TRUCK SERVICE MANUAL
ENGINE
When full, apply air pressure gradually to avoid damage
Check Thermostats And Seals (Fall)
to core. Shut off air and allow radiator to refill; then apply
Remove thermostats from thermostat housings and
air pressure. Repeat until water coming from radiator is
check for proper opening and closing temperature.
clean.
Most Cummins Engines are equipped with either
Sediment and dirt settle into pockets in block as well as
medium 170 to 185 deg. F [77 to 85 deg. C] or low 160
radiator core. Remove thermostats from housing and
to 175 deg. F [71 to 79 deg. C] and in a few cases high-
flush block with water. Partially restrict lower opening
range 180 to 195 deg. F [82 to 91 deg. C] thermostats,
until block fills. Apply air pressure and force water from
depending on engine application.
lower opening. Repeat process until stream of water
coming from block is clean.
Checking Mountings
Tighten Mounting Bolts And Nuts (As Required)
Check Hose (Spring And Fall)
Inspect oil filter and cooling system hose and hose
Engine mounting bolts will occasionally work loose and
connections for leaks and/or deterioration. Particles of
cause the engine supports and brackets to wear rapidly.
deteriorated hose can be carried through cooling system
Tighten all mounting bolts or nuts and replace any
or lubricating system and restrict or clog small passages,
broken or lost bolts or capscrews.
especially radiator core, and lubricating oil cooler, and
slow or partially stop circulation. Replace as necessary.
Tighten Turbocharger Mounting Nuts
(As Required)
Clean Electric Connections (Spring And Fall)
Tighten all turbocharger mounting capscrews and nuts to
Hard starting is often traceable to loose or corroded
be sure that they are holding securely. Tighten mounting
battery connections. A loose connection will overwork
bolts and supports so that vibration will be at a minimum.
alternator and regulator and shorten their lives.
Fig. 2-70.
1.
Add water (distilled) to battery cells as required.
Check solution level every 15 days during hot weather,
every 30 days during cold weather, keep solution filled to
3/8 inch [9.5 mm] above separator plates.
2.
Remove corrosion from around terminals; then
coat with petroleum jelly or a non-corrosive inhibitor.
3.
Keep connections clean and tight. Prevent wires
and lugs from touching each other or any metal except
screw terminals to which they are attached.
4.
Replace broken or worn wires and their
terminals.
5.
Have battery tested periodically. Follow battery
manufacturer's instructions for maintenance.
Check Cold-Starting Aid (Fall)
Remove 1/8 inch pipe plug from manifold, near glow
Fig. 2-70, (N11953) Tightening turbocharger mounting
plug, and check operation of preheater as described in
nuts
Operators Manual.
Check Fan And Drive Pulley Mounting (Spring And
Check Shutterstats And Thermatic Fans (Fall)
Fall)
Shutterstats and thermatic fans must be set to operate in
Check fan to be sure it is securely mounted; tighten
same range as thermostat with which they are used.
capscrews as necessary. Check fan for wobble or bent
Table 2-18 gives settings for shutterstats and thermatic
blades.
fans as normally used. The 180 to 195 deg. F [82 to 91
deg. C] thermostats are used only with shutterstats that
Check fan hub and crankshaft drive pulley to be sure
are set to close at 187 deg. F [86 deg. C] and open at
they are securely mounted. Check fan hub pulley for
195 deg. F [91 deg. C].
looseness or wobble; if necessary, remove fan pilot hub
and tighten the shaft nut. Tighten the fan bracket
capscrews.
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