My car does not have a power booster, only the master cylinder.

Problem: I have tried to bleed my brakes twice already and I have had trouble after pressing the brake pedal repeatedly. After I get past the back brakes, my pedal sinks in and I can only press it in about one inch. It's as if the master cylinder broke or something. By the time we get to the front brakes we get much less fluid out and the pedal is pressed in about 5 inches giving me only about 1 inch to pump the pedal.

What I did: I bench bled the master cylinder. Then I put the lines onto the master cylinder and the proportioning valve (everything is new). I then raised the car and began to bleed the brakes. My friend was at the bleeding end and I was pumping the brake pedal. NOTE: I was pumping continuously (only about two inches deep so I wouldn't break the MC) and not on and off like the Chilton's manual said. My friend said this wasn't necessary anymore.

Question: What am I doing wrong? I have already tried two different master cylinders and each time I run out of "pedal room" towards the end of the bleeding process. Do I just need to start the car?

I have read that I should never step down on the pedal all the way when bleeding the brakes because that will mess up the MC. However, I also heard that I should step on them all the way then allow the other person to open the fluid vein to bleed it, then he would close the vein and I would release the pedal.

Has anyone done this or can they give me any idea. Thanks in advance.

 

This is pretty much how I do it

http://www.youtube.com/watch?v=LgxMfQUMdJY

 

Also what helps after replacing parts that leaves a lot of air in the system, is letting the fluid "gravity feed". Remove the reservoir cover off the master, open the bleeders at all 4 wheels, and just let it run out on it's own. If you don't have hoses to put at all four wheels at once, then do one at a time so you don't make a mess. And keep an eye on the fluid level so you don't suck air back in. After they run clean, close off the bleeders and bleed each one individually as shown in the above video. Gravity feeding gets most of the air out, and cuts down a lot on the pumping process.

 

+1 on gravity feed. I cut the side out of antifreeze jugs and use them for catch pans. Another option is a cheap vac pump from the local parts store. It will suck the MC dry so be carefull. Only need one person for that.

 

You wont hurt the MC by pumping it all the way down, and you wont have full pedal until you get all the air out anyway. Just keep at it until you do, and don't let the pedal up EVER with the bleed valve open. It just sucks air back in , and you're doomed then.

 

DOOMED! I say! DOOMED! MUHAAAA!


Just messin with ya Vall.

 

Thank you all for your suggestions. I can't get started until this weekend but I will let you know what happens.