Hi All, I hope I can impose on your collective wisdom again and sorry for the long post... I have a new build (by me) 420R with uprated 4 pot front brakes. The 420R also comes standard with the uprated master cylinder. I am through IVA and on the road but am finding the brake pedal feel is not as solid as I remember from test drives, and the pedal doesn't return to the top of it's travel. I have 160 miles on the clock... so open to the fact that this will get better... however... I'm concerned that with the pedal not returning to the top of it's travel, after pressing the brakes, the brake lights will stay on. I've adjusted the brake-light switch as much as I dare so that the brakes only stay on occasionally now, but I'm worried that the brake lights will stay on and people following me don't appreciate that I'm braking again. I've had a couple of near misses already - or is this normal for people to rear-end a Caterham! The brake pedal drops about half of its full travel with a solid push, and feels spongy (in non-assisted brake terms). The tech at Williams reported that I probably had air in the system and bleeding them should get the pedal firmer and it should then return to the top position after pressing the pedal. But... I've now bled the brakes 5 times. I've used the tried and tested: undo nipple, press pedal, close nipple, pedal up, repeat. I also bought a pressurized brake bleed system as used by the tech at Williams. Have used the pressurized system 4 times now. The next piece of the puzzle is that the brake pedal feel is rock solid if the handbrake is slightly on. So, having read various posts (though still not sure quite why) I have also slackened off the handbrake, taken the rear calipers off and wound back in the pistons. As part of this process I tipped and banged the calipers endlessly in the hope that any air pockets would be dislodged. I then fitted the calipers and pumped the brakes to set the pistons and reset the handbrake... no change. My current theory is that for some reason the rear brake pads are coming too far off the discs when there's no pressure on the brake pedal... partially applying the handbrake will push the pads closer to the discs and pre-engage them for when the pedal is pressed - hence a firm pedal in that situation. Any suggestions gratefully received. I have the club Novices Trackday booked for end of April and clearly keen to make sure I have great brakes by the time I get there. Thanks in advance, John