Ok, so I have done all kinds of brake projects back when I was in a shop, but once again, Im seeing some problems I havent come across before.
I took started working on the brakes on the camaro. They look like they had nearly new pads on them, but it wasn't stopping like it. So I took everything apart, cleaned all the surfaces of the brake pads (ie. setting them on the ground and scratching all the loose crap off), banged off the brake dust from the rear drums and wiped it out, and sprayed down the drum hardware. I reset the rear brakes to catch a little sooner.
Now here is where I think I messed up. I know this is a risky thing to do, but hasn't let me down before. The brake caliper and pads never quite fit back on after you take them off. So I normally take a C clamp and push the piston back in enough to get them around the rotor. Again, I know you can harm the brake system this way if you do it too much which is why I think this is what did it.
I put them back on, and bled the brake lines with all new fluid. Afterward, I realized it was spongy and wasn't holding firm when I applied the brake. So I thought my action with the C clamp caused the master cylinder to bust. Which Ii have seen happen before when someone else tried my little cheat and went too far with it. So I replaced the master cylinder, bled the brakes again until a little after I was sure all the air bubbles were out.
Now it is much more firm than before. But if you have done brakes, you know when the car is off, the pedal should travel no more than an inch. I still have a couple inches of leeway before it catches like that.
I read Camaro69's advice on one of the posts on here about if the rear brakes were low, it will have some travel. Now, it was fine before I started this project as far as the brake pedal travel goes, but I took it into consideration anyhow. I watched the brakes as someone applied them. The rear brakes dont move at all with the brake pedal, and i know they are only 30-40% brake force from the pedal, but I feel I should still be able to see them move a little. With the e-brake, the one side works fine, but the drivers side hardly moves at all when fully pulled.
I pulled the abs relay thinking maybe the abs system is faulty, still no go. I can see all the brake lines moving from pressure when the brake is applied, everything is firm on the pads to the rotors. There are no leaks anywhere. Fluid is clear all the way back, so there arent any clogs.
So I have no idea whats next. Either I somehow threw my brake pedal off, or maybe the brake booster isnt working properly?
I dont really have experience with the booster. I know when you push down the brake, it pushes out a rod that pushes the master cylinder. Thats all I know besides its a huge black box on the firewall.
I think that is all the information I can possibly give. Any ideas?

 

Pushing the piston back in is a pretty common way to do it, and I do it too, but you need to make sure you unscrew the cap on the brake fluid reservoir. Otherwise, the fluid in the line has no where to go when you go to press the piston in.

I'm not the best at diagnosing brake problems, but I will ask: does the pedal get stiff if you pump it with the car on? If it doesn't, then i think that would mean there is some sort of leak or failure in the booster no? Again, not 100% sure on this issue, sorry

 

I did take the cap off the reservoir when I did it. I had it off the whole time when working, except for when I bled the brakes the second time.
Now I have tested it with the car on before the new master cylinder and it went to the floor. I have not tested it yet with the car on because I am waiting for some gasket maker to dry around the egr pipe on the grommet since it keeps falling out.
I will test that tomorrow around 5 or 6.
Usually when doing that little trick, it hurts the master cylinder but the brake booster is what Im thinking to since thats all thats really left. But Im not sure how it works, how to go about taking it apart, etc. to check it out. Let alone change it.

 

A couple questions. When you bled the brakes, did you do the rears too? Could be air in a rear line if so, but you working on the fronts wouldn't have done that. Bleeding procedure is to do the furthest to nearest...right rear-left rear-right front-left front.
The drivers side brake shoes not moving with the parking brake has me wondering if perhaps your cable(s) are rusted in place and the shoes are left extended out. Might want to check inside the drums to make sure there isn't tension on the pivot arm that the cable attaches to.

 

I did do the rear brakes when Ii bled the system, and I did start in the rear. Will the ideal of which side of the rear going first matter much? Ii did drivers rear, passenger rear, drivers front, passengers front. which was a little a** backwards but I wasn't thinking on that part clearly. haha.
Ill check the cables and pivot arms tomorrow then on the rear brakes. It started to rain here now.

 

Using a c clamp shouldn't break anything unless it was already bad. Next time buy a brake spreader $10 from a parts store. Does the same thing but a lot easier and evenly. Y did you bleed the line when you already used the c clamp? I would bleed it again you want to start from the line furthest out. starting from passenger rear then driver rear, passenger front, driver front. You could've got some air trapped further up. Hope full not in the abs.

 

I used the c clamp to put the caliper back on. So I bled it when everything was back together. Ive bled it about 3 times now and each wheel was done about 5 times per revolution. So all air should be out of the system. I did take the abs relay out, so it shouldnt have to do with the abs at all. Tomorrow Im going to inspect the rear brake cables and hopefully get another brake booster and replace mine. If that doesnt fix the problem, Im really at a loss.

 

Save your money. The brake booster just assists in moving the master cylinder so you don't have to exert as much manual pressure with your leg. If the pedal goes limp to the floor, that's a hydraulic issue. When you're inside the rear drums, take a look at the wheel cylinders (that cylindrical looking thingy that pushes out on the top of the shoes), and see if they or the surrounding area looks wet. That would mean it's leaking and possibly sucking in air on the back-stroke.

 

Im pretty sure it was still dry when I was checking them out last. But I will double check. Im not sure how much online stuff you can actually believe, but I read somewhere that the valve for the booster can fail causing this problem. Is there any truth to that?

 

One thing I lost track on reading through here, is, have you tried bleeding the brakes using the correct procedure? Passenger rear, driver rear, passenger front, driver front? If not, I would try that first just to rule out any possibility of air being in the system.