Freightliner Truck 108SD: Monthly Post-Trip Inspection and Maintenance

Brake Component Inspection

Walk around the vehicle and visually the brake system components for visible damage.

Inspect all visible brake system components for missing fasteners or signs of looseness, such as rust tracks.

Inspect the exterior surfaces of brake chambers for damage. Make sure that breather holes are open and free of debris.

NOTE: Do not route air brake lines on top of anything likely to be stepped on.

Inspect air brake lines for dents, swelling, kinks, twisting, abrasion, and damage, especially near moving parts.

Inspect flex air lines for deterioration or signs of abrasion.

Inspect for cracked, worn, or oil-contaminated brake linings and brake drums (or rotors).

Check the thickness of the brake linings. Re- place brake linings on all brake assemblies on the axle if any brake linings are worn to less than approximately 1/4 inch (6.4 mm) at the thinnest point.

Saddle Tank Areas Inspection

If the water drained from the air reservoirs is cloudy or oily, it may indicate a problem with the compressor. If oil is allowed to contaminate the air dryer, it will not remove the water from the air brake system, which could adversely affect braking.

Drain the brake system air reservoirs (reservoirs with automatic drain valves only).

Inspect the batteries.

Remove the battery box cover and inspect all visible battery cables for loose wiring or damage. See Fig. 21.15.
Check that the battery hold-down is secure.

Inspect the following aerodynamic components, if equipped, for structural damage, cracks, or wear.

Engine Compartment Inspection and Adjustments

Inspect the bumper and hood for structural dam- age, cracks, or wear.

Inspect the radiator and heater hoses, including the clamps and support brackets.

Make sure the radiator inlet and outlet hoses are pliable and are not cracking or ballooning.
Make sure the heater hoses are pliable and are not cracking or ballooning.
Tighten hose clamps as necessary.

Check the steering wheel for excessive play.

Start the engine. With the front tires straight ahead, turn the steering wheel until motion is observed at the front wheels.
Align a reference mark on the steering wheel to a rule, then slowly turn the steering wheel in the opposite direction until motion is again detected at the wheels.
Measure the lash (free play) at the rim of the steering wheel. Excessive lash exists if steering wheel movement exceeds 2-1/2 inches (64 mm) with a 20-inch (508-mm) steering wheel, or 2-1/4 inches (57 mm) with an 18-inch (450-mm) steering wheel.
If there is excessive lash, check the steering system for wear or incorrect adjustment before operating the vehicle.

Natural Gas Fuel System Inspection, If Equipped

Leak test all fuel system components, joints, and fittings using a methane detector. A bubble solu- tion can be used to pinpoint the exact location of leaks.

Replace any leaking or damaged fuel tanks and fuel lines; repair or replace leaking or damaged fittings.

Drain the CNG high-pressure fuel filter housing, if equipped.

Purge the CNG fuel lines by closing the CNG fuel cylinder shutoff valves. Start the engine and let it idle until the fuel lines are empty and the engine stops.
Close the manual fuel shutoff valve on the fuel panel.
Remove the two capscrews that secure the access cover to the fuel panel, then remove the access cover. See Fig. 21.16. Save the capscrews for installation.
Slowly open the bleed valve on the manifold to relieve remaining fuel pressure within the system. See Fig. 21.17.
Put a clean receptacle under the filter assembly.
Using an 11/16-inch wrench, remove the drain plug from the filter bowl.
Close the bleed valve on the manifold and open the manual fuel shutoff valve on the fuel panel. Open the fuel cylinder shutoff valves.
Use a methane detector to leak test all fuel system components between the fuel cylinders and the solenoid valve. A bubble solution can be used to pinpoint the exact location of leaks. Repair or replace any leaking components.
Install the access cover on the fuel panel.

Fig. 21.17, CNG Fuel Panel Components

Brake Component Inspection

Walk around the vehicle and visually the brake system components for visible damage.

Inspect all visible brake system components for missing fasteners or signs of looseness, such as rust tracks.

Inspect the exterior surfaces of brake chambers for damage. Make sure that breather holes are open and free of debris.

NOTE: Do not route air brake lines on top of anything likely to be stepped on.

Inspect air brake lines for dents, swelling, kinks, twisting, abrasion, and damage, especially near moving parts.

Inspect flex air lines for deterioration or signs of abrasion.

Inspect for cracked, worn, or oil-contaminated brake linings and brake drums (or rotors).

Check the thickness of the brake linings. Re- place brake linings on all brake assemblies on the axle if any brake linings are worn to less than approximately 1/4 inch (6.4 mm) at the thinnest point.

Saddle Tank Areas Inspection

If the water drained from the air reservoirs is cloudy or oily, it may indicate a problem with the compressor. If oil is allowed to contaminate the air dryer, it will not remove the water from the air brake system, which could adversely affect braking.

Drain the brake system air reservoirs (reservoirs with automatic drain valves only).

Inspect the batteries.

Remove the battery box cover and inspect all visible battery cables for loose wiring or damage. See Fig. 21.15.

Check that the battery hold-down is secure.

Inspect the following aerodynamic components, if equipped, for structural damage, cracks, or wear.

Chassis fairings

Roof fairing/deflector

Side skirts

Cab extenders

Battery access cover

Engine Compartment Inspection and Adjustments

Inspect the bumper and hood for structural dam- age, cracks, or wear.

Inspect the radiator and heater hoses, including the clamps and support brackets.

Make sure the radiator inlet and outlet hoses are pliable and are not cracking or ballooning.

Make sure the heater hoses are pliable and are not cracking or ballooning.

Tighten hose clamps as necessary.

Check the steering wheel for excessive play.

Start the engine. With the front tires straight ahead, turn the steering wheel until motion is observed at the front wheels.

Align a reference mark on the steering wheel to a rule, then slowly turn the steering wheel in the opposite direction until motion is again detected at the wheels.

Measure the lash (free play) at the rim of the steering wheel. Excessive lash exists if steering wheel movement exceeds 2-1/2 inches (64 mm) with a 20-inch (508-mm) steering wheel, or 2-1/4 inches (57 mm) with an 18-inch (450-mm) steering wheel.

If there is excessive lash, check the steering system for wear or incorrect adjustment before operating the vehicle.

Natural Gas Fuel System Inspection, If Equipped

Leak test all fuel system components, joints, and fittings using a methane detector. A bubble solu- tion can be used to pinpoint the exact location of leaks.

Replace any leaking or damaged fuel tanks and fuel lines; repair or replace leaking or damaged fittings.

Drain the CNG high-pressure fuel filter housing, if equipped.

Purge the CNG fuel lines by closing the CNG fuel cylinder shutoff valves. Start the engine and let it idle until the fuel lines are empty and the engine stops.

Close the manual fuel shutoff valve on the fuel panel.

Remove the two capscrews that secure the access cover to the fuel panel, then remove the access cover. See Fig. 21.16. Save the capscrews for installation.

Slowly open the bleed valve on the manifold to relieve remaining fuel pressure within the system. See Fig. 21.17.

Put a clean receptacle under the filter assembly.

Using an 11/16-inch wrench, remove the drain plug from the filter bowl.

Close the bleed valve on the manifold and open the manual fuel shutoff valve on the fuel panel. Open the fuel cylinder shutoff valves.

Use a methane detector to leak test all fuel system components between the fuel cylinders and the solenoid valve. A bubble solution can be used to pinpoint the exact location of leaks. Repair or replace any leaking components.

Install the access cover on the fuel panel.

Fig. 21.17, CNG Fuel Panel Components