I've had problems bleeding a back brake. I finally got good results using a pressurised bleed system that I got from Halfords. Can't remember who makes it - I think it's called an eezibleed - but essentially, its a tough polythene bottle with two tubes coming out of it. One tube comes right down from the bottom of the bottle, through the bottle cap and finishes a couple of feet later in a screw cap that fits in place of your master cylinder cap. The other tube has a valve on the end just like a foot pump, that you clip onto a tyre valve. That tube pressurises the polythene bottle. So you hook it all up dry, clip the air valve on to your front or rear tyre and make sure there are no leaks. When you're sure that there are no leaks, you fill the bottle with brake fluid and clip the air supply back on. Now, the bottle is pressurised and the fluid is forced through under pressure, so all you need to do is open the bleed nipple until the fluid runs clear. It's a great way of forcing airlocks out, but if you end up using one make sure you have no leaks - brake fluid fountains are no fun. I know this is stating the obvious, but I once spent a few hours trying to bleed a front brake with exactly the same symptoms as you describe - then remembered that I had left the diaphragm in the master cylinder reservoir [Edited on 25-3-2004 by Jools] |