Brake troubles - yota

yo on my old school yota im ran in to a bit of brake trouble, i bought it as a half done project well ive pretty much done it now i need to go for road worthy inspection (we call it pink slip) anyways under a bit of pedal pressure the rears lock up, can i adjust this or is it just cos the fronts are worn, tho i took them off to replace them yesturday (tools at the shop sold me the wrong ones) and comparing the new ones and the existing it looked about half way down, nothing like down to metal.its on a 82 toyota.thanks.