Bleeding rear brake caliper is not an easy task

[shurflo]

Originally Posted by mafadecay

Trouble is how do I get the air out?

put some pipe on bleed nipple and slacken right off, put end of pipe in jar and pump lever lots (keep topping up fluid as it flushes thru). Take caliper off and place it so pipe points up when you do the above, any trapped air in caliper should come out.

Once you think it is there, hold lever right in (keeping end of pipe in fluid) and nip up the nipple, pump lever a few times and voila......or maybe not in your case???:confused:

Just like you said Not in my case. These suckers just do not want to be bled. I got new fluid and tried your method (which is same as my method) still nothing. When you say pump lots how long do you mean. Ive been at it for nearly an hour now. Clear fluid no bubbles is filling the jar up.

I am really starting to get mad now. :mad:

I checked and checked the caliper for leaks and the pistons are still moving nicely. I did spy a bit of fluid on the top of the brake line and thought this was leaking but no. I must of splashed it out when pumping brakes with the cover off. I nipped it up tight just to be certain. I have traced the line all the way and no leaks. I even released the line from body and tried bleeding it as straight a I could get it. I have tried everything you have suggested. :confused:

I am using the correct procedure for bleeding (just as you all describe) but the sucker is still not working. Fluid is running through and all air bubbles go then fluid runs clear for ages but still nothing. I even tried tapping the caliper to loosen trapped air. The pistons do start to move but do not clamp the disc. I do not think the cylinder is broken as fluid spurts out. The only thing I cant do is raise the brake line and caliper higher than the resevoire as the braiding will not allow it to go that high. I have now spent 3 whole days and keep getting the same. No leaks but air still in the system somewhere.

Please, please, please help me before I cry. :( :confused: :mad:

[shurflo]

DOH....in that case I would say the master cylinder (on brake lever) is shot????

Difficult to say for deffo without seeing it???? :confused: :confused: :mad:

[660raptor]

Originally Posted by shurflo

DOH....in that case I would say the master cylinder (on brake lever) is shot????

Difficult to say for deffo without seeing it???? :confused: :confused: :mad:

With the nipple tight and the brake lever moves easily and you are sure no air I would have to agree with the above can you get a master cylinder refurb kit?

[shurflo]

Originally Posted by 660raptor

can you get a master cylinder refurb kit?

For a chinky quad???? LOL

better to get a used master and lever off a branded quad:confused:

Both sound very technical and expensive. :( It looks like the brake lever, resevoir and master cylinder are all one unit. I would have to get the exact replacement surely or would the threads be different. Any Idea what price I could expect to pay ball park.

Is the master cylinder the part that the lever pushes in with the rubber seal or the tank part on the top or are they the same thing. What can actually go wrong with them?

What is a refurb kit and how would this work and why are they specific to particular fitments?

I am still not convinced all the air is out. I think that there is still air lurking somewhere waiting to bite me on the @$$ But Im damned if I can get it out.

Here is another pic to clarify what my lever looks like. If I got branded replacement would the brake line be the same fit and if it was a good quad wouldn't the rear brake be on a pedal rather than a lever? Also would the preasure be too grate for the caliper? :confused:

took me four days to bleed my front brake on my streetfighter after changing to goodridge hoses(i know it,s not same set up as a quad but may help) i got a rubber mallet tapped all over caliper and all the way along brake lines up to master resorvoir, then slackened off brake line at resovoir pulled in brake lever tightened it back up then bled as normal loads of air as it disloges it all by using the mallet, also you know there is no air at resovoir end, if this dont help another way is to unbolt caliper put piece of wood in between pads to stop piston comming out to far and hang caliper up as far above resovoir as you can and bleed as normal. all the air will then be pushed up and out. factory,s push fluid in through the caliper bleed nipple under preasure when resorvoir full no air no bleeding but thats on assembly line so suppose they need to do it the most economical way to save time.

Lift the brake caliper has high as it will go and leave it for a couple of hours, the problem is that the hydraulic line is fairly long, it sounds like you have an air bubble part way down. once the air has worked its way to the end of the line bleeding should be straight forward.