Brake Woes

[KitKat]

So i started disassembling the brake system and began with the master cylinder.

After cleaning the master cylinder, i reinstalled it to see if i could get my brake to function properly again. I filled up the reservoir with brake liquid, created a vacuum in the brake lines, and began pulling the lever. No bubbles rose.... i tried this for a while and nothing.

I have decided to take apart all the lines and the caliper and go through them.... but does anybody have an idea as to why nothing happened when trying to flush the lines with the cleaned master cylinder?

Thanks

 

[DanTheMan]

You have to bench bleed the master first to fill the cylinder with brake fluid.

 

[KitKat]

bench bleed? i looked on basecliff's site and was that process he used bench bleeding? if not could you explain what that is please?

Thanks

 

[Nessism]

I never bench bleed.

Suck a vacuum on one of the caliper bleed ports and fluid will be pulled out of the reservoir and prime the master cylinder. If it doesn't pump after that, something is wrong with the way you assembled the piston.

 

[KitKat]

I took off the lines and noticed that one end of the second line (from the split to the caliper) was clogged. After removing the clog with wire and compressed air, i checked that all the lines were free and the nipple and the entrance to the banjo bolt in the caliper were also clear (using compressed air). I reassembled the lines and poured liquid into the reservoir. I created a vacuum by connecting a pipe to the caliper nipple (after unscrewing it a bit) and placing the end of that pipe in a bottle of water.

I pumped the lever and big bubbles started to rise in the reservoir , however, after a little bit, the big bubbles ceased and white - hazy ish stuff with smaller bubbles took its place. I noticed too that the fluid level wasn't really decreasing so i called it a night.

Any suggestions as for what to do next?

Thanks

 

[almarconi]

In order to clean the MC you have to take it apart. Once apart, clean all the components in clean brake fluid. Inspect the bore of the MC for pitting, rust..etc. If the bore has a lot of pits you are better off replacing the MC. If the MC bore is acceptable, I would purchase a rebuild kit for the MC which will include a new piston and spring. If your bike has a removable reservoir, remove it and the seal. Clean this area as well as the return hole. This is best cleaned with a single wire strand from a wire brush.

If your lines are clogged, they should be replaced. Braided SS would be your best choice. There is an excellent thread on here by Nessism on how to make brake lines. If your not comfortable making your own, Z1 sells goodridge lines and fitting that are easy to install. The calipers should also be taken apart, cleaned, inspected, and reassembled. If the caliper pistons are in good shape, just get some new seals. Replace all the crush washers with new ones and clean all the banjo bolts. Use fresh DOT 3 or DOT 4 brake fluid.

Bleeding the brakes is not that difficult. Get yourself a vacuum brake bleeder. Harbor freight sells them if your budget is tight. You can bleed the brakes the old fashion way but the vacuum bleeder is much easier.

Proper braking function is not an option. YOUR LIFE DEPENDS ON THEM WORKING. Don't take short cuts because you can't wait to ride the bike or your trying to save a couple bucks. Spend the time to fix them correctly.
If you are unsure about something just ask.