No brakes/pedal goes to the floor
 

Recently bought 1999 Dodge 2500 Van was pulling to the right(hard) when the brake was applied(brake and abs lights on dash also). I bought a new left front caliper thinking the old one was set up. Then the pedal went to the floor. I bled using gravity bleed as well as having someone pump and hold the pedal. Bled more and more. Same problem...Some pressure but pedal quickly drops(now abs and brake lights are off). Checking for any leaks all I could find was a tiny bit coming from the master cylinder, the power booster didn't hold pressure and was like it had no assist removed either with vacuum hose attached and vehicle running. So both the master cylinder and the booster where replaced, and the same problem continues. Rear brakes have been adjusted and all lines bled. I'm thinking abs or proportioning valve. But why would that be when all this started with a caliper swap. Thoughts? Hate throwing parts at something not knowing.

Pedal going to the floor is a leak somewhere. When replacing caliper did you get the right one for that side? Bleeder screw should be at top of caliper. When replacing master cylinder did you do a good bench bleed before installing? It can trap air once in vehicle due to the front being slightly raised. Use a power bleeder to make sure there is no air in the system. If you replaced master cylinder and then bled the brakes it can take several attempts to get the air all the way down to caliper bleeder. This means you will pull quite a bit of fluid before the air makes it. I got tired of pumping the power bleeder to get a tiny little squirt out, I installed a brake vacuum pump from an Audi with a cut off switch at 20 inches of vacuum to replace the pumping and can do a brake flush in minutes. Also with not knowing the history of the vehicle a brake fluid flush might not be a bad idea. Also bleed it from farthest away from master cylinder to the closest. Pass rear, driver rear, pass front and then driver front.

Thanks XAZA... The caliper was the wrong one. Apparently the box was correct for the drivers side but it was a right side caliper.