MCi Crusader II 1989 Maintenance Manual page 110

Date
1-1-89 ·
Page·_. __
3-_35 _ _
MC-9 MAINTENANCE MANUAL
WINDSHIELD WIPERS
Two heavy duty air operated "Air Push II" windshield wipers
are installed, one for each windshield. Individual control valves
with built•in air pressure regulators are provided on the front
dash. Regulators provide constant speed as adjusted by the
control valve. Air pressure variations do not affect wiper action.
Wiper motors are removable from the exterior of the coach.
Each motor incorporates a 2" (51 mm) diameter piston and a¾"
(16 mm) diameter drive shaft. Wipers are "self parking" panto-
graph with 20" (508 mm) flexible wiper blades.
MAINTENANCE
Wiper motor, control valves require no periodic mainte-
nance between overhaul. At overhaul, the windshield wiper
motors and wipers should be disassembled, cleaned and lubri-
cated with Sprague Wiper Lube. The following guidelines are to
be used on new or rebuilt wiper motors to increase service life.
A.
One of the best preventive actions is not to let the wiper
system sit too long without operation. Wiper systems should run
every other day. if only for a few cycles. This action will keep the
lubricant and O-rings movable and less likely to "take a set"
This is very important on older vehicles or systems which pass
along a large amount of air line contamination. Contaminants
tend to thin lubricant and wash it from the motor valve. It can be
strong enough to attack O-rings. causing swellipg and deterio•
ration.
B. If the system has seen heavy usage or is an older unit, it is
recommended that it be removed and updated with new
O-rings and fresh lubricant. Additional lubricants can be used
as a preventive maintenance or as a field fix for sticky units. If
O-rings are not damaged and the motor is not frozen, lubricant
injected in the air lines will keep a motor running. We recom-
mend that½ ounce be injected into each motor at a location as
close to the motor valve as possible Allow motor to run 15
minutes (remove arm or place a rag under blade) to work
through the valve.
Lubricating in this manner every six months is sufficient.
Where heavy contamination is present. more frequent applica-
tions may be required. We recommend using Sprague Wiper
Lube. part number Y -143. Do not use any type of penetrating
fluid or oil. While these will free a motor, they will break down
lubricants in the motor and attack O-rings. Only under emer-
gency situations should these be used and should be followed
by the addition of lubricating oil and, if possible, a breakdown
and manual regreasing of the motor.
C. Every 100,000 miles (161,000 km), the air strainer should
be disassembled and cleaned.
D. In-line oilers will a<:t as an air filter as well as keep a
supply of oil going to the wiper system. These should have a
drain and oil change at least twice a year.
E.
Alcohol injectors are very useful for vehicles operating in
severe cold conditions. Precautions should be taken to keep
sufficient lubricant in the motor as alcohol will tend to wash it
away. If used heavily, it may be necessary to remove the motor
valve and manually regrease unit.
WINDSHIELD WIPER ARM AND BLADE REPLACEMENT
During initial installation or spot check, be sure the motor is
in full park position. Be sure blade is assembled in the "blade
saddle" correctly. Tighten screw and nut assembly until snug.
Blade should have free movement in the saddle - do not
crush saddle over blade. If saddle portion of arm is notattched
to arm, be sure during assembly to place saddle on main wiper
. arm (larger of two), not on the follower (smaller of two). If not
already done, install follower arm and tighten nuts and bolts.
Parts should move freely in bearings.
WIPER BLADE ANGLE ADJUSTMENT
Pantograph shaft length is adjustable to allow setting wiper
blade angle. Each blade should travel across windshield in a
position so that when the arm is at the end of its outward
sweep, the wiper blade is parallel with the edge of the wind-
shield. Adjust angle of blade by placing blade rubber 1" from
molding while motor is in park position. By hand, move the
wiper arm to mid-position (perpendicular) on glass. Place
wiper blade in vertica[.position parallel with main arm.
Loosen lock nuts on pantograph shaft Remove crown nut
which attaches shaft arm to pivot shaft. Remove arm from
shaft. While holding outer end of pantograph shaft, turn shaft
arm to shorten or lengthen shaft assembly. Reinstall arm on
pivot shaft. Force arm and blade across wetted glass and
check angle of blade. Repeat if necessary, then install crown
nut on pivot shaft and tighten firmly. Tighten lock nuts on
·pantograph shaft
Turn motor unit to ON position; take note if wiper pattern is
centered and tips of wiper blades are not touching rubber
moldings. If the sweep is off center, it will be necessary to
move main arm clockwise or counterclockwise on diameter
segment to center the sweep. After each change it will be
necessary to re-center the blade in mid-position.
MOTOR DISASSEMBLY AND REPAIR
1. Remove windshield wiper blades. arms and pantograph
arms.
2. Remove wiper shaft spacer retainer nut. Remove left or
right hand corner moldings.
3. Disconnect air lines to wiper motor.
4. Remove wiper motor mounting panel retaining screws
and lift out the complete assembly.