S caliper rebuild?

[jrblackbox]

I am thinking about rebuilding a pair of "S" aluminum calipers.
They appear to be in great shape, without any visible corrosion on the outside. I got the kits, but there isn't a retaining ring included for the rubber boot? what gives?

[deemsriddle]

Early S calipers are very porous and are hard to rebuild adequately. I have a rebuild kit at home taking up space and a pair of calipers at PMB in Utah awaiting return. Check out their website.

https://pmbperformance.com/

[jrblackbox]

I did check out PMB. My question is about the retaining ring for the "S" calipers. Here on Pelican the rebuild kit for the S does not include a retaining ring.

[deemsriddle]

My S Caliper rebuild kit is probably 25 years old.

[Dpmulvan]

Use the old one

[75 911s]

I don't think the retaining ring is included if I remember. I have two rebuild kits at the shop, I'll check for you later. Another thing that is NOT included is the inner cover O ring. That's your number one leak spot on an S caliper usually. Check the cap and make sure there aren't little voids and corrosion marks around the sealing edge or it will absolutely drip. PMB makes new S caliper caps and also their own O rings FYI.

[jrblackbox]

All the other caliper kits listed here on Pelican have the retaining ring included in the kit. It appears the only kit that doesn't is the kit for the S.