The wife and I ventured out last Friday evening to run a few errands. When we returned to the house and pulled into the garage, we both smelled burning brake pad. I felt the rear wheels, the drivers side was too hot to touch.

Dragging brake caliper.

OK, been through this before. I got online and reserved a drivers side caliper and a set of pads at NAPA. Saturday morning I removed the caliper. Much to my surprise, one of the caliper pistons was broken into multiple pieces.

I took the offending caliper to NAPA and picked up the new caliper and a set of pads.

Side note - NAPA seems to think the 2007 trucks have calipers that mount in front of the axle, not behind the axle. They will try to sell you a passenger side caliper and tell you it is a driver side caliper. It will bolt up fine, but the bleeder valve will be at the bottom of the caliper instead of the top. You'll never get the air out of the caliper.

Got back home, bolted up the new caliper and pads, then bled the system. All worked well.

I decided to throw new pads on the passenger side brakes as well, since I had 2 remaining. I took off the passenger side caliper, much to my surprise I found a cracked and broken piston on that side also! Another run to NAPA to pick up another caliper. Installed, bled the system again, all working well.

Now, I have never seen a cracked and broken caliper piston like this, let alone one on each side of the rear axle. Any idea what might have caused this? About a year ago I had a shop install new backing plates. The pads and calipers are about 3 years old, same shop installed those.

 

On a few of our work trucks (f150-F550) I have seen them break up like that. I always figured it was due to the heat, stress and abuse since they are always pulling trailers or something in the bed. I had some issues with NAPA brake parts lately and since have went to Ford parts and so far so good.

 

I have been using NAPA because around here the winter salt will seize your rear calipers no matter what you paid for them, $70 or over $200.

 

Yeah, ditto the heat thing. I had one caliper hang up that I couldn't get to fix for a few too many miles, it was pretty skanky - toasted and one of the pistons was cracked into a couple pieces. I was surprised it didn't leak.

 

Just buy calipers with a good warranty at a close auto parts store, because you're going to be replacing them in a few years. I've never replaced a caliper for having a leak. They always have a seized piston, or a slide pin rust-welded in place.

 

I have done my RF twice under warranty and my RR once under warranty and once just out of warranty. Not sure what the deal is, but it sure is annoying. This is all with Motorcraft parts.

 

Never seen a broken piston...

 

Before you replace calipers and lines examine the inner pad. The pad ears get frozen in the caliper even with the SS spring clips. Now they won't retract and stay on the rotor. Make sure the channel in the caliper is clean. Install the spring clip so it fits tight on the pad and is good in the caliper groove. Put silicone grease between the spring and the caliper and the pad and spring. Now install the pad. See if it floats nicely and moves in and out. If not make sure the caliper groove is level with a file. You may have to file down the ears a few thou as well to get a good fit. Compress the caliper pistons and feel for resistance. That usually indicates a bad caliper. Even if all you replace is the pads you should bleed the system. It's likely overdue for fresh fluid.