Calipers--Metal or Phenolic Pistons

[danrbarden]

Ok, so it's got 99,000 on the OD and the stock brakes are about done, time to rebuild the brakes. First Question I ask myself what are my current and future intentions. Well I don't ever plan on putting out more than 400 RWHP. O.k. then Premium rotors and pads, Stainless Steel Braided Brake Lines, and some premium quality remanufactured calipers.

This is what I found out, almost every single caliper remanufacturer uses Phenolic Pistons, not good. Hard plastic pistons will fail under extreme use.
There is a lot of discussions on the pro's and con's of metal versus phenolic pistons. Phenolic will fracture under extreme high speed emergency stops. phenolic is highly prone to sticking in the cylinder bore of the caliper, causing caliper to not fully release and drag on the rotor causing high heat and eventual rotor warpage etc.

I purchased my calipers from rock auto online. I got some high quality remanufactured calipers by Cardone Industries. $484.72 including $169.00 worth of refundable core charges and including $30.72 shipping. They come loaded with pads, although I will be using EBC redstuff Pads. These come with High Quality Stainless steel pistons, etc.
Front Left Caliper#16-4841
Front Right Caliper#16-4840
Rear Left Caliper#16-4850
Rear Right Caliper#16-4851
Front Right Bracket #14-1050
Front Left Bracket #14-1049

I also purchased EBC Slotted and Dimpled Rotors all around to match the redstuff pads. And with the help of MMnet, I acquired TCE Stainless Steel Brake lines. Can't wait to get it all put on.

I Love my Marauder:burnout:

Danny

[lji372]

Sounds like your homework is done. Niiiiice!

Congrats :beer:

[RF Overlord]

This is what I found out, almost every single caliper remanufacturer uses Phenolic Pistons, not good. Hard plastic pistons will fail under extreme use.
There is a lot of discussions on the pro's and con's of metal versus phenolic pistons. Phenolic will fracture under extreme high speed emergency stops. phenolic is highly prone to sticking in the cylinder bore of the caliper, causing caliper to not fully release and drag on the rotor causing high heat and eventual rotor warpage etc.I'm not going to say you didn't read what you read, but I think a lot of it is inaccurate. Raybestos uses phenolic pistons in their Police Series calipers, and I can't think of a more extreme use than police use. Also, metal pistons are subject to corrosion, which can cause the piston to stick in the bore, too, so I can't see that metal is the clear winner here.

[fastblackmerc]

I'm not going to say you didn't read what you read, but I think a lot of it is inaccurate. Raybestos uses phenolic pistons in their Police Series calipers, and I can't think of a more extreme use than police use. Also, metal pistons are subject to corrosion, which can cause the piston to stick in the bore, too, so I can't see that metal is the clear winner here.

I agree with Bob. Phenolic pistons have been in use for a long time.

What do you consider "extreme" use?

[Mr. Man]

Say Baub as far as police use I would wonder if police depts like NYC, LA and the like have a failure rate much higher on what the OP posted vs. say your avg local police dept that tends to sit and idle 95% of the time waiting for something.....anything to happen. Thus % wise the overall failure rate would be about the same as the average Joe's.

SS should work fine

[danrbarden]

I've worked in the Aircraft industry and Metal Injection as well as the Plastic Injection molding industry, nearly my whole life. I've personally rebuilt scores of hydraulic cylinders from itty bitty to bigger than a tree trunk in size. Every single one used metal pistons, why not phenolic, because they would shatter under the extreme tonnages that there used for.
If Phenolic's are so awesome why don't Racing calipers use them, i.e. TCE, BAER, and the sort. I hope this enlightens you, and metal pistons wouldn't corrode if you flushed the entire brake system regularly, once a year or when it just starts to turn a darker color, got to keep the moisture out, and fluid fresh. I flush my system every 4th oil change as a minimum. I'm not the smartest tool in the shed, but I've been turning wrenches on big equipment for over thirty five years, I thought I made a valuable point for others, so they also could make an informed decision. You can go really fast, but stopping is as important if not more so. Especially if your doing 140 mph and have to make a sudden stop like yesterday in a 4500 lb. Marauder. You know "Things in Motion, Tend to stay in Motion", unless you got great brakes. I like my brakes to always be in tippy top shape.

Danny

[danrbarden]

Sounds like your homework is done. Niiiiice!

Congrats :beer:

I did my best, and hope the info I provided helps others out.
And Thank You,
Danny

[RF Overlord]

I don't mean to impugn your credentials, nor did I say your point wasn't valid, I simply meant that on a 747 metal might be better, but on a street-driven car, I don't think it's that critical. After all, how many stories do you hear about shattered brake pistons?

[EMAS]

One advantage of phenolic pistons is that they lower brake fluid temps as they do not transfer near as much heat from the pad to the fluid. As mentioned they also won't corrode.

That said the police package cars used metal pistons and when I replace the calipers on my Panthers I've always went with the Police calipers to get the metal pistons.

As far as doing your homework I'd say you didn't really complete the assignment. If you would have you would have found you could get high quality steel piston'ed calipers from Napa for less than the Crapdone stuff and you would have had it the same or next day and would have saved shipping both directions. The trick is to order stuff for a 03 CV "with police package".

[RF Overlord]

I was going by what Raybestos says on their web site:

"New phenolic pistons (where OE is phenolic)" (www.raybestosbrakes.com/magnoliaPublic/home/products/advanced-technology-police-patrol-products/at-police-calipers.html)

I didn't pay attention to the piston composition when I installed them on Mary's car, so they could indeed be metal, if that's what comes as OE.

[nusbd]

the phenolic pistons resist heat transfer to the fluid under extreme use, but this usage requires more maintenance, the stainless pistons resist corrosion from old water impregnated fluid better then the chrome steel. which material is better is a matter of preference. my cv station wagons with the tow package came with phenolic and never had a problem and each now has in excess of 375 k miles with only replacement seals.
My P71's (97 and 98) have phenolic. Haven't had this apart on my project 300A so too soon to tell.

[fordmike65]

Never had any issues in the hundreds of police and livery Panthers I've serviced brakes on in the past 15yrs. There has to be a clear advantage in using phenolic pistons instead of steel in heavy-duty applications. Otherwise Ford wouldn't have gone through the trouble to design specific pistons/pads for these vehicles. I can honestly say the only time I have seen where phenolic pistons failed were on early to mid 90's F350's. I had a few that crumbled just under the piston steel inserts that contact the pad. Even then, no catastrophic failure. No major cracks or leaks were ever found. Just a slightly soft pedal that felt like a little air was in the brake lines.

[guspech750]

Hmmmm. Interesting battle of the minds here. Informative, yet entertaining.

I never knew about the plastic pistons.

Sent from The White House on taxpayers dimes.

DTR + 4.10's + Eaton swap = Wreeeeeeeeeeeeeeedom

[MyBlackBeasts]

I remember when OEM started using the plastic pistons. They were crap. We were replacing calipers left & right as they would sieze up. Customers would come in @ 25 or 30k with a frozen caliper, after confirming suspicion of craplastic piston caliper we would replace both calipers with remans that used SS pistons. Customer was now good for 100k+.

Since years of that experience I have only used SS piston remans for personal jobs. My $0.02

[danrbarden]

One advantage of phenolic pistons is that they lower brake fluid temps as they do not transfer near as much heat from the pad to the fluid. As mentioned they also won't corrode.

That said the police package cars used metal pistons and when I replace the calipers on my Panthers I've always went with the Police calipers to get the metal pistons.

As far as doing your homework I'd say you didn't really complete the assignment. If you would have you would have found you could get high quality steel piston'ed calipers from Napa for less than the Crapdone stuff and you would have had it the same or next day and would have saved shipping both directions. The trick is to order stuff for a 03 CV "with police package".

Should've went to NAPA, OOps, But got the cardone stuff in, they look pretty stout. Yes phenolics have there place, but not on my ride. And that's some good info to know, that 03 CV with a police package will work.

All in all, this is a good thread, a lot of good points from all involved, pro and con. Should help anyone else thinking of brake work choose whats best route for them. Personally I would love to put a set of willwoods on, but think they would be major overkill for my intended use and pocket book.

Danny

[danrbarden]

I don't mean to impugn your credentials, nor did I say your point wasn't valid, I simply meant that on a 747 metal might be better, but on a street-driven car, I don't think it's that critical. After all, how many stories do you hear about shattered brake pistons?

I didn't take it that way, it's o.k. to voice your opinion. Just been in my personal experience and personal taste to go with metal instead of phenolic. I had a car flip on the expressway because the left front wheel piston shattered under emergency braking. No one got hurt bad, surprising even to this day. For me Phenolic is a no go.

Danny

[Todd TCE]

Remember that there is a difference between "steel" pistons and the Stainless Steel pistons found in Wilwoods and many others. Stainless has a great heat rejection property in keeping heat out of the caliper body. Steel on the other hand does not and is often both plated (chipping) and prone to rust.

If I were to bank on why..I'd say long term durability against rust is the main reason for the phenolic piston. From personal experience they were found on SRT4s and numerous folks has chipping and cracking problems when used on the track- no hard failures that I recall but a lot of unhappy comments and ultimate bbk purchases due in part.

[RF Overlord]

Todd, thanks for your expert input. :up:

So you're saying that for track or other extreme use, metal (stainless) would be better, but for everyday street use and ease of maintenance, phenolic is fine?

[Todd TCE]

I won't call it 'expert' but rather that race calipers are build with ss pistons for a reason. For street use..I can't honestly say I'd take one over the other. I suspect the phenolic would be more durable in the salt belt.

[danrbarden]

Thanks Todd, your input made some very valid points for sure. I definitely respect your opinions, and am looking forward to installing your S.S. Brake lines. Wish I had the bones to get the TCE BBK's. I would not only stop a lot faster, but I bet there a lot lighter than the factory style calipers and rotors by a large margin, which would definitely lower the total sprung wheel weight and most definitely make the cars handling a lot better too. Not to mention some serious bragging rights.

Danny