Chrysler RAM TRUCK 2500 1994 Service Manual page 192

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REAR WHEEL ANTILOCK BRAKE (RWAL) SYSTEM 6 - 33
Fig. 19 Sensor Rear Harness Attachment
(5) Close bleed screws when fluid starts flowing
from each bleed screw.
(6) Top off master cylinder reservoir again.
(7) Bleed brakes i n following sequence:
• master cylinder
• combination valve
• rear antilock valve
• right rear wheel
• left rear wheel
• right front wheel
• left front wheel
(8) Observe following precautions during bleeding
procedure:
• Do not pump brake pedal at any time while bleed­
ing. Air in system will be compressed into small bub­
bles that are distributed throughout hydraulic
system. This will make a second and third bleeding
operation necessary.
• Bleed only one valve, or wheel brake unit at a
time and use a bleed hose on each wheel cylinder
and caliper bleed screw.
• Attach one end of bleed hose to bleed screw and
insert opposite end i n glass container partially filled
with brake fluid (Fig. 20). Glass container makes i t
easier to see air bubbles as they exit the bleed hose.
• Be sure end of bleed hose is immersed i n fluid. Im­
mersing hose end i n fluid prevents air from being
drawn back into cylinder and brakeline.
(9) Bleed master cylinder first. Have helper oper­
ate brake pedal while bleeding each master cylinder
fluid outlet line.
CAUTION: Do not allow the master cylinder to run
out of fluid during bleed operations. An empty cyl­
inder will allow additional air to be drawn into the
system. Check the cylinder fluid level frequently
and add fluid a s needed.
J8905-18
Fig. 20 Typical Fluid Container And Bleed Hose
(10) Bleed combination valve next and rear brake
antilock valve afterward. Bleed valves at brakeline
fittings one at a time. Surround line fittings with
shop towels to catch fluid bled from valve.
(11) Bleed first wheel brake unit as follows. Start
at left rear wheel:
(a) Open caliper or wheel cylinder bleed fitting
1/2 to 3/4 turn.
(b) Have helper press and hold brake pedal to
floor.
(c) Tighten bleed fitting and have helper release
brake pedal.
(d) Continue bleeding operation until fluid enter­
ing bleed container is clear and free of bubbles.
(12) Repeat bleeding operation at remaining wheel
brake units. Discard fluid bled into glass container. I t
should not be reused.
(13) Check and top off master cylinder reservoir
fluid level.
(14) Verify proper brake operation before moving
vehicle.
PRESSURE BLEEDING
The front brake metering valve (in the combi­
nation valve), must be held open when using
pressure bleeding equipment. This is necessary
because the 20 psi exerted by pressure equip­
ment exceeds the valve hold off point causing it
to close. The metering valve is in the forward
end of the combination valve. The valve stem is
accessible after removing the rubber protector
cap that covers the stem. The stem must be ei-