I’ve found a few references but no mention if need to remove brake fluid reservoir cap prior to compressing the brake pistons like most other cars/trucks?

Also, any good DIY write ups out there that I may missed?

No doubt 958 CTT front brakes are different than non-turbo and 957 CTT.

 

Anyone?

 

If you’re compressing the pistons and the cap is not off, you’re working against pressure in the reservoir. So remove the cap and then some fluid to avoid an overflow. Same process I’ve used for my 991.1 and Panamera.

 

Good to go. I removed some fluid from the reservoir so when I compressed the piston no spillage. Decided to replace pads and rotors and flush the system 👍