Rear Brake Piston Pitting

[dtxscott]

I'm in the midst of rebuilding the stock Ate calipers on my '89 Targa. All the components look really good and have cleaned up nicely. However, the impression on one of the rear pistons seems really odd.

It seems too symmetrical to be rust pitting. Almost looks like a mfg defect or a latent defect from a repair.

Anybody seen this before?

[djpateman]

That looks like it was struck with the end of a bolt. It does appear to my eye to have a risk of fluid leaking if it sat on the seal; then you could lose braking action. I would try and find a replacement. It may work okay for a while if the pads were full thickness.

[Dpmulvan]

Host sells them

[dtxscott]

Originally Posted by djpateman

That looks like it was struck with the end of a bolt. It does appear to my eye to have a risk of fluid leaking if it sat on the seal; then you could lose braking action. I would try and find a replacement. It may work okay for a while if the pads were full thickness.

Thanks for the comments. It is a weird impression for sure and I did have some minor leaking on that caliper.

[dtxscott]

Originally Posted by Dpmulvan

Host sells them

I did see the 48mm front pistons. This is a 38mm rear and haven't found it. If you know where it is located, I'd be grateful for the pointer.

[Locker537]

Give PMB a call: https://www.pmbperformance.com/catalog.html

[dtxscott]

Originally Posted by Locker537

Give PMB a call: https://www.pmbperformance.com/catalog.html

Great suggestion. Looks like they have 38mm pistons

[dtxscott]

For completeness and accuracy.... The rear pistons are 42mm on the 84-89 Carreras. I mixed the sizes with the SCs. I didn't see the 42mm pistons on PMB's site

Here' is a link to the rear pistons at Sierra Madre: https://*********************.com/Rear-Brake-Caliper-Piston-42mm-911-84-89-p30549.html

The url is all one comprised of these words: Sierra Madre Collection