Symptom Driven Diagnostics.
Some say it also stands for System Driven Diagnostics.

 

Strange. I've done this several times on an XF 5.0 SC and never had to open any bleed nozzle. Just wound in the caliper and made the swap of pads.

 

Much the same here, I have changed the rear pads a few times across XFS, XFR and F-Type and all I have ever done is draw a bit of fluid out of the brake fluid reservoir to ensure it didn't overflow when I wound or pushed the pistons in. Each time I need not have bothered as the level in the reservoir hardly budged anyway which I put down as due to the "old" pads being not all that worn (maybe 1/2 worn max) so the pistons didn't need to go very far back in.

 

Did my rear pads on a 2014 XKR over the winter. Hardest part was ordering the correct pads. Even the dealer sold me the wrong pads. My XKR uses the same pads as the XKR-S. I used an Autel AP200 dongle to retract the pistons and put the calipers in service mode, and a manual adapter kit to completely scew in the pistons. There was no need to relief pressure through the bleed screw. However, one must unscrew the reservoir cap. I also was mindful of any overflow from the reservoir and never had to remove any fluid. Although, my pads were not severely worn. I reused the original sensor.

 

Not to state the obvious, but did you remove the cap on the master cylinder before winding calipers back? I usually suction out remaining fluid from the master cylinder as part of brake service and install new fluid on completion. Never had this issue.

 

Yes, I always do this. Master Cylinder Cap off and shop towel to collect any possible overflow. No removal of fluid though (until bleed)

On both the XKR and XJ, rear caliper wouldn't retract until the bleed screw is released.

 

The XFR workshop manual does not mention this as a part of the Brake Bleeding process. So I am assuming that it would not be needed.

 

Very well written, Adam! Thank you for taking the time!