As many have reported the same issue, I have replaced all four brake calipers at least twice over the last 8 years on my '05 F-250. I don't put a lot of miles on it, and I live in the Pacific Northwest, and it does rain here, if you have not heard. And the pickup is parked outside, but covered - and now in a Costco carport tent. So this time after taking off both front calipers which have been sticking, I did some diagnostics. I removed the pistons from the right front caliper, and measured the bore diameter after cleaning it up. The bore measures exactly 2.360". Then I measure the OD of the removed piston which had been sticking. The inner end of the pistons measures 2.358-2.359" diameter. OK, tight fit, but acceptable, I guess. But the outer portion of the piston near where the groove for the dust seal is, measures 2.375 to 2.379"! No way is that going to move freely in a 2.360" bore! In fact, I had to blow the pistons out with about 100 psi of compressed air, and they did not budge until they came out suddenly with a bang.

This caliper was a replacement from a rebuilt caliper, from NAPA as I recall. I would love to track down the manufacturer of this piston, as it is just damn unsatisfactory for these phonic pistons to swell like that. The swollen piston has an "K H" on the end embossed into the phonic. I did a Google search and came up with Kelsy Hayes, but as far as I can tell, that was a company which made disk brake calipers for the early Mustangs. There appears to be a company still making Kelsy Hayes calipers named Haldex, but I am not sure if they are just a re builders of KH calipers.

I had hopes of rebuilding my calipers with new pistons and seals, but after taking a look, I decided the most efficient way was just to order new loaded calipers. I ordered the Callahan CCK11690 Front Premium Loaded OE Calipers from Amazon. The rears - also from Callahan were replaced last year and so far are trouble free. Its interesting, one of the replacement fronts from Callahan was a rebuilt TRW/Ford Caliper. The other looked like a newly manufactured caliper without the TRW/Ford markings. We will see how they do.

If anyone knows who manufactures the K H pistons, I would love to know. Also, if anyone knows of a good source for calipers / pistons which will not swell over time, I would love to know.
Thanks!
Doug

 

Kelsey Hayes brakes weren't just on early Mustangs. K-H calipers were OEM issue on my 2000 F-550. At one point many years ago, K-H supplied up to 85% of all US domestic brands of automotive brakes and wheels.

Kelsey Hayes was acquired by, and divested from, several other companies, most notably Varity, which was acquired by Lucas, before TRW acquired the brake division at the turn of the millennium. Hence it is not surprising to see TRW on some of your parts.

ZF Friedrichshafen AG now owns what was TRW and the Kelsey Hayes Group of Companies.

Due to the changing of hands, leveraged buy outs, mergers and acquisitions, and even more confusingly, license agreements where a well known brand name is licensed by a lesser known manufacturer, which misleads the consumer to believe that they are getting a part from an old well known manufacturing brand they trust, when in fact, they are getting only a label of that brand, on a product of an unknown and unknowable import manufacturer, who merely, and shrewdly, paid a license fee to the holder of the well known brand name, which may not manufacture anything under that brand name any longer at all, because it is more profitable to simply license out the use of the brand name.... I don't know if you can find the right person to yell at for not making the phenolic pistons sized to what you believe they should be.

Automotive parts is a very murky and mercurial business.

If any research or investigation would be useful to undertake, consider a searching for best practices of brake maintenance, which is something you actually have control over. We have no control over how brakes are manufactured, nor any reasonable assurance of knowing who actually manufactured or re-manufactured them.

Kelsey Hayes was a great name in braking in the annuls of American automotive history. The Kelsey Hayes brakes on my 2000 F-550 are original issue, as installed in 1999 on the production plant floor, and 22 years later, the exact same OEM calipers, rotors, pads, and pistons are all still in service today. Not one brake job required. Periodically, I lubricate the slide pins, and change the brake fluid, using regular Motocraft DOT 3, per the owner's manual recommendations.

 

Replace the brake hoses. All of them. Not just the hoses at the calipers but also the rubber one that mounts above the rear differential.

-- Dave

 

It seems from 2013 forward the brake caliper freezing stopped. It had to be a design issue.

 

Y2K, thanks for the background history. Yeah, doesn't look like there is much change of contacting the company who made those pistons, and getting anyone to listen.

As for your suggestion about driving habits, I am not hard at all on the brakes. In fact, I don't have to drive the truck much at all for these pistons to swell. However, I know how to solve the issue for good - buy a new house with a shop and store the truck inside in a climate controlled environment. But that is just not going to happen any time soon. Again, this is an example of a bad design and manufacturing processes. Even the original Ford parts have this issue.

 

Dave,
I am not seeing how the brake hoses could possibly contribute to the piston's swelling to a larger diameter from the caliper bore, thus causing them to stick.

Doug