Freightliner Columbia. Manual - part 8

Safety Precautions

DANGER

When working on the vehicle, shut down the en-
gine, set the parking brake, and chock the tires.
Before working under the vehicle, always place
jack stands under the frame rails to ensure the
vehicle can not drop. Failure to follow these steps
could result in serious personal injury or death.

15–01 Alternator, Battery, and

Starter Connections
Check

WARNING

Batteries generate explosive gas as a by-product
of their chemical process. Do not smoke when
working around batteries. Put out all flames and
remove any source of sparks or intense heat in
the vicinity of the battery compartment. Make sure
the battery compartment has been completely
vented before disconnecting or connecting the
battery cables.

Battery acid is extremely harmful if splashed in
the eyes or on the skin. Always wear a face shield
and protective clothing when working around
batteries.

Disconnect the batteries.

Check the tightness of the alternator bracket fas-
teners; tighten the fasteners as needed. For
torque values, see Group 15 of the Columbia®
Workshop Manual.

Check the belt tension of the alternator drive
belt. Place a tension gauge at the belt’s widest
span, and adjust the belt tension to specification.

See

Group 01

for belt tension specifications.

Some engines are equipped with dual alternator
belts; always check both belts for correct tension.
Check that the tensioner operates smoothly with-
out binding. Engines equipped with a serpentine,
or poly-V belt have automatic belt tensioners and
do not require belt tension inspection.

Check that all electrical connections at the alter-
nator and starter are clean. Clean and tighten all

charging system electrical connections, including
the connections at the starter B terminal and
ground terminal, and where the alternator charg-
ing cable terminates.

Inspect the battery cables for wear, and replace
them if they are damaged. Clean the cable con-
nector terminals with a wire brush. See Group
54 of the Columbia® Workshop Manual for
troubleshooting instructions, and for adjustment,
repair, or replacement instructions.

5.1

Clean and tighten the battery ground
cable, terminal, and clamps.

5.2

Inspect the retainer assembly or battery
hold-downs, and the battery box. Replace
worn or damaged parts. Remove any cor-
rosion with a wire brush, and wash with a
weak solution of baking soda and water.
Flush with clean water, and dry. Paint the
retainer assembly if needed, to prevent
rusting.

5.3

Check that foreign objects such as
stones, bolts, and nuts are removed from
the battery box.

5.4

After cleaning, connect the cables to the
batteries and tighten them to the torque
specifications listed on the battery, gener-
ally 10 to 15 lbf·ft (14 to 20 N·m).

5.5

Coat the battery terminals with dielectric
grease.

Check the alternator wiring for missing insulation,
kinks, and heat damage. Replace or repair as
needed.

Check the terminals on the battery shut-off
switch and the magnetic switch. Make sure the
terminal connections are clean and tight. Coat
the terminal connections with dielectric red
enamel after cleaning.

Alternators and Starters

15/1

Title of Maintenance Operation (MOP)

MOP Number

Fan Clutch Check (Noise Emission Control) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20–03

Pressure Relief Cap Check. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20–01

Radiator Pressure-Flushing and Coolant Change. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20–02

Safety Precautions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Engine Cooling/Radiator

Index, Alphabetical

Safety Precautions

DANGER

20–01 Pressure Relief Cap

Check

WARNING

Do not remove or loosen the surge tank cap until
the engine and cooling system have completely
cooled. Use extreme care when removing the cap.
A sudden release of pressure from removing the
cap prior to the system cooling can result in a
surge of scalding coolant that could cause seri-
ous personal injury.

Remove the fill cap, first, to relieve the cooling
system pressure, then remove the SAE cap.

Using a radiator-cap tester, check the pressure
cap to see if it maintains pressure to within 10%
of the pressure rating marked on the cap. If it
doesn’t, replace the cap. See

Fig. 1

. Make sure

that the replacement radiator cap is correctly
rated for the cooling system of the vehicle.

There is a second valve in the radiator cap that
opens under vacuum. This prevents the collapse
of hoses and other parts that are not internally
supported when the system cools. Inspect the
vacuum-relief valve to be sure it is not stuck.

Make sure that the cap seals properly on the
coolant filler neck seat, and that the radiator cap
gasket is not damaged. On vehicles with
screw-on caps with O-rings, make sure that the
O-ring is not cracked or deteriorated. Replace
the cap if the gasket shows deterioration or dam-
age.

20–02 Radiator Pressure-

Flushing and Coolant
Change

NOTE: For additional instructions on cleaning
and flushing the engine cooling system, see the
applicable engine manufacturer’s maintenance
and operation manual.

Park the vehicle and apply the parking brakes.
Tilt the hood.

Place a suitable container under the elbow of the
radiator outlet pipe and the radiator. The con-
tainer should hold at least 60 quarts (59 liters) of
fluid.

WARNING

Remove the surge tank cap.

WARNING

Do not attempt to drain the cooling system until
the coolant and engine are cool. Draining the
cooling system prior to the system cooling could
cause severe personal injury due to scalding.

Remove the drain plugs at the radiator side tank
and at the lower radiator outlet pipe elbow. See

Fig. 2

. Allow the coolant to drain.

Disconnect the radiator upper and lower hoses,
and install the surge tank cap. Attach the flushing
gun nozzle to the radiator at the lower radiator
hose opening. Run the water until the radiator is
full.

CAUTION

When flushing the radiator, do not apply more
than 15 psi (100 kPa) air pressure. Excessive pres-
sure can damage the radiator.

Engine Cooling/Radiator

20/1

Gradually, apply air pressure to help dislodge
sediment built up in the radiator core. Do not
apply more than 15 psi (100 kPa) air pressure to
the radiator. Pressures exceeding 15 psi (100
kPa) could damage the radiator core.

Shut off the air at the pressure gun nozzle and
allow the radiator to refill with water.

Repeat the previous two steps until clean water
flows from the radiator.

Remove the radiator side-tank drain plug and
allow the radiator to drain. Install and tighten the
side-tank drain plug and the radiator outlet pipe
drain plug after the radiator has been drained.
Do not overtighten the plugs.

10. Connect the hoses. Your hose clamps can be

either T-bolt clamps (see

Fig. 3

) or Breeze

Constant-Torque clamps (see

Fig. 4

When working with T-bolt hose clamps, tighten
the clamps 55 lbf·in (620 N·cm). These clamps
are now standard on hoses with an inside diam-
eter greater than 2 inches (51 mm).

f500244

06/08/95

Low-Coolant-Level Sensor

SAE Cap (for coolant overflow pressure relief only)

Fill Cap

Fig. 1, Surge Tank

f011008

06/29/95

NOTE: Cummins engine shown.

Coolant Drain Plug

Fig. 2, Coolant Drain Plug Location

Engine Cooling/Radiator

20/2

Content .. 6 7 8 9 ..