i changed one caliper also brake pads each side have bled brakes several times removed all the air from brake system checked the brake system one hour later, still had air in it. brake pedal goes down to floor no brake at all . i bled brakes with pressure bleeder gunsons . no signs of leakes as i looked straight after the pressure bleed could this be caused by the abs modulator would apreciate any help to solve this difficult problem thanks

dave, April 2010

If you pushed the caliper piston back without opening the bleed nipple you may have flipped a seal in the ABS unit or master cylinder.
Blank off the pipe from the master cylinder then try the brake, if the pedal goes to the floor, the cylinder is faulty. If the pedal is solid, the problem is further down.
Vauxhall dealers use their Tech 2 diagnostics to activate the ABS modulator while bleeding, if you allowed a lot of air in to the system this may be your best option.

vaux, April 2010

try bleeding it normally with ignition on

peesian, April 2010