Grabbing brakes

I'm new here, (and not that experienced of a mechanic) so I sought the advice of those who know much more than me.

I was in a fender bender (someone a few cars up cut over at the last minute for an off-ramp, causing everyone in front of me to slam on their brakes. Let's just say I didn't stop in time.

After the collision, I noticed that I could no longer coast well, as the brakes weren't releasing. Here's what I've done so far.


Changed the Brake Master Cylinder (something internal sticking / grabbing?)
Replaced the Rotors (Theory, the brake piston is extended too far and grabbing / not coming back in when the brake pedal is released)
Replaced the brake pads (Same as above. If I keep the piston further in the "socket" it won't have as much trouble)


After making those 3 changes, it seems like it's still grabbing. The car has 250+k miles on it, so most of that stuff needs replacing anyway.

What else should I look at? I'm thinking new calipers (for the new piston as well). Brake Booster? Brake Tubing? Any help would be greatly appreciated.

Thanks,

Wes

Which brakes are grabbing and rubbing? Just one wheel? Or both front wheels? The back wheels?
The way to tell is to apply your brakes hard, when stopped. Then drive for a couple of blocks when the car is cold. Then very carefully feel the drums and rotors. They should be cool to the touch. If one or more is hot, then that's the dragging brake(s).
Since it was a collision that produced this damage, look for damaged and flattened steel brake lines. Such damage means the brakes will release very slowly, or not fully release at all.

Also, if you just have one wheel that's dragging, consider replacing the flexible brake line for that wheel. These lines can collapse internally, causing the same problem.

Thanks for the reply MagicRat.

It is the front brakes which are grabbing (equally, as there is no pull when I press down while moving), the back ones spin freely when they are jacked off the ground and no parking brake engaged.

I replaced the brake pads and rotors, then drove the car around the block. When I got back into my garage, I came away with 3 observations (still).
1) The car didn't coast as well as it did previous to the accident.
2) The brake pedal was high and hard.
3) After getting out of the car when I got back to my garage, the brakes smelt / felt warm.

I'm going to try replacing the calipers tonight (maybe damaged the pistons). I'll take a look at the brake lines too.

Thanks.