- Drain the remaining fluid from the caliper.
- Carefully remove the dust boot from around the piston by prying the boot
ring out of its groove. Remove the piston and piston boot by applying compressed
air through the brake hose fitting hole.
CAUTION
Do not hold the caliper during this procedure, and do not place fingers
in front of the piston in an attempt to catch it or protect it when applying
compressed air. Place a piece of cloth in front of the piston, and slowly
increase the force of the compressed air to prevent the piston from springing
out abruptly; use just enough air pressure to ease the piston out.
- Remove the seal from the inside of the caliper bore. Clean the caliper bore
with brake cleaner, alcohol or brake fluid.
WARNING
Never use a screwdriver or similar tools, because doing so could damage
the cylinder surface.
- Check all the parts for wear, deterioration, cracking or other abnormal
conditions. Corrosion, generally caused by water in the system, will appear
as white deposits on the metal, similar to what may be found on an old aluminum
storm door around the house. Pay close attention to the condition of the inside
of the caliper bore and the outside of the piston. Any sign of corrosion or
scoring requires new parts; do not attempt to clean or resurface either face
if there is damage present.
- The caliper overhaul kit will, at the minimum, contain new seals and dust
boots. A good kit will contain a new piston as well, but you may have to buy
the piston separately. Any time the caliper is disassembled, a new piston
is highly recommended in addition to the seals.
- Clean all the components to be reused with a brake cleaner, alcohol or clean
brake fluid and dry them thoroughly. Take any steps necessary to eliminate
moisture or water vapor from the parts.
- Coat all the caliper components with fresh brake fluid from an unopened
can.
NOTE: Some kits come with special assembly lubricants for
the piston seals and slides or guidepins. Use these lubricants according
to the directions within the kit.
- Install the piston seal and piston into the caliper bore. This is an exacting
job; the clearances are very small. Make sure the seal is seated in its groove
and that the piston is not cocked when inserted into the bore.
- Install the new dust boot and new boot ring.
- Install the slide bushings and rubber boots onto the caliper if they were
removed during disassembly.
- The guide and lockpin sleeves should be coated inside with the grease supplied
with the rebuilding kit, and boots should all be replaced. Also coat the lips
of the boots and the surface of the caliper which bears (and turns) against
the caliper support with grease.
NOTE: Two kinds of grease may be packed in a rebuilding
kit; use the grease recommended for use with the guide and lockpins. On
all the truck systems, coat the sliding parts of the caliper body and the
sleeves with the grease specified.
- Install the brake caliper to the wheel assembly.
