no brake pedal

About 3 weeks ago my brakes were getting more and more spongy and I checked the fluid and it looked very low, so I filled the master cylinder with fluid, which worked for about 2 weeks, then it started feeling spongy again, but when I checked the fluid, it was fine. A couple days later as soon as I went to drive to work, all of a sudden I had no brake pressure at all. The pedal went all the way to the floor, followed by a slight popping/click and the brake light comming on. I replaced the master cylinder, bench bled it, and its still doing it.

Maybe air got into the lines when the fluid was low? My dad says its the vacum booster, but I want to double check before I spend the $100 for that part.

sounds to me like ur rear wheel cylinder blew out.look at ur rear wheels and see if the back side of the tire is wet.

would that cause my fluid to leak or drain? Its still full from when I changed the master cylinder. I'll check the tires though. Thanks.

Without taking off the back tires, there is no sign of fluid, or any wetness. Its been about 2 weeks since the van has been sitting there. Could the fluid have dried up? And how might I tell the cylinder is blown once I get the back drums off?

(with the engine off) look at the level in the master cylinder reservoir, then give the brake pedal a good maybe 20 pumps. it should become stiff after the 3rd or 4th pump. if it doesn't, then check your level again. if the level went down, follow your brake lines and see where it's leaking from. if your level stayed the same, and your brake pedal is still soft, you may have a master cylinder issue

well once u take off the drums u will notice everything wet with brake fluid.once it is on the brake shoes then it is time to replace them because the fluid destroys the shoes.also check to make sure the front brake lines didnt blow out.that would spray fluid everywhere in the wheelwells.

did you ever get this problem fixed. i think i have same problem, and like you i don't want to buy booster. when i push down my brake pedal while at an idle my idle goes up.

yes i did get this fixed finally. Both of my rear wheel brake cylinders were bad. We replaced the shoes, and cylinders and that fixed the problem. I have no idea about the idle thing though. I would think that the brakes should have nothing to do with the idle, so i am stumped on that one.