Chrysler RAM TRUCK 2500 1994 Service Manual page 171

5 - 12 MASTER CYLINDER •
CYLINDER
BODY
SECONDARY
PISTON
SPRING
SECONDARY
PISTON AND
SEALS
PRIMARY PISTON,
SPRING AND
SEAL ASSEMBLY
SNAP
RING
J9405-10
Fig. 12 Master Cylinder Piston Removal
(10) Disassemble secondary piston (unlike primary
piston, secondary piston components are serviceable).
Remove seal retainer from secondary piston. Then re­
move front and rear seals seal from piston (Fig. 13).
Discard seals, spring and retainer after removal.
These parts are not reusable.
SPRING
REAR S E A L
FRONT
S E A L
RETAINER
PISTON
J9405-11
Fig. 13 Secondary Piston Components
MASTER CYLINDER CLEANING AND INSPECTION
Clean the cylinder body and reservoir with Mopar
brake cleaner only. Do not use any other type of
cleaning solvent especially on the plastic reservoir.
Dry the cylinder parts with compressed air. The res­
ervoir can be air dried or wiped dry with lint-free
shop towels.
Inspect the cylinder bore. A light discoloration of
the bore surface is normal and acceptable. However,
replace the cylinder body i f the bore is scored, pitted,
or corroded.
Inspect the cylinder cover and diaphragm seal. Re­
place the seal i f torn, or distorted. Replace the cover
if warped, cracked, or the snap fasteners are dam­
aged.
Inspect the reservoir. A slight discoloration of the
reservoir surface is normal. Replace the reservoir i f
distorted, cracked, or damaged i n any way.
Inspect the take up valve i n the cylinder body. The
valve should move freely and not be stuck or seized.
The valve is not serviceable. I t will be necessary to
replace the cylinder body i f the valve is faulty.
Inspect condition of the secondary piston. Replace
the piston i f i t is scored, corroded, or doubt exists
about its condition.
MASTER CYLINDER REASSEMBLY
(1) Coat cylinder body bore, piston components and
reservoir grommets with fresh, clean brake fluid.
(2) Mount cylinder body i n vise. Clamp one cylin­
der mounting ear i n vise jaws.
(3) Assemble secondary piston components (Fig.
13) . Be careful when installing seals. Avoid distorting
them during installation.
CAUTION: Do not use any kind of metal tool to e a s e
piston seal installation in the cylinder bore. Metal
tools will cut the seals and scratch the bore. If a
tool is needed, u s e a small flexible item made from
nylon, rubber or plastic only.
(4) Install secondary piston assembly (spring end
first), i n cylinder bore. Do not force piston into
bore. Work it into place with a twisting/turning
motion.
(5) Install primary piston i n cylinder bore (spring
end first). Do not force piston into bore. Work it
into place with a twisting/turning motion.
(6) Insert piston retaining snap ring i n cylinder
body. Then push pistons inward with wood dowel and
seat snap ring.
CAUTION: B e very sure the piston retaining snap
ring is fully seated. Recheck snap ring installation
before proceeding.
(7) Install new grommets on cylinder body (Fig.
14) .
(8) Remove cylinder body from vise.
(9) Position reservoir on clean Work surface with
fluid inlet necks facing upward (Fig. 14). Padding
work surface with clean shop towels will keep reser­
voir i n place during installation. I t will also keep dirt
out as well.