Brake Calipers "Phenolic or metal piston"

[jeepboy381]

I am looking at brake calipers online and it looks like they have two choices. I though all calipers had steel pistons but it seems for cheaper I could get Phenolic pistons instead in the caliper. I am not sure what Phenolic means but from what I can hear the piston will not rust. Which is the better option? Having a piston that wont rust is great because if you ever have to push the piston back down for new thicker pads and rotors there won't be any rough surface to cause the caliper to stick. Which one will wear out quicker though? Thanks Josh

[5-90]

"Phenolic" is a variety of plastic. Phenolic has been used to reduce heat transfer into the brake fluid (which should not be a problem, if you stay on top of bleeding and changes,) but metal pistons will transfer heat away from the brake pad to help prevent "fade."

Phenolic, as you also pointed out, does not rust - and is rather cheaper to manufacture than metal (less energy to reach final form.)

I tend to prefer metal pistons, and I will pay extra for them - but I'm a little more "maintenance-minded" than most people who seem to just know where to put the key and fuel in. I think phenolic pistons weren't introduced so much to cut costs, but because people weren't doing their regular maintenance - and it was telling on them.

Considering most of us here are more maintenance-oriented than the average driver, I don't feel bad about suggesting that metal pistons be installed, vice phenolic.

5-90

[90XJay]

how much cheaper are they? mine only cost me $15 at my local car quest and that's for the metal ones. How much cheaper are the plastic ones? I would rather through in the metal ones myself

[1986Comanche]

I would go with the calipers with the metal pistons also. I just think they would hold up a lot better than the plastic pistons.

[Frank Z]

The WJ calipers I used on my heep came with phenolic pistons, but there is a metal ring where the pistons contacts the pad. I'm fairly certain most, if not all, phenolic pistons are built the same way.

[jeepboy381]

I wen't with the Phenolic pistons because that was all they had in stock there. The price difference between the few was minimal, I think under 5 dollars. The guy at the parts counter was quite knowledgeable and he said as long as it's not a race car you will be fine, that was not my deciding factor though. My older steel piston calipers failed on me due to corrosion, they were extended out really far because my pads and rotors were getting thin. The outer edge of the pistons were corroded and when I pushed them back in to fit the new pads and slotted rotors, that corroded spot caused my brakes to drag like crazy. I had to stop 3 times on my way home so I didn't burn up my brakes and wheel bearings. I will tell you what though, I put carbon mettalic pads on and slotted rotors and I am extremely surprised that they did not warp. I know I shouldnt have driven with the calipers locked up but I had to get home somehow.