Freightliner Cargo Maintenance Manual - part 9

20–01 Radiator Cap Check

WARNING

Do not remove or loosen the radiator 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.

CAUTION

The radiator cap currently installed may not be the
same one installed when the vehicle was built. If
the radiator cap must be replaced, make sure that
it is the correct cap for the cooling system of the
vehicle. Because the radiator cap pressure rating
affects the operating temperature of the engine,
installing an improperly rated radiator cap may
have adverse effects on the cooling system, and
engine operating temperatures. This could cause
premature engine wear or damage.

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. Make sure that the re-
placement 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 damage.

20–02 Radiator Pressure Flush

and Coolant Change

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

Drain the radiator.

1.1

Remove the surge tank cap.

1.2

Open the petcock at the bottom of the
radiator to drain the engine coolant.

Disconnect the radiator inlet and outlet hose con-
nections.

Flush the radiator.

3.1

Attach a flushing gun nozzle to the radia-
tor outlet.

3.2

Run water in until the radiator is full.

3.3

Apply no more than 20 psi (138 kPa) air
pressure intermittently to help dislodge
sediment buildup in the core.

CAUTION

When flushing the radiator, do not apply more
than 20 psi (138 kPa) air pressure. Excessive pres-
sure can damage the radiator or heater core.

Drain the radiator, and flush the radiator until
clean water flows from the radiator. Remove the
flushing gun.

Close the petcock at the bottom of the radiator.

Connect the hoses. The hose clamps can be ei-
ther T-bolt clamps (

Fig. 1

) or Breeze Constant-

Torque clamps (

Fig. 2

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

When installing the Breeze Constant-Torque
hose clamps, the clamps must be tightened to
the correct torque. The screw tip of the clamp
must extend about 1/4 inch (6 mm) from the
clamp housing, and the Belleville washer stacks
must be collapsed almost flat. Use a torque

Engine Cooling/Radiator

Cargo Maintenance Manual, August 2003

20/1

wrench to install these hose clamps correctly.
The correct installation torque for Breeze
Constant-Torque hose clamps is as follows:

For Breeze Constant-Torque hose clamps with a
5/16-inch tightening screw hex:

55 lbf·in (620

N·cm).

For Breeze Constant-Torque hose clamps with a
3/8-inch tightening screw hex:

90 lbf·in (1020

N·cm).

NOTE: All hose clamps will lose torque after
installation due to "compression set." However,
when correctly installed, Breeze Constant-
Torque clamps will hold enough torque to auto-
matically adjust and keep consistent sealing

pressure. During vehicle operation and shut-
down, the screw tip may adjust according to
temperature and pressure changes. The torque
may need to be adjusted for individual applica-
tions.

Fill the radiator with coolant. Use a mixture of 50
percent water and 50 percent corrosion-inhibiting
antifreeze to protect the engine to –34°F (–37°C)
year round.

See

Table 1

for engine cooling system capacity

and

Table 2

for approved antifreezes.

Coolant Capacities

Engine Make and

Model

Radiator Core

and System Capacity

2 Row

quarts (liters)

3 Row

quarts (liters)

Cummins ISB

30.5 (28.9)

31.0 (29.3)

System capacity includes all hoses, fittings, and the heater core.

Table 1, Coolant Capacities

Approved Coolants

Engine Type

Coolant

Manufacturer

Coolant

Designation

Diesel

Texaco

JC04 Antifreeze

Van Waters and

Rogers Ltd.

(Canada)

Diesel

Antifreeze No.

6038

Freightliner-approved antifreeze must meet one of the following condi-

tions: A. Ethylene glycol solution that meets GM 6038–M Engineering Stan-
dards. B. Ethylene glycol solution that has less than 0.1% anhydrous so-
dium metasilicate, and meets either GM 1825–M or GM 1899–M
Engineering Standards.

Table 2, Approved Coolants

NOTE: You can mix purple-pink coolant (pre-
charged with a borate/nitrate-based additive)
with the common green coolant, although some
color change will be apparent.

02/28/96

f200326

Fig. 1, T-Bolt Type Hose Clamp

08/15/94

f200286

A. The screw tip must extend about 1/4 inch (6 mm).
B. The Belleville washer stacks must be collapsed

almost flat.

Tightening Screw Hex

Fig. 2, Breeze Constant-Torque Hose Clamp Installation

Engine Cooling/Radiator

Cargo Maintenance Manual, August 2003

20/2

Title of Maintenance Operation (MOP)

MOP Number

Clutch Inspection and Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25–02

Clutch Master Cylinder Fluid Level Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25–03

Clutch Release Bearing and Release Cross-Shaft Lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25–01

Clutch

Index, Alphabetical

Cargo Maintenance Manual, January 2000

25–01 Clutch Release Bearing

and Release Cross-Shaft
Lubrication

Clutch Release Bearing

CAUTION

Do not over-lubricate the release bearing. Over-
lubricating could contaminate the clutch internally,
causing clutch slippage and eventual clutch
failure.

On clutches with a grease-type release bearing
(

Fig. 1

), wipe the dirt from the grease fitting. Using a

pressure gun and high-temperature grease only, lu-
bricate the release bearing at the grease fitting until
the grease starts coming out of the fitting. Use only a
lithium-based grease that meets NLGI grade 1 or 2
specifications.

NOTE: On clutches with a sealed release bear-
ing, the release bearing is lubricated at the time
of manufacture and requires no additional

grease for the life of the bearing. This type of
release bearing is not equipped with a grease
fitting.

Clutch Release Cross-Shaft

The clutch release cross-shaft is equipped with two
grease fittings; one at each side of the transmission
clutch housing. Wipe the dirt from the grease fittings.
Using a pressure gun, lubricate the cross-shaft with
multipurpose chassis grease.

25–02 Clutch Inspection and

Adjustment

See Group 25 of the

Cargo Workshop Manual

for

clutch inspection and adjustment.

25–03 Clutch Master Cylinder

Fluid Level Check

The reservoir is full when the fluid level is up to the
"max" mark. The fluid level must always be above
the "min" mark. Use only heavy-duty brake fluid,
DOT 3, in the hydraulic-clutch system.

f250081a

05/27/93

Fig. 1, Release Bearing Grease Fitting

Clutch

Cargo Maintenance Manual, January 2000

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Content .. 7 8 9 10 ..