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Discussion Starter #1
What's with these things, seems to be fairly common that they drag, won't release all the way, or just plain get stuck. There's several threads on here of people having the same issue. Is the piston coating failing causing the phenolic to swell, or something else?
I've got them on two of my cars, and noticed how they both drag on one, so checked the other car, and found one drags, the other I can spin the wheel and it rotates a couple more times before it stops. With a beam style torque wrench on a lug nut it takes 12-15 foot pounds of torque to turn the rotor. I pulled the caliper, and blew air into the banjo bolt fitting and only piston came out, the other is stuck. I can rotate it, but that's all, can't get it to move otherwise, except to compress it with a c-clamp. Looks like I'll be going back to the cast iron 94-98 calipers.
 

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Yes, it's common with the 99-04 calipers, especially if the car sits for any period of time. Only recourse it to keep swapping out the calipers when they stick and hope you get a "good" one, or swap to a different caliper/brake setup.
 

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Discussion Starter #3
Right, that's what I'm doing. Went with these because two pistons is more better, and it's aluminum, so they were lighter. The first pair i got were from the junkyard, but after having issues with those hanging up I got new, or reman'd from either a chain store, or rockauto, and still have that issue.
 

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Rebuild them. They are cheap to rebuild. Buy new pistons. I have been looking around but do not see any other option for the pistons, they are Phenolic and have a tendency to bind in the bores. I would like to see stainless option or steel option but thus far have not seen any. Very common for PBR dual piston calipers to stick. If I still had my lathe, I'd spin a few pistons out and try them.
 

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Discussion Starter #5
Where are you getting new steel pistons for these?
 

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Where are you getting new steel pistons for these?
If you're willing to spend some money, a machine shop should be able to turn some out, for maybe a few hundred. It's not a terribly difficult piece to make up, just you don't get economy of scale for just 4 pistons.
 

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Discussion Starter #7 (Edited)
If you're willing to spend some money, a machine shop should be able to turn some out, for maybe a few hundred. It's not a terribly difficult piece to make up, just you don't get economy of scale for just 4 pistons.
Yeah, that's why I was asking. I sent the link to this thread to Jack Higley, seeing if they might want to try making some for the mustang market. Typically folks they deal with opt for the cobra brakes though.

Jack Hidley answered my PM, looks like there are steel already available, don't know if anyone tried these yet, but like he said, it's probably cheaper to just put cobra brakes on the front because they're proven.

 

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Discussion Starter #8
So of the 4 pistons in my 2 front calipers that came out easily with air pressure, they measured 44.9MM, the two that had to be pounded out, one through the banjo bolt hole, the other through a hole I drilled in the caliper body behind the piston, they measured 45.1 and and 45.2MM respectively.
 
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