So I have yet another question that confirms my noobness . My 04 Rev 3 developed a hole in the rear brake line from rubbing on the chain (I know, i really should have caught that). I got a replacement, and installed it but could not get it to bleed at all. The consensus was that with these brakes it is better to reverse bleed. I got a syringe, and attached it to the nipple with hose, opened the valve pressed and nothing. I can't get any of it to go into the line, What is the most likely place i went wrong? I have bled brakes before, and while I am a ham fist, I have never had this kind of issue. suggestions? I am finally getting to where i want to use my rear brake to turn and am learning to hop a bit, and i REALLY need to work on off camber downhill turns (which are kind of sketchy front brake only).
Works best if you have a friend to help... Have them put the pressure on the line and then crack each fitting tell you get a little fluid out, then move to the next starting with the one at the caliper, then the one at the pump, then you should get enough pressure to push past the bubble and get the flow your looking for. I found on one of my bikes that I ended up needing to do a top down pressure cycle to get enough air out of the system for a good reverse flow... Hope this helps.
I'd pull the bleed nipple and try pushing through it to see if it's plugged, if not I would reinstall and move down the line until I found where it is plugged.
A bleeder must be opened up to pass fluid in reverse. The tapered ends of the typical bleeders suck for mounting hoses, and the fitting is loose when open so it will leak. To pressure bleed you need something that goes in snug and holds the bleeder hose on securely. I use mountain bike brake line fittings that are barb ended and have the same M6X1.0 thread as the AJP brake bleeders. Maybe the fittings I have are rare? I'll try to remember to measure the specific thread for AJP bleeders. Maybe something in here might work? http://www.jensonusa.com/Hydraulic-Brake-Lines-and-Fittings
http://www.lewisportusa.com/manuals...o_brake_and_clutch_system_bleeding_manual.pdf Here is an approach at bleeding. I use the gravity method, but use a 3 foot hose straight up. You have to bleed out the banjo bolts first to get the fluid moving.
We should be down by 10 or so, but I'll probably have to put it off till after fiesta, but the case offer stands
The specific AJP bleeder thread is the common M6 X 1.0 (standard metric coarse) and the barb end of the mountain bike fitting is for 4mm hose. A person could make a pressure bleeding fitting from a 6mm fastener if need be by drilling a hole through the center a pushing hose on. If you lack a lathe, putting the fastener in a drill and turning slowly against the side of a bench grinder wheel works as a lather substitute to finish the outsides of things well.
To get a tight seal I use surgical tubing. Most hard wear stores have it but some hide it and you have to ask for it. Guess to keep the druggies away. Any way, then I use thin safety wire, but any will do. Wrap it and give it a good twist. Be patient as it can take a while for it to get moving. Assuming the nipple isn't plugged.
Have you taken the cover off the top master cylinder, have you opened the bleed nipple while trying to squeeze fluid through line and remember to close it while you are refilling the syringe. I find it easier also if the lever adjustment is backed all the way out lots of free play on lever works best. Have someone watch top resivior for bubbles and overflow. G'luck!
Dont forget, just a tiny "seen it" for you. the rubber boot on the master cylinder is to keep dirt out, but dirt can get in there, and the main "pushrod" could have dirt keeping it from resting against the circlip, if not clear up against the circlip, which is at rest position, the tiny orfice that lets oil into the line or out of the line into the tank, doesnt line up, aka is closed... make sure you have free play, you can always do it the old way, pump oil from resivior to the slave cylinders, it just takes longer and can again only happen if the master cylinder plunger is aligning the hole up when lever is released fully... Be patient, grasshopper it should go...
This may be the issue Sting. I took the line and banjo bolts off to check for obastruction after talking it over with NMTrailboss at San Yo yesterday, and they were clear. So i put the bottom banjo bolt back on adn opened the nipple and put fluid up through it with the syringe, and that was fine, fluid came out the top. so I re-attached the top line to the master cylinder and re installed the pushrod and now there is no way to get fluid up through the bottom. I think I have the pushrod lined up right, I ran out of time last night. I think it is definitely an issue with the master cylinder. will the lever still travel if the pushrod is not lined up right? There is no fluid entering the cylinder form the reservoir either as far as I can tell.
