Jeep 1987 Wrangler Workshop Manual page 985

BRAKE SYSTEM
< U 4 §
BRAKE SYSTEM SERVICE
84035A
Remove and discard seals (3) and (4) from the
secondary piston.
Remove the rear seal (6), spring (8) and retainer
(7) from the secondary piston. Discard the seal.
Inspect the outlet port tube seats (10). Replace
the seats if loose or damaged as follows:
# Enlarge the hole in the seats with a 5 mm
(13/64 in) drill bit.
# Place a flat washer on each outlet port and
thread a 1 /4 - 20 by three quarter inch long
screw into each tube seat.
# Tighten the screw until the seat is loose.
Then remove the screw and seat.
Clean the master cylinder with brake cleaning
fluid. Dry the cylinder with compressed air. Be
sure to remove any chips generated during tube
seat replacement. Replace the cylinder if the
bore is scored, corroded or pitted.
Coat the master cylinder bore, pistons and
seals with clean brake fluid.
Install replacement seals (3), (4) and (6) on the
secondary piston.
CAUTION: Be sure the lip of seal (3) faces for-
ward and the lip of seal (6) faces rearward.
Install the retainer (7) and spring (8) on the sec-
ondary piston and install the piston assembly in
the cylinder.
Install the replacement primary piston assembly
(2) and install the snap ring (1).
Bleed the master cylinder as follows:
• Mount the cylinder in a vise and fill the
reservoirs.
j Fabricate and install two bleed tubes (1) and
install them in the outlet ports.
• Slowly compress the pistons with a dowel
rod (2). Then allow the pistons to return
under normal spring pressure. Continue this
operation until air bubbles no longer appear
in the brake fluid.
• Press the replacement tube seats into the
outlet ports with a spare tube fitting.
K- 13