Argggggh!!
All reassembled to discover when the handbrake is on, there is slack in the new shoes as they take up the slack.
On closer inspection the new shoes are 2-3mm shorter which means they do not rest on the handbrake bracket, hence with the handbrake on, you can rock the wheel back and forward a degree or 2.
Taking measurements I’ve also discovered the brake material is thinner than the ones being removed by nearly 2mm. They will be going back, and I either refit the originals, or get new ones from BMW.
Very disappointed as I got Jurid same as the OE, and wasted a good few hours.
To add insult in the process I pressed the brake pedal and popped the pistons out of the rear callipers, and can’t get them to go back in, so have decided to remove them and get them refurbished, and at the same time fit a new brake flexi hose given the corrosion.

