Owned by phenolic piston

Mother is away for a week, her 2009 WK has 82K miles, brakes are down to about 1/3, good opportunity to throw some new pads on.

Front went fine, caliper lifts off, pads remain on bracket.

Rear caliper holds the pads, as I went to pull the caliper away from the disc with screwdriver the pad stayed in place, pushing the retaining prongs in the piston against one side taking a chunk out of the phenolic piston (WTF, first time I saw something like this... only dealt with steel or SS in the past).

In hind-sight I could have avoided this by slightly compressing the piston instead of just trying to pull the caliper off (there appeared to be no groove, normally pads slide out with a slight tug).

Anyway... live and learn... replacement Mopar caliper is only $50, could be a lot worse.


CCSP, don't worry, she left me me plenty of Sunny-D for the week... yum!

We had a 2012 F350SD in the shop with a hard pull problem. Some how this guy got the brakes so hot the phenolic pistons on one caliper disintegrated. There were huge chunks missing from them. The odd part is the rotor was not damaged, or blued.

Are you going to replace calipers on both sides?

Jays89YJ said:

Are you going to replace calipers on both sides?

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Don't plan to. There is nothing wrong with the other and it's only three years old, maybe if it was an older vehicle.

If anything, I prefer to leave as much brake hydraulics alone as possible to minimize leaks (I hate brake hydraulic fittings of any kind... flared, banjo, etc).

Hubjeep said:

Mother is away for a week,

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Party at Hubs!

Friend's WK had a seized caliper. We took it apart and found one of the pistons to be cracked. Ended up replacing the one caliper, both rotors, and pads.

TJmobile passenger caliper siezed one day and turned the rotor blue and gold. I thought my aluminum rims were to melt. Replaced everything up front from the soft lines forward(put longer YJ ones on).

My brother in law is currently doing both calipers on my yj after one froze up.

On the way to the shore. In Memorial Day weekend traffic.

I clamped it off and drove ~50 miles to his house Monday night without touching the brake pedal.

He said I managed to blow a rear piston too so I would've only had one front brake. Lol jeep.

Hubjeep said:

Don't plan to. There is nothing wrong with the other and it's only three years old, maybe if it was an older vehicle.

If anything, I prefer to leave as much brake hydraulics alone as possible to minimize leaks (I hate brake hydraulic fittings of any kind... flared, banjo, etc).

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Never had any fittings leak after servicing brakes.

Jays89YJ said:

Never had any fittings leak after servicing brakes.

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Perhaps I have lasting memories of a swiss-cheese rusted CJ-7 with a plow from about 15 years ago that I worked on... including many brake lines. Drip, drip... fawk!

Hubjeep said:

Perhaps I have lasting memories of a swiss-cheese rusted CJ-7 with a plow from about 15 years ago that I worked on... including many brake lines. Drip, drip... fawk!

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Are you doing the caliper swap on Monday? I've tried swapping one caliper at a time and the brakes never felt right until I replaced both. And when I replaced both, I replaced the rotors and pads as well. This was on a '99 WJ Ltd. in '02.

I've successfully replaced single calipers without issue. But if the other side is also slightly flaky, you might notice its issues more easily. I replaced one caliper on my car last year and no problems. I didn't want to do both due to not really wanting to spend the additional money.

themonk said:

I've successfully replaced single calipers without issue. But if the other side is also slightly flaky, you might notice its issues more easily. I replaced one caliper on my car last year and no problems. I didn't want to do both due to not really wanting to spend the additional money.

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My stepdad, who used to be a mechanic, advised replacing both sides at once and I didn't. He made sure to rub it in.

And I did the one on my car on the lift in my landlord's shop, he advised doing the opposite, only the one that's an issue.

Jays89YJ said:

Are you doing the caliper swap on Monday? I've tried swapping one caliper at a time and the brakes never felt right until I replaced both. And when I replaced both, I replaced the rotors and pads as well. This was on a '99 WJ Ltd. in '02.

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It will probably arrive on Wed.

Jays89YJ said:

My stepdad, who used to be a mechanic...

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Mechanics always say to replace both (also cut, replace rotors at every pad change, which is true you SHOULD for 100% pad contact from the start), it's the knee-jerk suggestion and by-the-book for brake repairs. In this case the one remaining should be just as good as new, if a much older vehicle I may do both.

Hubjeep said:

It will probably arrive on Wed.



Mechanics always say to replace both (also cut, replace rotors at every pad change, which is true you SHOULD for 100% pad contact from the start), it's the knee-jerk suggestion and by-the-book for brake repairs. In this case the one remaining should be just as good as new, if a much older vehicle I may do both.

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He's an oldschool mechanic, circa 1970s. He's not a mechanic anymore, but he did thoroughly enjoy he was correct.

I did both on the TJ cause they were $21 each.

Jays89YJ said:

He's an oldschool mechanic, circa 1970s. He's not a mechanic anymore, but he did thoroughly enjoy he was correct.

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I'm not a mechanic, and have replaced one at a time. Given the cost for most non-M3 vehicles, I'd probably tend to want to replace both at the same time these days. I did that with the TJ last time. Replaced both the calipers, rotors, and pads. Entirely new front brake system for less headaches down the road.

wct097 said:

I'm not a mechanic, and have replaced one at a time. Given the cost for most non-M3 vehicles, I'd probably tend to want to replace both at the same time these days. I did that with the TJ last time. Replaced both the calipers, rotors, and pads. Entirely new front brake system for less headaches down the road.

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I'd be even more inclined to replace both on an M3 if one went bad.

Jays89YJ said:

I'd be even more inclined to replace both on an M3 if one went bad.

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Agreed, but the cost on other vehicles makes it a no-brainer.