All I done with mine, Veek 1000, was fill the rad slowly till top, let it settle a bit, top up a few times then fit the cap, take the bike of the stand, sit on it and shake it about side to side for a few minutes, put it back on the mainstand, remove the cap and top it up, refit the rad cap and fill the expansion tank to the max. That way if it takes a wee bit from the tank you don't need to fill it as on the thou its a bugger to top up. Mine took 2 litres by the way.