I just recently replaced the brake pads on my front wheels. It had been braking very slowly. After replacing them, I tested it out, and the brakes felt spongy, and I read here that I should bleed the brakes. I started doing that, read some of the how to's here, and found numerous videos on youtube and also read the repair manuals proceedure. I'm doing it as it says, but its being very very slow. Using the two person method, with one person in the car and one person opening and closing the bleeder screw, we had to do it this like... 15 times before any fluid showed. (started on the back tires because I had taken the brake pads off to ask a mechanics opnion on their condition, and was told they were fine) After maybe 10 more times we got to the point where there was no bubbles, but still no more than an tbls (if that) of fluid comeing out at a time. Now working on the right front, and using a mighty vac, I sat for 15 mins with a constant vacuum, for the first 10 minutes there was no fluid, just air, then a slow intermittent trickle of fluid. I haven't had to add any fluid to the master cylinder yet.
What am I doing wrong, I've opened the bleeder screw plenty, and then some to make sure I was allowing enough through. If the mighty vac wasn't loosing preassure while it was open I might think thats it, but it's definatly pulling air, and a tiny amount of sludgy brake fluid.
Is it suppose to be this slow? Or does this mean I have a collapsed brake line(s) and is that easy to fix?

 

Did you open the cap on the master cylinder under the hood? Basically, whenthe guy in the car pushes on the brake pedal, it pressurized the system so when you open the bleeder it should come gushing out. Then you tighten the bleeder and the guy lets off the pedal it will suck in fluid from the master cylinder so you'll need to top off the cylinder n

 

On a side note, When the brake pedal is depressed, I can hear a hissing of air from the area of the Master Cylinder, but I can't see any leaks any where. Would removing and checking (and possibly replacing?) the master cylinder help with this?

 

I have opened and looked in the Master Cylinder, and the level is fine. Fluid definatly doesn't come gushing out, that's the problem. When brake pedal is pressed and when it's released, I can hear air hissing around the Master Cylinder, so maybe the Master Cylinder is clogged? I'm not sure, and I'm getting to the point of tearing out my hair.

 

It is very odd that all you did was replacing the pads and you get air in the brake system?

If air is in the master cylinder now for whatever the reason and is not pushing fluid, you may need to prime the master cylinder first before you bleed the rest of the system.

 

Well, I tried to prime the master cylinder, not sure if we were doing it right, but I found where air appears to be going in and out, right where the master cylinder mounts to the power assembly (booster?) when the brake is pressed and released. Is there a gasket behind that, that maybe needs to be replaced? Not much about it in my manual.

 

I was replacing the pads, thinking that was why my brakes were not working very efficiently. The pads were actually not that worn. So the air leak was probably already present and causing my problem and the pad replacement was coincidental.

 

Remove two lines coming out of master cylinder.
Attach clear tubings to out ports.
Rout open ends into reservoir.
Fill reservoir till tubes are submerged.
Pump till there is no air coming out of ports.
Reconnect those two lines and proceed with normal bleeding procedure.

I don't think there is any gasket, but O-rings are used on brake cylinders. In any case, you want change master cylinder if you are thinking of changing O-rings or "gaskets". I don't know if IPC will break down that much on cars.

 

If the pad were not that worn, the replacement was not needed.

You may had/have air in the system to begin with. You feel it spongy. Air can be bleed out.

You may had/have leaky piston or debris on piston assembly. You feel the pedal go down slowly as you step on it. You need new master cylinder or need flush job to clear debris.

These are two different things and require different work, so to speak.

 

Sorry if this sounds stupid, but... how do I connect tubing to out ports? They are female fitting on the master cylinder.