Steel vs Phenolic Piston

Status
Not open for further replies.
Joined
Sep 14, 2015
Messages
861
Location
NE Ohio
I think I already know the answer to this but here goes.

My neighbor asked for my help on replacing the rear (disc) brakes on his 2001 Lincoln Town Car. I took a quick glance at it to confirm that they were discs. I noticed that the rotors were pretty worn. Money is tight for them but I probably would've urged them to do new rotors either way. I found that Rockauto has a Power Stop kit (rotors, pads and slide pins) for about $75, this looks like a good fit but it makes a distinction between Steel and Phenolic caliper pistons.

Is there any chance in the world that there's any way to determine steel or phenolic pistons besides disassembling the whole thing?
 
I'm not replacing the calipers.

They list two different pad/rotor kits based on whether you have Steel or Phenolic caliper pistons.
 
There's something different about the back of the pads depending on whether the caliper piston is phenolic or steel. You might have to pull one caliper to take a peak. But before doing that, PM Trav.
 
Its how the inner pad clips to the caliper piston.Get the wrong one and the pad wont fit.
 
Originally Posted By: NHGUY
It's how the inner pad clips to the caliper piston. Get the wrong one and the pad won't fit.


Interesting. I learned something on BITOG today.
55.gif
 
Yes, you need to confirm the piston type - or else the pads may not fit.

For a good "budget" brake kit, get Centric 105 posiquiet ceramic pads with their 120 series premium rotors. Both are quite inexpensive on rockauto and are a much better product than powerstop.
 
Cruising a couple of OEM Lincoln parts websites it appears Ford/Lincoln only list one set of rear pads for a 2001 Town Car. My guess would be that there is an actual year/VIN changeover and the aftermarket suppliers just specify the difference in calipers VS the year VIN changeover.

Lot can happen since 2001 though, so what it left the factory with isn’t a guarantee that is what is present now.

Incidentally - OEM parts are not what I would call expensive.
 
How much is shipping on rotors?

Seems like this might be best at a local parts store. I.E. buy both sets of pads and one set of rotors.

Return the unused pads.

You take it apart ONCE

You don't pay to ship two pretty large iron rotors.

You know you have the right pads because you bought both and only used the ones you need.
 
Originally Posted By: turtlevette
Just go with phenolic. Doesn't transfer heat to the brake fluid.



How does that happen?. Might take longer for the piston to get hot, but also longer to cool down again.

Claud.
 
Originally Posted By: Claud
Originally Posted By: turtlevette
Just go with phenolic. Doesn't transfer heat to the brake fluid.



How does that happen?. Might take longer for the piston to get hot, but also longer to cool down again.

Claud.

The plastic just doesn't transfer heat fast and probably has a pretty low thermal energy storage capacity compared to most metal. Just like wood.
 
Originally Posted By: IndyIan
Originally Posted By: Claud
Originally Posted By: turtlevette
Just go with phenolic. Doesn't transfer heat to the brake fluid.



How does that happen?. Might take longer for the piston to get hot, but also longer to cool down again.

Claud.

The plastic just doesn't transfer heat fast and probably has a pretty low thermal energy storage capacity compared to most metal. Just like wood.


Until the phenolic one disintegrates from heat.
 
For the OPs sake I did a lot of searching and reading on phenolic vs steel brake caliper pistons, and wasn't able to come to a good conclusion other than knowing that phenolic pistons are cheaper to produce.
 
Originally Posted By: mightymousetech
Originally Posted By: IndyIan
Originally Posted By: Claud
Originally Posted By: turtlevette
Just go with phenolic. Doesn't transfer heat to the brake fluid.



How does that happen?. Might take longer for the piston to get hot, but also longer to cool down again.

Claud.

The plastic just doesn't transfer heat fast and probably has a pretty low thermal energy storage capacity compared to most metal. Just like wood.


Until the phenolic one disintegrates from heat.

Do they ever fail in normal use? I had an early 95 Neon with front brakes that fit in 13" rims which had phenolic pistons. I just put some KVR pads on it and it didn't brake fade on the DDT going clockwise in 20 minute sessions, even running r comps. I only ended up doing a few track days on the car, so maybe the pistons days were numbered? I did have to run the heater to keep from overheating so I wasn't taking it easy either!
 
USUALLY, and I say usually because these are mass produced cars and anything can happen where they are going down the assembly line, the Civilian cars got the steel piston and the Police cars got the phenolic.
If you want to be safe, buy ones for steel piston locally and you can easily return them if they are wrong.
 
The rotors appear to be original (clips still on) and are badly grooved. I didn't want to risk it not going back together right while waiting for parts. I got lucky and could look at the piston through the 'inspection hole' in the caliper after the wheel was off.

They are, indeed steel pistons. Parts are ordered. Thanks everyone.
 
Status
Not open for further replies.
Back
Top