2011 F550 Destroying rotors

So we've been servicing a local tow company's Ford trucks. He has several 450's and 550's in his fleet. Having a lot of issues with the 2011! Truck has about 21k miles on it and its eating through brake pads in the rear right like no tomorrow. At about 12,500 miles the inside brake pad wore through into the rotor and destroyed the rotor (but the outside pad was only about 1/2 way work out) Ford said it was all normal because it was being used as a tow truck.... and he came to us and we replaced the rotor, and put on a new set of pads on the both the left and right sides. All original Motorcraft.

Well we're at about 21k Miles and the truck is back here today with the same issue. The inside pad is almost completely gone and wore through the rotor yet the outside has more than 50% life left on it.

We called our local ford dealer and they said that it is normal for it to wear on the inside more than the outside because that is the side of the piston on the caliper, seems to us we have a bad caliper, any ideas????


Inside of the rotor again is destroyed......


Yet the outside looks fresh

Are the slides moving freely on the caliper?

Slides are moving freely. We replaced the metal slider guides last time and lightly used caliper lube on it.

Maybe a chance the proportioning valve could be messed up?

T for the brake lines on the rear axle possibly plugged and sending all pressure for the rear to just the right rear?

But why would that make only the Inside wear out Matt?

Any thought of doing an aftermarket brake set-up. Expensive in the beginning but would be cheaper than going through this so much i would think.

TrueBlissCustoms said:

But why would that make only the Inside wear out Matt?

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Shoot sorry I missed the part about just the inside.:doh:

The only thing I can think of as well would be the slide pins seized up, but if they are moving freely like you said that kills that idea.

Actually, there is a chance there is somthing inside the slide pin holes holding up the slide pin from going inside the caliper bracket all the way, I dunno just a thought?

What aftermarket out there avaialble for DRW 450s and 550s? If the caliper is the problem, we may be able to talk to him about changing it out. But what we're wondering is if there are any other trucks out there with any similar problems?

TrueBlissCustoms said:

What aftermarket out there avaialble for DRW 450s and 550s? If the caliper is the problem, we may be able to talk to him about changing it out. But what we're wondering is if there are any other trucks out there with any similar problems?

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Maybe a SSBC kit, ill have to check into it but that might be a good option. There has to be someone making something for it.

SSBC doesn't have anything that new on their site... So I'm guessing not...

I've heard motorcraft has had a bad batch of brakes.

Does the same driver always use this truck? Maybe the parking brake is sticking?

Parking brake wouldnt wear the pad and rotor down though,

The parking brake is a seperate set of brake shoes

Matt_P said:

Maybe a chance the proportioning valve could be messed up?

T for the brake lines on the rear axle possibly plugged and sending all pressure for the rear to just the right rear?

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Jack it up. Leave the tire off the guilty side. Put.jackstands under the rear axle. Watch and see whats happening. Short of that, id be takin a dremel to the slides to make sure they are adequate. Lube them again. Cross your fingers! Id take the previous suggestion involving the jack stands. You might have a bad caliper that is binding.

So we put in another set of brand new rotors (customer bought left and right side brand new, brand new pads all from motorcraft. I just jacked up the rear of the truck, and let the rotors spin freely and then brake, then about 1000 rpm and brake, 1500 rpm and brake, seems fine. When you hit the brake and let go the little separating tension springs are working fine and they push the pads away from the rotor. I'm crossing my fingers and hoping this time its gonna fix it.

fine69 said:

Does the same driver always use this truck? Maybe the parking brake is sticking?

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He has about 12 drivers, and all his trucks are running 24/7 so no the drivers are almost never consistently on 1 truck.

kinda an odd ball, but i did have a 09 f350 of a buddys the piston would get cocked when pressure was realesed was hard to find i got pissed of and pulled the caliper apart and there was some metal shavings from assembly i believe that were making it hang. just throwing it out there. new caliper fixed it

I have seen this on 2000 up trucks ,, just a hung caliper

they also tend to crack pistons and hang

Pardon my ignorance, but what type of calipers do these heavier trucks use? 2 inboard pistons? Just curious.

The only time I've run across this issue when all the slides checked out OK, it was a bad caliper where a piston wouldn't settle back into the bore. Everything seems fine running it back in with the caliper compressor when changing pads but in regular operation they would hang enough to eat the inboard pad.

I also had this happen to me on my 98' Cobra but that case was related to the parking brake mechanism in the caliper.

Had one on a f350 do it but the pistons on the rear caliper would seize up and not slide back in. Toasted the inner pad and smoked the caliper and rotor.