i need to rebiuld my front master cylinder...any tips? never did this. i just ordered the kit should be here in a few days, thanks

 

kinda curious on this as well. i have to rebuild mine cause the spring has got week.

 

It's very simple. Just follow the directions in the kit. Make sure not to get dot 4 on paint. Hate that ****. The bleeding is the pita. It will take a while to get it to pump up manually with a dry master if you don't have a vacuum bleeder so be ready for some pumping. At first it will push most of the air up out of the master so just pump it gently with the cover off and watch the bubbles. Once the fluid level has gone down and the bubbles have mostly stopped you can top it off and start bleeding at the caliper.

I have never seen a spring get weak. Usually when people think it needs a rebuild its just lack of lubrication. Try lubricating where the plunger goes into the dust seal and pump the **** out of it. 9 times out of 10 that's how I fix them. It's a good idea to Lube here and the lever anytime you lube your cables.

 

It helps if you siphon off the fluid in the master cylinder reservoir so it doesn't leak or spill while you're working on it. Put a rag down below because it will drip down when you pull out the plunger. The instructions are fairly straight forward and there isn't much to mess up.

Also make sure to shim the brake lever out so as not to ruin the brake switch.

May I ask why you're rebuilding it?

 

It is pretty much plug and play, pull the old unit out, clean the bore, lube the new unit with a little brake fluid and pop it in. Once you have the new parts in your hand you will see what I mean.

Don`t forget, brake fluid is murder on painted surfaces.

 

not sure about the spring. all i know it the spring doesn't push the lever out far enough for the brake lights to stay off so the cruise kicks off and the brake lights flash from the lever vibrating just on the edge of the switch completing the circuit

 

i'm rebiulding it cause it was an aftermarket chome one that never seemed to work right, the plunger seemed to be sticky and now its just stuck in, i put the stock black one back on it works fine i'm gonna try to rebuild the chrome one i figure the cost of the kit is worth it ....if it dont work i will buy a harley chrome one

 

thanks forthe tips ...new kit should be here by wed. i know about the dot 4 and the bleeding....i just bought speed bleeders which i highly reomend..makes the process a LOT easier!

 

i watched a you tube video on this ...it looks simple hopefully it will work . i dont feel like spending 200 on an HD master right now ..been out of work for a while. if not i'll run the black one for a while, at least i can ride. oh and i know all about the deal with the brake switch too.. thanks i'll let ya know how it works out when i get the kit

 

Yep that's exactly what happens. Try some lube first. Worth a shot. Sometimes I tape or zip tie the lever down overnight and that seems to help too. Also a dirty caliper can make the lever feel spongy too. Pull the pads and clean the caliper out real good around the pistons, push the pistons back, lube the pad pins with high temp grease, put it back together and pump it up. All this can really improve the feel without rebuilding. Everything has to be clean, free and well lubed to work properly.