I did a brake job on my 03 S-Type last week and besides pads and rotors, installed new rebuilt rear calipers. Everything went great untill I had to bleed the system. 2 hours with a Motive pressure bleeder and finally got a clear flow without air bubbles. So now I start the engine, press the brake pedal and it goes to the floor??? OK, now I'll follow my usual credo - "if all else fails, read the instructions (manual)". I used to consider myself a bit of a whiz concerning brakes (I have a racecar) but this is something new. According to the manual, if you replace the rear calipers you have to install a new pad on the inside and remove the outside rear pad and jam a cloth between the caliper fingers and the rotor so as not to damage the rotor. Then bleed the brakes without the outside pad in place. When the bleeding job is complete, remove the caliper again and replace the outside pad - and Bob's yer uncle. Who knew!

 

Which brakes (or, which engine?)?

Did that work?