Below are some pictures of disassemled brake calipers from a 1998 crown victoria police interceptor



The front calipers on the left used phenolic pistons. The rear calipers on the right had steel caliper pistons that were chrome plated.





Take note of the square cut piston seals. These make a tight hydraulic seal between the piston and cast iron body of the caliper. They also twist as the piston is applied, and cause the caliper piston to retract some when the brake pedal inside the car is released. Click here to view a document with additional information about brake caliper piston seal rollback.







Here's one of the front brake calipers.



Getting the first piston out of the caliper was easy using a blow gun connected to an air compressor.

However, after popping out the first caliper piston, the second piston wouldn't come out due to a lack of air pressure behind it because popping the first piston created a massive air leak inside the caliper. So the first piston was partially reinserted and held stationary with a large screwdriver handle, and then the second piston popped out with some air pressure applied to the banjo bolt port.

Note that you don't need a huge air compressor to pop out the pistons, a little 5 gallon one used for air nailing will work for this job. Some people have also reported success popping the caliper pistons out using a bicycle tire pump too. If no tools are avaliable, another method to get the caliper pistons out is to pump the brake pedal inside the car a few times with the calipers still attached to the brake lines in the car.

I had tried using some pliers to pull the piston out, but this was not productive and mainly resulted in damage to the piston from where the pliers were gripping.



Take note of the bevelled edge in the casting where the square seal would normally be located on these low drag calipers. Click here to view a document about this topic.





The front right and front left calipers are nearly identical except for the location of the bleeder valve. A passenger's front brake caliper will install onto the driver's side of the car, and vise versa. But you won't be able to properly bleed the brakes due to air rising into an area that doesn't have a bleeder valve.





Here are the rear calipers



The bleeder screw came out clean from this caliper



But it snapped off on this caliper



This caliper has some heavy scaly rust on it, but this is not much of a concern as the caliper is contructed of thick cast iron. And loosing a little metal on the exterior to corrosion doesn't adversly it's operation.



1992 and later crown victoria rear brake calipers do not contain any parking brake hardware like you'll find on some other vehicles. Instead, the parking brake system in these cars has a minature set of shoes inside the rotor hat like you'd find on an older car with rear drum brakes.

In some brake parts catalogs, you will see crown victoria rear brake rotors listed with DIH abbreviation in the part description. This acronym stands for "Drum-In-Hat" and means that the rotor hat will have a finely machined surface inside to accept the minature parking brake shoes.













Here are the caliper dust boots



Here's a phenolic (plastic) caliper piston





On the bottom of the phenolic caliper piston where the brake pads contact is a metal ring. In the caliper piston manufacturing industry, this is referred to as a "capped" piston.



Here's a metal piston from one of the rear calipers.



The groove in the piston is to hold the dust boot. The rubber o-ring seal mounts inside the cast iron body of the caliper.







Here's the metal ring from the bottom of one of the phenolic caliper pistons. This ring was retained really well to the bottom of the piston and got really mangled when a hammer/chisel were used to remove it.







Here are the components that allow the rear caliper to float. Normally these components would be coated in dielectric grease to keep out moisture.















These are the metal inserts that are mounted in between the rear caliper bracket and the brake pads





Here are the copper crush washers, a couple banjo bolts, and a bleeder valve





Here you can see one end of the fluid feed passage on the banjo bolt



And the other end of the fluid feed hole on the banjo bolt





This bleeder was somewhat corroded, but it did come out of the caliper without breaking



This is the rubber cap which keeps debris out of the bleeder fluid passage. It's around 10 years old, and was ready to fall of due to age related rubber deterioration.



Prior to installation, this washer would be flat. But after installation it has some fluid sealing grooves cut into it from being crushed in between components.









Here are the rubber boots which seal out moisture from the front calipers floating mechanism.



Here are all 4 old brake hoses from the car. They retain the shape they were held in for the past several years even after being removed from the car.





Here's a banjo bolt with a couple crush washers on it





And a couple of the surfaces that the crush wahsers would get crushed against.





A marketing picture from Undercar Express about their rebuilt brake calipers:




Links:

http://www.undercarexpress.com
http://www.mpbrakes.com
http://www.brakequip.com
http://www.fedhillusa.com
http://www.eastwood.com
http://www.mastercool.com/pages/flaring_tools.html
http://www.carcraft.com/howto/50919
http://www.classictrucks.com/tech/0501cl_brake_line_basics