Rear brake bleeding - works for a little bit then doesn't

[Guest]

So I have been bleeding the rear brake, getting brake fluid everywhere.

Twice has I been able to get the brakes to sort of work, but then I ride for a bit, and nothing.

Any ideas as to what I can be doing wrong?

I bleed the two nipples on the caliper itself, I don't think you bleed the master cylinder on the rear. I did not torque the bleed nipples very hard, and the lid for the reservoir was somewhat loseish (apparently before the lid is torqued the whole reservoir starts spinning?). I torqued the bolts on the caliper itself after hand feel.

I thought tomorrow Ill buy a vacuum one to fix this. I have the lines with the flowback valves but they are useless. They fill up with brake fluid and then pooof off and shoot brake fluid everywhere.

The brake at the last attempt was able to hold the bike from rolling out of my driveway, but fairly quickly just stopped working.

But the rear brake is no longer dragging, so that is an improvement.

Why is the lid to the reservoir so hard to get off? It seems like a dumb placement for it.

 

[Guest]

Do you have the circular reservoir that is held in place by a round clip? If that clip is loose, tighten it, or if you can't tighten it any more, wedge a thin piece of plastic or something between the clip and the reservoir. It shouldn't move at all.

Regarding the one-way valves, do you have them fitted the right way round? There is probably an arrow on the valve somewhere to help.

 

[Guest]

Do you have the circular reservoir that is held in place by a round clip? If that clip is loose, tighten it, or if you can't tighten it any more, wedge a thin piece of plastic or something between the clip and the reservoir. It shouldn't move at all.

Regarding the one-way valves, do you have them fitted the right way round? There is probably an arrow on the valve somewhere to help.

I do have the round one. I will try to tighten the screw.

There is only one way they could be fitted. One end has the flowback valve and the other has a nipple for a rubber connector that connects to the caliper bleeder.

 

[Grimly]

Get a large plastic syringe from your local agri-parts supplier, put a piece of aquarium air tubing on the end and the other end on the nipple.
First of all, wrap a couple of turns of teflon tape around the threads of the nipple and screw it in, then just slacken off enough to let some fluid come out when you pull a vacuum with the syringe.
On a caliper with two nipples, bleed the furthest away one first.

Never fails and cost a couple of buck / euros.