Rusty pistons tearing rubber seals when you pushed them back in and letting air in.

Bleed them...

Did you crack open the bleed valves when you pushed back in the pistons? If not, you may have damaged the master cylinder seals.. same cause..

Can take around 200 miles to fully bed new pads and discs in, you did put new pads on too i assume, no offence but some don't.

Ah you didn't change the pads, that's why it's taking so long to bed in then.

The pads will have worn with grooves in them, possibly quite a sizeable extra width at the edge where rust makes the old disc thinner, and the inside edge possibly thinner at the dge of disc wear.

You have to wear through this extra meat with effectively maybe only 15 to 50% of braking surface in contact with the new disc till it gradually wears and you get full contact.

Could be a thousand miles or more if the ridges are bad, the softeness you feel is effectively fade as the small contact area of the pad is getting very hot during braking.

You should really put new pads in whenever you change discs.

If you don't want to buy new pads, you could try rubbing all odd wear away on coa-rse sandpaper laid flat on a smooth surface, meself i'd nip down to a good motor factor and get quality make new pads.

Edited by gordonbennet on 30/07/2011 at 14:49