Poor brake pressure after front hose replacement

[S6 Devil]

I have just had the front brake hoses replaced on my XJR8 with standard brakes (not Brembo) after it failed the MOT. The pedal now stops the car but isn't firm like it was before. On pumping the pedal it firms up. The garage are telling me that it could be the master cylinder. It sounds like air in the system to me. They have used about 5 litres of brake fluid and a pressure bleeder but it still isn't right.

I read a post that suggested unbolting the calipers and rotating them until the nipple is pointing directly up, then bleed. Any other ideas before I ask them to try a second hand master cylinder?

[S6 Devil]

Thanks all. Unbolting the calipers and rotating fixed it. 3 little bubbles emerged and all is well.