Conventional drum brakes.
Disc brakes may have been an option but it would normally come stock with drum brakes.
A 1991 mercury topaz has drum brakes on the rear wheels.
front disc, rear drum.
disk It has both.
( 1 ) on each of the rear drum brakes
My 98 LS has 4 wheel disc brakes. I would not be surprised though if some have drum type brakes in the back - maybe dependent on which motor the vehicle has.
What about 1993 Pontiac drum brakes, please be specific.
Drum brakes.
This will greatly depend on what kind of brakes you have and which parts you are trying to replace. Do you have disc or drum brakes? If you have disc brakes, do you want to replace the calipers, pads, or rotors? If you have drum brakes, do you want to replace the drum, or the shoes?
The rear brakes are a conventional drum system. If you don't have experience working one them I suggest buying a repair manual or taking it to a shop.
No. Drum brakes expand inside a rotating drum to stop the vehicle, disc brakes squeeze in against a rotating disc.