Dodge RAM TRUCK 1500 1995 Service Manual page 218

5 - 46 ALL-WHEEL ANTILOCK BRAKE SYSTEM (ABS)
B R
screw and insert the opposite end of the hose in glass
container partially filled with brake fluid (Fig. 23). A
glass container makes it easier to see air bubbles as
they exit the bleed hose.
• Be sure the end of the bleed hose remains im­
mersed in fluid. This is necessary to prevent air from
being drawn back into the cylinder or caliper and
brakeline.
Do not allow the master cylinder to run out of fluid
when bleeding the brakes. An empty cylinder will al­
low additional air to be drawn into the system.
Check the cylinder fluid level frequently and add
fluid as needed.
J8905-18
Fig. 23 Typical Fluid Container And Bleed Hose
ABS MANUAL BRAKE BLEEDING PROCEDURE
(1) If master cylinder has been overhauled, or a
new cylinder will be installed, bleed cylinder on
bench before installation. This shortens bleed time
and ensures proper cylinder operation. Refer to pro­
cedure in Master Cylinder Service section.
(2) If master cylinder was not serviced, wipe cylin­
der reservoir and cover clean with shop towels. Use
Mopar brake cleaner if reservoir and cover are ex­
tremely dirty. Then remove cover and fill reservoir
with Mopar, DOT 3 brake fluid.
(3) Open all caliper and wheel cylinder bleed
screws. Close bleed screws when fluid starts dripping
from bleed screws. Then top off master cylinder res­
ervoir again.
(4) Bleed master cylinder first. Have helper oper­
ate brake pedal while bleeding each master cylinder
fluid outlet line.
(5) Bleed RWAL valve next and combination valve
afterward. Bleed each valve at brakeline fittings one
at a time. Surround line fittings with shop towels to
catch fluid from fittings.
(6) There are two bleed procedures for the front
antilock valve. If a new front valve is being installed,
bleed the valve as described in step (7). However, if
the original valve is still in the vehicle, bleed the
valve as described in step (8).
(7) If a new front antilock valve and motor as­
sembly is being installed, bleed new valve as fol­
lows:
(a) Loosen bleed plug on new front valve about
1/4 to one full turn (Fig. 23). Plug must be open to
fully bleed upper and lower sections of front an­
tilock valve.
(b) Remove cap from bleed valve stem (Fig. 24).
(c) Install Valve Depressor Tool 6670 on bleed
valve stem (Figs. 24 and 25). To install tool, slide
notched side of tool onto boss that surrounds bleed
valve stem (Fig. 25). Stem must be held inward (in
open position) to fully bleed upper section of new
valve assembly.
(d) Tighten thumbscrew on bleed Tool 6670 just
enough to push valve stem inward about 0.51 -
0.76 mm (0.020 - 0.030 in.).
(e) Apply brake pedal. Pedal will fall off signifi­
cantly when bleed plug is properly open and bleed
valve stem is correctly unseated (pressed inward)
by tool.
(f) Stroke brake pedal rapidly 5-10 times. This
action will fill upper and lower sections of valve
rapidly.
(g) Bleed new valve assembly at each brakeline
fitting one at a time. Remember to close valve
bleed plug before each brake pedal stroke. Con­
tinue bleeding until fluid flowing from fittings is
clear and free of bubbles.
(h) Remove depressor tool from valve stem and
install cap on stem. Then tighten bleed plug to 7-9
N-m (60-84 in. lbs.) torque.
(8) If original front antilock valve assembly is
still in place, bleed plug and bleed valve do not
have to be open during bleeding operations.
Just bleed the valve assembly at each brakeline fit­
ting one at a time.
(9) Bleed wheel brake units one at a time in rec­
ommended sequence and as follows:
(a) Bleed first wheel brake unit as follows. Start
at left rear wheel.
(b) Open caliper or wheel cylinder bleed fitting
1/2 to 3/4 turn.
(c) Have helper press and hold brake pedal to
floor.
(d) Tighten bleed fitting and have helper release
brake pedal.
(e) Continue bleeding operation until fluid flow­
ing into bleed fluid container is clear and free of
bubbles.