Phenolic or Metal caliper piston?

Posted by: BDW

Phenolic or Metal caliper piston? - 03/07/18 05:25 PM

I see rebuilt brake calipers listed with Phenolic or metal pistons.
No real difference in price, so which is better?
Phenolic Is ceramic/plastic based, so no rust issues.
Metal might be stronger with less deflection?

Which would you choose?

Thx
Posted by: jcastle1

Re: Phenolic or Metal caliper piston? - 03/07/18 05:29 PM

it does not matter, just make sure the pair are the same
Posted by: Andrewh

Re: Phenolic or Metal caliper piston? - 03/07/18 06:37 PM

there was an issue at one point for the phenolic ones so I always go metal.

they recalled them because it would cause the caliper to lock up and keep the brakes on till they cooled.
had it happen with an 84 new yorker. mbody car.
Posted by: therocks

Re: Phenolic or Metal caliper piston? - 03/07/18 08:05 PM

I agree had problems with Phonelics sometimes.I use metal.Rocky
Posted by: jcc

Re: Phenolic or Metal caliper piston? - 03/08/18 12:58 PM

"Phenolic Is ceramic/plastic based, so no rust issues."

Are we talking 70's stuff, never heard the ceramic description before.
Not sure rust is that much of a problem anyway if using a CI caliper.

I suspect phenolic was a cheaper solution, I would chose alum between the two. twocents
Posted by: dogdays

Re: Phenolic or Metal caliper piston? - 03/08/18 01:46 PM

Phenolic....."a usually thermosetting resin or plastic made by condensation of a phenol with an aldehyde and used especially for molding and insulating and in coatings and adhesives — called also phenolic resin."

There are no ceramics in phenolic.

On the first Ford Tauruses, the standard cars got phenolic caliper pistons, the cop and taxi and SHO models got metal pistons. So in that case metal pistons were more high performance.

Regarding thermal linear expansion, phenolic is 6 times the expansion of steel, 4 times the expansion of stainless steel, and 3 times the expansion of aluminum. Numbers were rounded.

So phenolic expands more per degree increase than three common metals.

Go with the metal pistons.

R.
Posted by: horsepower.2007

Re: Phenolic or Metal caliper piston? - 03/08/18 03:41 PM

I had phenolic calipers on my lil red, They stuck all the time.