubber boot and plunger of the front stoplight switch. But it is unclear whether the cardboard is needed or whether the plunger/piston needs to be held when the lever is removed.

I hope this all makes sense.

 

Just remove and replace, very strait forward.

 

Dave,

Then what is the precaution for? I don't want to take the switch housing part to find the hard way how the lever and stoplight switch work. But the cardboard shim puzzles me. The manual is vague on the switch and plunger action.

Thanks.

 

Honestly, the first one I ever changed, I just did it. Nothing came springing out at me. I just removed the lever and put the new one on. Let me finish eating and i'll go take mine off and see if there is really anything to worry about.

 

The card board shim is just so you don't bum up the little button on the brake light switch. Don't sweat it. Just stick a piece of cardboard in and swap the levers. It takes less than 2 minutes to do. The hardest part if fighting the snap ring on the pin.

 

You mean of course that wonderful little sanp ring that goes snap and across the garage, never to be seen again. And then when I look into my tool box, I find I don't have anymore of them, that little ring! Good thing they are cheepo at Home Depot!

As soon as my new levers arrive, I'll be all set. Thanks for the help.

 

Alright, sounds like you got it licked. Apparently the cardboard is there to keep you from damaging the rubber boot on the brake light switch. If you want to go that route I can't see any issue with doing it that way. When you get the lever off I think you will see what I mean. I guess if you muscle fokked it around you could damage the boot but there is really no need to get aggressive with it. It slides in pretty easilly. If I remember right, you put the part of the lever that contacts the switch in first and then just rotate it into place to line up the hole for the pin and then install that snap ring you love so much. LOL
The only issue I ever had with changing the levers was when I bought some at Bike Week in Myrtle Beach a few years ago and intalled them in the hotel parking lot. They were aftermarket levers and one of them was a little too wide to fit into the housing. I walked over to the curb and used the curb as a serious low buck grinder. Worked perfect! LOL