So, I got a bleed kit for my arsed front brake and none of the blocks supplied with it actually fit in the space. Could it be that it no longer retracts properly? I am tempted to smash it to bits with a hammer.

Few pics below in case you guys can spot the problem from those.

You are indeed correct. It is none of those. Follow the instructions in the video on youtube and you'll see that it doesnt really matter.

Silly question i know but have you pushed the pistons back in?

Silly questions welcome. I've no idea what I'm doing. Yes, I tried shoving them back in as far as I could without resorting to the hammer.

open the reservoir cap then try, make sure you spin the lever so that is level
edit: use the old pads in place to push them back

http://www.youtube.com/watch?v=GzZkEIrCBJ0 watch this.

Hmmm – I shall go and see what I can do. Thanks, folks.

I could never get any of them to fit either. Ended up using a tyre lever or something I think. Bleeding Avids is a faff.

Well, I've got a sort of working front brake now which is a big improvement. It's not awesome but maybe the new pads need to bed in a bit.

The 3rd one along should work/fit. The 2nd one along seemed have the pistons too far apart as the resultant bleed pulled straight to the bar

One on the left is for Elixor – the wedge shape goes in from the top to protect the pads when wheels are out, the flat top is used when bleeding after having pushed the pistons back.

I would have thought the two in the middle of the picture, marked 'Juicy Bleed Block' would be the ones but obviously not.

The one on the left seemed the closest to a fit out of the lot. I think they all say "Juicy Bleed Block" but the other two must be printed on the down-side.

Probably needs a trip to the mechanic but who's got time for that.

Pretty sure when I bled my Juicy's I used a block that looked like the middle two in your image. It just pushed in from the bottom and I think the groove in the block, cleared the blob on the piston…..

The one on the right is for the four-pot Codes.

I think I've used one of the regular 'Juicy Bleed blocks' (the middle 2) for Juicy 3s. I've since ground down one of the Juicy spacers to use for bleeding my Formulas…

As seanodav says, open the lever bleed screw and you will find the piston will move back. You probably last bled them with the worn pads in place so there will be slightly too much fluid in the system. Its a good idea to make sure that both pistons a freemoving at this point. Clean them and get them to move a few times holding one piston in first and then the other. Dont let them come all the way out or you will have to split the caliper. Welcome to the fun world of "juicy".