c5 rear wont rise

[morto]

hello all ive got a c5 2002 plate it went in for the mot and the guy raised it to full the front came back downpk but the rear would not rise and stayed on the floor, on further examination the drivers side rear suspension boot was leaking so i put a new unit on ,, started car front goes up and down but the rear still nmot comming up any help,, could anyone tell me were the front body height sensor is i understand there the same for back and front so i cud change them over to see if it is that