l have a 1.4 Citroen zx, and it has at the back drum brakes, but l am not satisfied with them. l was going to buy rear disk brakes from a citroen xsara or a 206 or saxo vts rallye etc, but someone told me that if l brake at hight speed the tail of the car it will run of an l will loose control. Finally they suggested me l have to choose a larger drum disk brakes from Peugeot Berlingo so l wo not loose control of my car when l brake in hight speed.
ps:my zx has not ABS

the zx was (like most citroens & peugeots) renound for the lug on the self adjusters falling off & leaking rear wheel cylinders. remove the drums & inspect the brakes. u will probably find that a new set of shoes cylinders & adjusters should help. if u intend to change the system to discs all round l would try for zx volcane as rear discs were fitted to most of them. u will also need to change the hubs as they r different, the wheel bearings, back plates & above all if it is not already fitted & working properly, u will have to fit a rear load compensator & change the brake pipes to fit.
hope this is of some use
good luck

what he said