Rear brakes and hand brake are self adjusting. The adjusters are not very effective. Try pressing the footbrake hard and holding it down. WHile doing this pull the hand brake on as hard as possible and release several times. Release the footbrake and then repeat the process half a dozen times, It always works for me. If you tighten the cable you will only have to release it again when you change the rear pads or they wont fit. If the cables are stretched change them but beware non Fiat cables are generally crap. Not as strong / thick and also many a very poor fit in general. The extra cost of genuine parts is worth it. Excess cable wrecked a new tyre on mine in 100 miles with a Borg and Beck cable that was a very poor fit. Changed back to Fiat parts and no problems again.