On 1996-2002 ford crown victorias you will get asked by your parts
consultant whether you have a phenolic or metal pistons in the rear
calipers when you attempt to order rear brake pads. To determine which
type of caliper you have in your particular car, you are going to have
to remove one of the rear calipers from your car and physically inspect
the piston.
Here is a crownvic with a phenolic rear brake caliper piston
Here is a crownvic with a metal rear brake caliper piston
Here are two inner brake pads.
On the top is a rear inner brake pad for a crownvic with a phenolic
rear caliper piston (1.00" rosebud clip diameter)
On the bottom is a rear inner brake pad for a crownvic with a metal
rear caliper piston (1.75" rosebud clip diameter)
Although not shown, the outer brake pad is the same on cars with
phenolic caliper pistons and with metal caliper pistons.
There is no rhyme nor reason to which vehicles ford used phenolic rear
caliper pistons on and which vehicles ford use steel pistons on. Some
civilian cars got metal rear caliper pistons while other civilian cars
got phenolic rear caliper pistons. Some police cars got metal rear
caliper pistons while other police cars got phenolic rear caliper
pistons.
If you are replacing the rear calipers on your car with a set of
remanufactured "loaded calipers" that come with new brake pads
included, you can use either phenolic calipers or metal calipers in the
rear. The brake flex hoses are the same between the two calipers, as
are the rotors,
the sliding hardware, and the caliper mounting points. Do be aware that
you will need the appropriate banjo bolt for the caliper of your
choosing. Most remanufactured phenolic rear calipers will need an
M10x1.0 "fine thread" banjo bolt while most remanufactured metal piston
rear calipers will need an M10x1.5 "coarse thread" banjo bolt. You will
sometimes see calipers with phenolic pistons referred to as "heavy
duty".
Also, starting in the 2003 model year, all panther plaform vehicles
(ford crown victorias, mercury grand marquises, and lincoln towncars)
recieved metal rear caliper pistons. So there are no worries about
getting the wrong type of rear brake pad for your particular car in the
2003+ vehicles.