How to tell if I need to rebuild my rear brakes

[beobe99]

So, I'm in final assembly of the R and filled/ bled the brakes last night. The front's went off without a hitch, the rear is what's giving me issues.

Filled the rear Res. and started pumping the brake pedal while loosening / tightening the bleed valve as necessary. Pressure slightly built but never enough to depress the Pads. There is zero movement with the pads. I did this (pumped the brakes) for a good 10 mins. Fluid IS making it all the way through..

Do I need to rebuild the Caliper or brake "booster"?

Thanks in advance.

[Burns310r]

I assume that your pumping up the brakes, then holding the rear brake fully depresed and open/close the bleed and start over?

Just sitting there pumping them wont do anything.

Pump 3 times.
Hold the lever down,
open bleed till no more comes out.
close bleed.

Repeat...

Keep the rezzi full.

[hondaREX]

Ahhh, the good old problem with bleeding brakes. I've never had instant success with bleeding on quads. Cars and trucks I've never had the problems I have with quads.

It takes me several stages is the easiest description I can give. Pump, hold down lever, open bleeder until fluid stops flowing, close and repeat, repeat, repeat. I find keeping the reservoir cover on helps. Just pay attention to the level. I also leave the bleeder open and walk away or do something else and come back and bleed again. Again, it's just how I've had to do it in the past. When you have a good firm lever, your done!!!

To answer your question, the calipers shouldn't need a rebuild until it is leaking, damaged, or torn down for PC or paint. And the master cylinder doesn't need a rebuild unless the same as above or the lever isn't firm and fades, or looses pressure while held down.

[beobe99]

Thanks for the advice guys! I have bled many brakes in my days (cars mostly) and about 4 times on a bike/quad. The fronts gave me no issues using the same technique as mentioned (I didn't count the pumps, more of a rapid pumping till I felt pressure then release - yeah, I had a smerk on my face typing that).

Anyway I'll have another go at it tomorrow going strictly by what you guys mentioned.

Also, no leaks anywhere, why I kinda figured maybe a seal within the Master cylinder was busted.

Thanks again.

[troybilt]

I just bled my brakes. Mitivac is worth its weight in gold for the 20 bucks from Oreilly's!

[troybilt]

Are you using stainless rear line? I just had an issue where my line is leaking (brand new line :mad: ) , not allowing it to build full pressure. You can disassemble the MC with a snap ring pliers, and check the seals.

[beobe99]

Troy, It is an aftermarket braided line but I got luck and it wasn't the issue.

I followed the steps above and all is good!

I was making the mistake of basically filling the line, clearing it, and checking the pads for movement :scary:

Thanks for the mental check, I'm 99% complete with this build and naturally towards the end things have gotten tricky / complicated. Guess I'm getting antsy.