Have just been trying to lubricate a couple of pistons on my Code 5's and one of the pistons popped out of it's hole 😳 – pushed it back in no probs but there brake lever just goes all the way to the bar now without the pistons moving. Have i introduced air into the system and it's bleed time or could I have done other damage when the piston popped out?

yes you have gotten air in the system , you need to bleed.

Thanks Knottie – what a dick! (me not you) 🙁

yup AIR is your enemy 🙂