I just put new parking brakes, rotors, shoes, and brake pads on my back wheels. When on a hill, i put my parking brake on and it rolled still. Why did it do that with new parking brakes?

 

Truck details, please.

 

2004 ford f150 lariat 5.4L 4wd automatic

 

Did you adjust the star wheel on the shoes? Is there a bind/seize in the cable that runs along the frame?

 

x2 on the star key adjustment. Accessible from underneath with the wheels on via little rubber block-offs.

 

probably the adjusters as others mentioned.

Also double check that the cables didn't come off the brakes. I've personally found that on my old truck

 

The part that the cable connects to can be seized that moves the shoes apart from one another. Most of the time this part will not let the shoes release after emergency brakes are applied. Free up the pivot of the 2 pc's and lube with never seize compound. This only if everything else checks out as mentioned above!