QuestionQUESTION: The brakes on my new 75 1500 were squishy and I could leave no rubber. Received the EZbleed from Victoria but returned it because there was no 3.75" adapter for the reservoir. Started to bleed the 2-man method. Owner's manual says to keep pumping until bubbles are gone, then close nipple. Haynes says to close nipple after each pump when pedal in down and repeat after each stroke. I locked brake adjuster as required by both. Hand brake was released. Tried Haynes method first. Some bubbles and fluid came out, then fluid quit coming. Only air comes out of the tube into the glass jar now. Tried Owner's Manual method. Same result, only air is being expelled into the jar. No fluid is coming out of the system. Tried this on both back wheels with the same result. What am I doing wrong? Also Owner's Manual says NOT to push pedal all the way down. Haynes says to push it all the way down. How can I have the fluid come out of the nipple? I also want to replace the entire DOT3 with DOT4.
ANSWER: I first have to ask if you are keeping the master cylinder reservoir full; its easy to forget to check its level when trying to bleed, and then the master cylinder is sucking air rather than fluid.
Depending on how large the "air bubble" is in the system, you may have to refill the master cylinder several times with either new fluid, or, if clean, fluid from the caliper or wheel cylinder you are attempting to bleed, until you get the air out.
Always start with the farthest point first (passenger rear), then the next closest. If you can do the two man, the preferred method is open the bleed, press & hold the brake pedal, close the bleed, release the pedal. The press of the brake pedal forces fluid down the line & out the bleeder.. The release of the pedal sucks new fluid from the master cylinder reservoir into the cylinder. If the bleeder is open on the release, it will suck air from the wheel cylinder (open bleeder), rather than suck fluid from the master cylinder, as that is the past of least resistance.
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QUESTION: I have followed all of your instructions, kept the master cylinder topped off and closed the nipple when the pedal was down. But then I noticed a pool of fluid collecting around the master cylinder. I also bleed the front brakes and they bled fine. Was I sucking air into the lines from the master? I have sent for the rebuilt kit. Should I replace the entire master?
AnswerYou were likely sucking air from the reservoir before.
Where is the fluid coming from that you are seeing below the master? From over-filling the master or is it coming from a connection, or where the reservoir meets the iron of the master cylinder?
If you can bleed the fronts, and still get air at the rears, then trace the pipe from the master to the "T" or 4-way that splits the front from the rear pipes, and check the connections that they are tight and not leaking.
As long as the bore on the master cylinder isn't pitted and corroded, rebuilding the master is fine. You only need to replace the entire unit if the bore is too beat up to make a good seal anymore.
