Have a 2002 Cavalier that I just replaced all of the calipers and cylinders, as well as pads and shoes. Noticed that when braking the car slightly pulls to the right. Re-replaced the driver’s side caliper thinking I got a defective part, but problem is still there. When bleeding that caliper I get very little fluid to flow. Even with a hand vacuum, it builds a lot of suction, but still little fluid flows. I checked the line from the pressure module to the caliper and its solid, no leaks or holes. However, I put some compressed air into the hole of the brake pressure modulator (for that particular line) and the air seem to flow through and could see some air bubbling in the master cylinder reservoir. My question is, is the fact that there is no pressure in that line from a bad master cylinder (never been replaced), or is it a bad Brake Pressure Module? Any help would be greatly appreciated.

I would start at the master cylinder crack the fitting on the side and check for pressure first. This is done with somebody having their foot on the brake pedal after pumping it up.