06 HHR front brakes apply themselves, this car has no abs. I've changed. calipers, master cylinder, brake booster, pads, rotors, and front brake hoses.

the problem will be in the master cylinder --blocked compensating ports not releasing the fluid back to the reservoir

Bleed your brakes. Start with the right rear then left rear then right front then left front.

the reason may be : the brake booster is lack of pressure.

Did you replace the lines when doing all the work, the lines are the cheapest part of it all

just because the rotors are new dosen't mean they come out of the box 100%,you might have one that is running out,causing the pulse,most pften it is recommended to have them turned on a brake lathe prior installation (saves you the trouble of doing the job twice)

I had the same problem and replaced both calipers with no change, I figured it was the master cylinder. When I pulled off the master cylinder I saw the vacume booster had about 2 cups of brake fluid in it which leaked from the front of the master cylinder. I replaced master cylinder and vacume booster and brakes work great now.

bleed the brakes again starting form the longest line back to the shortest
if you have been getting a pulsing feeling at the pedal under normal brakes you have warped rotors that need replacing or machining
under normal brakes the abs is not effective and it is only under sever brakes that you will experience the pulsations at the pedal

SOUNDS LIKE YOU HAVE A BAD BRAKE BOOSTER CHECK AND MAKE SURE YOU HAVE GOOD VACCUM TO IT WHEN YOU TAKE THE HOSE OFF SHOULD HIS THE BOOSTER IS THE ASSIST FOR THE BRAKES CHECK THAT AND GET BACK TO ME I HAVE ALSO SEEN ABS TROUBLES

Disk brakes are automatically self adjusting. If you have too much travel in the pedal, bleed the brakes. Let us know if you need the procedure.

YOU NEED REMOVE A LITTLE BRAKE FLUID FROM MASTER CYLINDER.THEN YOU RAISE VECHICLE SAFELY.SUPPORT IT WITH JACK STAND.MAKE SURE VECHICLE IS ON LEVEL SOLID GROUND.REMOVE TIRE OR WHEEL.THEN YOU NEED A LARGE C - CLAMP.PLACE C - CLAMP OVER BRAKE CALIPER AND BRAKE SHOE BACKING.TIGHTEN C - CLAMP JUST ENOUGH PUSH CALIPER PISTON BACK IN CYLINDER BORE TO REMOVE CALIPERS FROM ROTORS.TO REMOVE BRAKE CALIPER YOU NEED 2 OPEN AND BOX END WRENCHES ONE TO HOLD CALIPER SLIDE PINS AND THE OTHER WRENCH FOR LOOSEN CALIPER BOLTS.THEN YOU REMOVE CALIPER AND REPLACE FRONT BRAKE SHOES.IF YOU NEED TO REMOVE BRAKE ROTORS JUST REMOVE THE BRAKE CALIPER CARRIER SUPPORT BOLTS THE REMOVE THE BRAKE CALIPER CARRIER SUPPORT THEN REMOVE ROTOR.YOU NEED TO REPLACE BOLTS WITH NEWS AND USE LOCK TIGHT.THEN YOU PUT IN NEW BRAKE PADS IN CALIPER PUT CALIPER BACK ON SUPPORT CARRIER.REPLACE WITH NEW BOLTS USE LOCK TIGHT THEN TORQUE BOLTS TO 26 FT LBS.MAKE SURE MASTER CYLINDER COVER IN PLACE.WHEN YOU FINISH REPLACING BOTH FRONT BRAKE PADS PUMP BRAKE PEDAL TO SEAT BRAKE SHOES AGAINST BRAKE ROTORS SO YOU WILL HAVE FIRM BRAKES WHEN YOU APPLY THEM. THEN CHECK YOUR BRAKE FLUID LEVEL IN MASTER CYLINDER MAKE SURE ITS NOT LOW. MAKE SURE YOU HAVE FIRM BRAKES BEFORE DRIVING.IF YOU HAVE ANY PROBLEMS CHANGING FRONT BRAKE PADS YOU CAN GO TO ANY AUTO PARTS STORE AND BUY A HAYNES REPAIR MANUAL.