Chrysler RAM TRUCK 2500 1994 Service Manual page 225

6 - 66 DRUM BRAKES
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SECONDARY WHEEL
SCREW SHOE
ASSEMBLY
SPRING
J9405-19
Fig. 11 Brakeshoe Gompon
(2) Remove piston boots. Use plastic or wood tool
to either pry boots out or pull them out with needle-
nose pliers.
(3) Push pistons, cups and expander spring out one
end of cylinder bore (Fig. 12).
(4) Discard boots, piston cups and expander spring.
They are not reusable parts.
(5) Remove bleed screw from cylinder.
Wheel Cylinder Cleaning And Inspection
Clean the cylinder, pistons and links with Mopar
brake cleaner. Clean the wheel cylinder and support
plate mounting surfaces with a wire brush to ensure
proper seating at installation.
Inspect the cylinder bore. The bore should be
smooth and free of scoring, corrosion, or pitting.
Light discoloration of the bore is a normal condition
and does indicate replacement is necessary. Very
slight scratches, or nicks can be polished out by hand
with crocus cloth.
The cylinder bore can be cleaned out with a fiber
bristle brush i f necessary. However, D O NOT hone
the cylinder bore. Replace the wheel cylinder
as an assembly if the bore surface is corroded,
pitted or scored.
Check condition of the cylinder brakeline and bleed
screw threads. Replace the wheel cylinder i f the
Installation (13 Inch Brake)
threads are damaged i n any way. replace the bleed
screw if the screw threads are damaged, or the screw
is corroded, or distorted.
Inspect the wheel cylinder pistons. Replace the pis­
tons i f worn, scored, corroded, or pitted. Do not sand
the pistons i n an attempt to restore the surface and
reuse them. I n most cases, i f the pistons are dam­
aged, the cylinder bore will also be damaged requir­
ing complete replacement.
The wheel cylinder connecting links can be cleaned
up with a wire brush i f rusty, or corroded. However,
be sure the link notches are i n good condition and
will seat properly i n the brakeshoes.
Wheel Cylinder Assembly
(1) Install bleed screw i n cylinder. Finger tighten
cylinder only at this time.
(2) Coat cylinder bore, pistons and piston cups
with liberal quantity of fresh, clean brake fluid.
(3) Cylinder components can be installed two ways.
Either as an assembly (Fig. 13), or individually. Pro­
cedures are as follows:
(a) To install as assembly, assemble pistons, new
cups and expander spring as shown (Fig. 13). Start
one piston and cup into bore. Then slide expander
and remaining cup and piston into bore in one mo­
tion.