Hi everyone,

While doing my caliper overhaul on my 02' C4S I damaged one of the 30mm rear piston...
It slip from my hand and felt on the floor...
What are my options?
Ive seen single piston for sale on RockAuto from Centric brand.
Dont know what to do as this part is not available from Porsche.
By chance is there a Brembo part number and a place I can order it online?

Here's a picture of the damage:


I guess I just cant file down this little recess and re-install?

 

I wouldn't, brakes are not something to monkey with!

 

I had to replace my front calipers pistons because the dampers were stuck in them and I couldn't get them out. I went with stainless pistons from Racing Brake and have been very happy with them. Because they're stainless, they are able to have thinner side walls and thus the factory dampers don't fit. So if you go that route, you basically don't run the dampers. I haven't noticed any ill effects or differences to be honest.

Also, I checked at the time and there is no part available from Porsche for just the pistons. You have to buy the entire caliper.

 

Okay

I want to correct my post as the reference number I had was not the good one..
I will have to do a little bit more research...
Anyone have feeback on the Centric piston?

 

Maybe give these guys a call:
https://www.zeckhausen.com/catalog/index.php?cPath=82

 

Thank you sir I will do that first thing tommorrow morning.

 

Hi

SS pistons would be my last resort..
I have no plan to track the car and I have to admit their kit are quite expensive compared to aluminum
piston.
I probably wont see the benefits of the SS pistons.
If something like a Centric piston can do it I will probably go for it.
A better option would be an OEM Brembo obviously..

 

Does the “square “ o ring even contact that area off the piston?

 

It seems that this part is touching the outer edge of the inner seal.


I used a file to smooth out the material, removed the seal from the caliper and tested with the piston in.
It doesnt seems to catch anywhere and I think I could re-use it if I could'nt source a part but I will try as much as I can before rebuilding my brand new caliper with this piston...
Too bad that most pistons are available except the one for the 996...

 

Alright guys!
I had a confirmation that I can re-use the piston without any problem.
I used a file to smooth down the bumps to make sure they wont slice into the dust boot.
What I understand is It's critical that any portion of a piston, that moves back and forth across the rubber pressure seal, be perfectly smooth. But damage to any other location on the piston is merely cosmetic and wont cause any problem.
As this section is past the pressure seal I am good to go.

 

I did just replace 2 of my smaller pistons in the front with centric. They were a little hard to source (had 2 or 3 orders canceled) but got them eventually. Product seems near oem, no issues with dampers.

 

IMHO,,, The cleanup will be fine, the only purpose the rear half of the piston has is to keep everything square.
Its not a precision fit, I've seen brand new pistons with more issues. Did you take a pic after filing ??

After you re-assemble just check them occasionally (It needs done anyway) Just look for any sign of fluid
around the seal. Hydraulics tend to leak or not,, not usually anything in-between.. Nothing finds a way out like 2200 PSI..

 

Hi

They are still not installed as Im waiting for an AS hard line rear driver side.
I destroyed it while changing the flexible lines.
I didnt install this piston yet as I have time to order a Centric piston.
When I receive it I will take mesurements (Im a machinist and have all the right tools) if the dimensions are within tolerance I will use the new one if not I will put back the "damged" one.

 

If you're a machinist, make a new one. I wish I had those skills!

 

Hi

I should have said I was...
Im now working in an office but back in the days I was a machinist.
Unfortunatly now I dont have access to a lathe and milling, one day I absolutely want both.
I still have all the mesurements tools.