Pre- and Post-Trip Inspections and Maintenance

Safety Precautions

DANGER
When working on the vehicle, shut down the engine, 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.

Daily Pretrip Inspection and Maintenance

Complete the following inspection and maintenance procedures to ensure that vehicle components are in good working condition before each trip. A driver who is familiar with the vehicle and drives it regularly can perform the daily inspections, then add the weekly and monthly post-trip inspections as scheduled.
If the driver does not operate the vehicle on a consistent basis, all daily, weekly, and monthly inspection and maintenance procedures should be performed before the trip.
IMPORTANT: The pre- and post-trip checklists, inspections, and maintenance procedures detailed in this chapter are not all-inclusive . Refer to other component and body manufacturers' instructions for specific inspection and maintenance instructions, as well as local, state, and federal guidelines.
NOTE: If any system or component does not pass this inspection, it must be corrected before operating the vehicle. Whenever equipment requires adjustment, replacement, and/or repair, see the Century Class Trucks Workshop Manual for procedures and specifications.

Suspension and Slack Adjuster Inspection

Walk around the vehicle and visually inspect suspension and slack adjuster components.
1.
Inspect the following suspension components for signs of structural damage, cracks, or wear.
springs
spring hangers
shocks
suspension arms
suspension brackets
axle seats
bushings
2.
Inspect slack adjusters for signs of damage. See Fig. 23.1 , Fig. 23.2 , or Fig. 23.3 .
  • 1. 7/16-inch Adjusting Nut
  • 2. Grease Fitting
  • 3. Boot
  • 4. Link
  • 5. Brake Chamber Piston Rod
  • 6. Clevis
  • 7. ½-inch Clevis Pin
  • 8. 1/4-inch Clevis Pin
  • 9. Grease Relief Opening
  • 10. Slack Adjuster Spline
Fig. 23.1, Gunite Automatic Slack Adjuster
  • 1. Clevis
  • 2. Slack Adjuster
  • 3. Clevis Pin
  • 4. Manual Adjusting Nut
  • 5. Control Arm
  • 6. Control-Arm Washers and Nut
  • 7. Anchor Strap Slot
  • 8. Anchor Strap
  • 9. Brake Chamber
Fig. 23.2, Haldex Automatic Slack Adjuster
  • 1. Grease Fitting (if equipped)
  • 2. Slack Adjuster Housing
  • 3. Brake Chamber Pushrod
  • 4. Clevis
  • 5. Clevis Pin (large)
  • 6. Clevis Pin (small)
  • 7. Actuator Rod
  • 8. Boot
  • 9. Manual Adjusting Nut
  • 10. Camshaft Splines
Fig. 23.3, Meritor Automatic Slack Adjuster
Inspect slack adjuster boots, if equipped, for cuts or tears.
Inspect anchor straps, if equipped, for damage.
Look for worn clevis pins on brake chamber pushrods.
Look for missing or damaged cotter pins on the clevis pins.
Ensure chamber piston rods are in line with the slack adjusters.

Wheel and Tire Inspection

Walk around the vehicle and visually inspect each wheel and tire assembly.
1.
Inspect each tire for the following:
valve stem caps on every tire, screwed on finger-tight
bulges, cracks, cuts, and penetrations
oil contamination (petroleum derivatives will soften the rubber and destroy the tire)
tread depth—if tread is less than 4/32 inch (3 mm) on any front tire, or less than 2/32 inch (1.5 mm) on any rear tire, replace the tire
debris lodged between duel tire sets
2.
Check tire inflation.
2.
For inflation pressures and maximum loads, see the tire manufacturer's guidelines. Inflate the tires to the applicable pressures if needed.
2.
If a tire has been run flat or under-inflated, check the wheel and tire for damage before adding air.
2.
Keep compressed air reservoirs and lines dry during tire inflation. Use well-maintained inline moisture traps and service them regularly.
WARNING
Do not operate the vehicle with underinflated or overinflated tires. Incorrect inflation can stress the tires and make the tires and rims more susceptible to damage, possibly leading to rim or tire failure and loss of vehicle control, resulting in serious personal injury or death.
NOTICE
A weekly pressure loss of 4 psi (28 kPa) or more in a tire may indicate damage. The tire should be inspected and, if necessary, repaired or replaced by a qualified tire service facility.
IMPORTANT: The load and cold inflation pressure must not exceed the rim or wheel manufacturer's recommendations, even though the tire may be approved for a higher load inflation. Consult the rim or wheel manufacturer for the correct tire inflation pressure for the vehicle load.
3.
Examine each rim and wheel component.
3.1
Remove all dirt and debris from the assembly. Rust streaks or metal build-up around stud holes, or out-of-round or worn stud holes, may be caused by loose wheel nuts.
WARNING
Have any worn or damaged wheel components replaced by a qualified person using the wheel manufacturer's instructions and the wheel industry's standard safety precautions and equipment. Otherwise a vehicle or workshop accident could occur, possibly resulting in serious personal injury or death.
3.2
Inspect for broken, cracked, badly worn, bent, rusty, or sprung rings and rims.
NOTICE
Use the recommended torque values and follow the proper tightening sequence. Insufficient wheel nut torque can cause wheel shimmy, resulting in wheel damage, stud breakage, and extreme tire tread wear. Excessive wheel nut torque can break studs, damage threads, and crack discs in the stud hole area.
3.3
Make sure all wheel nuts are tightened. If tightening is necessary, use the tightening pattern in Fig. 23.4 or Fig. 23.5 to initially tighten the flange nuts to 50 to 100 lbf·ft (68 to 136 N·m). Then tighten the flange nuts to 450 to 500 lbf·ft (610 to 678 N·m).
Fig. 23.4, Tightening Pattern, 10-Hole Wheels
Fig. 23.5, Tightening Pattern, 8-Hole Wheels
4.
Inspect the outboard side of all wheel hubs and the hub oil seal area on the inboard side of each wheel for signs of oil leakage. If any oil is found on wheel and tire or brake components, remove the vehicle from service until the leak has been fixed.
4.
If needed, fill the hubs to the level indicated on the hub cap. See Group 35 of the Century Class Trucks Maintenance Manual for recommended lubricants.
5.
Check that mud flaps are undamaged and hang 10 inches (25.4 cm) or less from the ground.

Saddle Tank Area Inspections

WARNING
When draining the air reservoir, do not look into the air jets or direct them toward anyone. Dirt or sludge particles may be in the airstream and could cause injury.
NOTICE
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.
1.
Drain the brake system air reservoirs (reservoirs without automatic drain valves only).
WARNING
Never operate the engine with the fuel tank shutoff valves partially closed. This could damage the fuel pump, causing sudden loss of engine power, possibly resulting in serious personal injury due to reduced vehicle control.
2.
Ensure fuel tanks are secured to their mounting brackets and that the mounting brackets are secured to the frame.
2.
If equipped with fuel tank shutoff valves, be sure the valves are fully open.
3.
Inspect visible frame rails for missing bolts, shiny areas, or rust streaks. Check all visible crossmembers for damage or signs of looseness.
4.
Inspect visible components of the exhaust system to ensure connections are tight.
4.
Inspect upstream of the aftertreatment device (ATD), if equipped, for cracking or signs of leaks, such as soot trails. Inspect downstream of the ATD for signs of exhaust leaks, such as blistering or warping of nearby components.
NOTICE
Failure to maintain a sealed air intake system could allow the entry of dirt and contaminants into the engine. This could adversely affect engine performance and result in engine damage.
5.
Inspect the air intake system for leaks or damage. Ensure the snorkel intake is free of debris, if equipped.
5.
Push the reset button on the air intake restriction indicator located on the air cleaner, if equipped.

Forward Engine Compartment Inspection

Open the grille. See Chapter 2 for instructions.
1.
Check the ground underneath the engine for fuel, oil, or coolant leaks.
2.
Check the engine oil level.
NOTICE
Operating the engine with the oil level below the minimum fill (or "add") mark or above the maximum fill (or "full") mark could result in engine damage.
2.1
Check the oil level with the vehicle parked on a level surface. See Fig. 23.6 . See the engine manufacturer's guidelines for engine shutdown time requirements prior to checking the oil level.
  • 1. Dipstick
  • 2. Coolant Fill Cap
Fig. 23.6, Oil Level Checking
IMPORTANT: On engines that are equipped with an exhaust aftertreatment system (ATS), use engine oil with less than 1% sulfated ash.
2.2
If the oil level is at or below the minimum fill (or "add") mark on the dipstick, add enough oil to maintain the level between the minimum and maximum fill marks. See the engine operation manual for recommended lubricants.
NOTICE
Low coolant could result in engine overheating, which could cause engine damage.
IMPORTANT: The surge tank must be cool to check the coolant level.
3.
Check the engine coolant level in the radiator surge tank. See Fig. 23.6 .
NOTICE
Coolant must be filled to the full line of the surge tank. Low coolant could result in engine overheating, which could cause engine damage.
3.1
If the coolant is low, fill the surge tank to the full line with a 50/50 mixture of water and the type of antifreeze currently installed in your vehicle.
3.2
If the surge tank was empty, start the engine after refilling and check the level again when the engine is at operating temperature.
WARNING
Washer fluids may be flammable and poisonous. Do not expose washer fluid to an open flame or any burning material, such as a cigarette. Always comply with the washer fluid manufacturer's recommended safety precautions.
4.
Check the windshield washer reservoir fluid level. See Fig. 23.7 .
  • 1. Washer Reservoir Fill Tube
Fig. 23.7, Windshield Washer Reservoir Location (right-hand side location shown)

Cab Inspection

1.
Push the reset button on the dash-mounted air intake restriction indicator, if equipped.
2.
With the ignition switch in the OFF position, check the air-pressure warning system.
2.1
If not previously drained, drain the air reservoirs using moderate brake applications until pressure in both reservoirs is less than 70 psi (483 kPa).
2.2
Turn the ignition to the ON position. The ICU will complete a full gauge sweep and bulb check, and an audible warning will sound. Ensure the low air pressure lamp remains illuminated and an audible warning continues to sound after the gauge sweep is complete.
3.
Check air governor cut-in and cut-out pressures.
3.1
Start the engine and ensure the low air pressure lamp goes out and the buzzer silences when pressure reaches approximately 70 psi (483 kPa) in both air reservoirs.
3.1
The air governor should cut out at approximately 120 psi (827 kPa). For vehicles with an optional dryer reservoir module (DRM), the cut-out pressure is approximately 130 psi (896 kPa).
3.2
With the engine idling, apply the brake pedal several times. The air governor should cut in when pressure in the primary air reservoir (top air gauge) reaches approximately 100 psi (690 kPa).
4.
Check air pressure build-up time.
4.1
With the air system fully charged, make one full brake application and note the air pressure reading on the primary air gauge.
4.2
Further reduce air pressure using moderate brake applications, then run the engine at governed rpm.
4.3
Note the time that the pressure reaches the previously noted reading on the primary air gauge, then note the time that the air pressure reaches cut-out pressure.
4.4
If it takes longer than 30 seconds to reach cut-out pressure after the primary air gauge passes the previously noted pressure (noted after one full brake application), eliminate any leaks or replace the air compressor before operating the vehicle.
5.
Check air leakage in the system.
5.1
With the parking brake applied, the transmission out of gear, and the air system fully charged, release the service brakes and shut down the engine.
5.2
Wait one minute and note the air pressure drop in psi (kPa) per minute from the primary air reservoir.
5.2
If the pressure drop exceeds the limits shown in Table 23.1 , eliminate any leaks before operating the vehicle.
Maximum Allowable Air Leakage
Description
Pressure Drop:
psi (kPa) Per Minute
Released
Applied
Truck or Tractor Only
2 (14)
3 (21)
Truck or Tractor w/Single Trailer
3 (21)
4 (28)
Truck or Tractor w/Two Trailers
5 (34)
6 (41)
Table 23.1, Maximum Allowable Air Leakage
6.
Check the air pressure reserve.
6.
With the engine still off, make one full brake application and observe the pressure drop on the primary air gauge. If pressure drops more than 25 psi (172 kPa), eliminate any leaks before operating the vehicle.
WARNING
When cleaning windshields and windows, always stand on the ground or on a secure ladder or platform. Use a long-handled window cleaner. Do not use the cab steps, tires, fenders, fuel tanks, engine, or under-hood components to access the windshield or windows. Doing so could cause a fall and result in an injury.
7.
Inspect the mirrors, window glass, and windshield for cracks or other damage.
8.
Ensure that the horn, windshield wipers, and windshield washers are operating properly. These devices must be in good working order for safe vehicle operation.
9.
Ensure the heater and defroster are operating properly.
10.
Check the operation of all interior lights.
10.1
Turn on the headlights and leave them on. Ensure all equipped gauge bulbs illuminate in the dash message center.
10.2
Ensure all equipped driver control switches illuminate.
10.3
Ensure both turn signal indicator bulbs illuminate in the dash message center when the turn signal switch is activated.
11.
Check the operation of all exterior lights. See Fig. 23.8 .
  • 1. Fog Light
  • 2. Headlight
  • 3. Front Turn Signal
  • 4. Sidewall Turn Signal
  • 5. Clearance Light
  • 6. Marker Lights
Fig. 23.8, Exterior Lights
11.1
Activate the high-beam headlights and hazard warning lights.
11.2
Exit the cab and check that all exterior lights and reflectors are clean and intact.
11.3
Check that the brake lights, taillights, headlights, turn signals, marker lights, identification lights, and clearance lights are working properly.
12.
Inspect the seat belts and tether belts.
WARNING
Inspect and maintain seat belts. When any part of a seat belt system needs replacement, the entire seat belt must be replaced, both retractor and buckle side. Any time a vehicle is involved in an accident, and the seat belt system was in use, the entire vehicle seat belt system must be replaced before operating the vehicle. Do not attempt to modify the seat belt system; doing so could change the effectiveness of the system. Failure to replace worn or damaged seat belts, or making any modifications to the system, may result in personal injury or death.
12.1
Check the web for fraying, cuts, extreme dirt and dust, or for severe fading from exposure to sunlight, especially near the buckle latch plate and in the D-loop guide area.
12.2
Check operation of the buckle, latch, web retractor, and upper seat belt mount on the door pillar. Check all visible components for wear or damage.
12.3
Check the seat belt and tether belt connection points and tighten any that are loose.
WARNING
Never fill fuel tanks to more than 95 percent of their liquid capacity. This could make them more likely to rupture from impact, possibly causing fire and resulting in serious personal injury or death by burning.
Do not mix gasoline or alcohol with diesel fuel. This mixture could cause an explosion, possibly resulting in serious personal injury or death. Do not fill the fuel tanks in the presence of sparks, open flames, or intense heat. These could ignite the fuel, possibly causing severe burns.
IMPORTANT: On engines that are equipped with an exhaust ATS, use ultralow-sulfur diesel (ULSD) with 15 ppm sulfur content or less.
13.
Check the fuel level in the fuel tank(s). To keep condensation to a minimum, fuel tanks should be filled at the end of each day.
14.
Adjust the rearview and down view mirrors as necessary.
15.
Test the service brakes.
15.1
With the engine running and air system fully charged, set the parking brake.
15.2
Put the vehicle in the lowest gear and gently attempt to move it forward. The vehicle should not move.
15.2
If the vehicle moves, the parking brakes are not operating correctly and must be repaired before the vehicle is operated.
16.
Test the backup alarm.
16.1
Release the parking brake and put the transmission in reverse.
16.2
Move the vehicle slightly backward to ensure that the backup alarm is operating correctly.

Weekly Post-Trip Inspections and Maintenance

Air Intake System Inspection

After resetting the air intake restriction indicator during the daily pretrip inspection, check the indicator again with the engine off.
1.
Check an indicator with graduations to see if air restriction exceeds the value shown in Table 23.2 .
1.
Check a go/no-go indicator without graduations to see if the colored bar shows through the clear window.
Air Intake Maximum Restriction Values: inH2O (mmH2)
Engine Make
Pre-EPA07 (ADR 80/02) Engines
EPA07 (ADR 80/03) Engines
Cummins
25 (635)
25 (635)
Detroit
20 (255)
22 (560)
Mercedes-Benz
22 (560)
22 (560)
Table 23.2, Air Intake Maximum Restriction Values
2.
If air restriction exceeds the maximum allowable value, operate the vehicle for one more day, making sure not to run the engine over rated rpm. Refer to the engine operation manual for more information on rated rpm for your engine.
2.
If air restriction exceeds the maximum value again, replace the air cleaner. For instructions, refer to Group 09 of the Century Class Trucks Workshop Manual .

Engine Compartment Inspection

Tilt the cab. See Chapter 2 for instructions.
1.
Check for water in the fuel/water separator, if equipped.
IMPORTANT: When draining fluid from a fuel/water separator, drain the fluid into an appropriate container and dispose of it properly. Many jurisdictions now issue fines for draining fuel/water separators onto the ground.
1.1
Place a suitable container under the fuel/water separator.
NOTE: A hose may be used to direct water into the container. Use a hose with a ½-inch pipe thread on DAVCO models.
IMPORTANT: Water in the fuel/water separator will appear as beads. Drain the fuel/water separator only enough to remove the water. Stop draining fluid when fuel begins to drain out. If the fuel/water separator is drained of fuel, it will be necessary to prime the fuel system before the vehicle can be started again.
1.2
If the engine is equipped with a built-in water separator, loosen the drain valve, and allow the water to run out. Close the drain valve, taking care not to overtighten it.
1.3
Alliance/Racor Models : Turn the drain plug counterclockwise to open it. See Fig. 23.9 .
1.3
DAVCO Models : Remove the vent cap and open the drain. See Fig. 23.10 .
  • 1. Washers (qty 2)
  • 2. Nuts (qty 2)
  • 3. Frame Rail
  • 4. Fuel Outlet Port
  • 5. Fuel Inlet Port
  • 6. Priming Pump
  • 7. Mounting Head
  • 8. Mounting Bolts (qty 2)
  • 9. Filter Element
  • 10. Sight Bowl
  • 11. Drain Plug
Fig. 23.9, Alliance Fuel/Water Separator Assembly and Installation
  • 1. Drain Valve
  • 2. Lower Housing
  • 3. Clear Cover
  • 4. Vent Cap
  • 5. Collar
  • 6. Inlet Port/Check Valve
Fig. 23.10, DAVCO Fuel/Water Separator (Fuel Pro 382 shown)
1.4
Stop draining fluid when fuel begins to drain out.
1.4
Alliance/Racor Models : Turn the drain plug clockwise to close it.
1.4
DAVCO Models : Close the drain valve. Install and hand-tighten the vent cap.
2.
Inspect the steering components.
2.1
Inspect tie rods, steering arms, and the drag link for signs of looseness (i.e., shiny spots or rust tracks). See Fig. 23.11 .
  • 1. Steering Gear Mounting Bolts
  • 2. Pitman Arm Pinch Bolt Nut
  • 3. Drag Link Nut
Fig. 23.11, Integral Steering Gear Fasteners
2.2
Check the steering gear mounting bolts and pitman arm nut, if equipped, for signs of looseness.
2.3
Check the drag link nuts for missing cotter pins.
2.4
Inspect the steering intermediate shaft and end yokes for excessive looseness or other damage.
NOTICE
Do not drive with a drive belt that is visibly worn or damaged. If it fails, the lack of coolant flow could rapidly cause damage to engine components.
3.
Inspect the serpentine drive belts for signs of glazing, frayed edges, breaks, cracks, or oil contamination.
4.
Check the power steering reservoir fluid level.
4.
The power steering fluid level should be between the MIN COLD mark and the middle mark just above it. If needed, fill the reservoir with automatic transmission fluid that meets Dexron III or TES-389 specifications.
5.
Inspect visible engine wiring for damage or looseness. Check for loose wiring, chafed insulation, and damaged or loose hold-down clamps.

Monthly Post-Trip Inspections and Maintenance

Brake Component Inspection

Walk around the vehicle and inspect brake system components for visible damage.
1.
Inspect all visible brake system components for missing fasteners or signs of looseness, such as rust tracks.
NOTICE
If the external breather tube or breather cap is missing or incorrectly installed, road dirt and debris can adversely affect the operation of the brake chamber. Once inside of the chamber, dirt and debris can cause the internal parts of the chamber to deteriorate faster.
2.
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.
3.
Inspect air brake lines for dents, swelling, kinks, twisting, abrasion, and damage, especially near moving parts.
4.
Inspect flex air lines for deterioration or signs of abrasion.
5.
Inspect for cracked, worn, or oil-contaminated brake linings and brake drums (or rotors).
6.
Check the thickness of the brake linings. Replace 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 Area Inspection

WARNING
When draining the air reservoir, do not look into the air jets or direct them toward anyone. Dirt or sludge particles may be in the airstream and could cause injury.
NOTICE
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.
1.
Drain the brake system air reservoirs (reservoirs with automatic drain valves only).
2.
Inspect the batteries.
WARNING
Battery posts, terminals, and related accessories contain lead and lead compounds, chemicals known to the State of California to cause cancer and reproductive harm. To prevent possible personal injury, always wash your hands after handling battery parts and related accessories.
2.1
Remove the battery box cover and inspect all visible battery cables for loose wiring or damage.
2.2
Check that the battery hold-down is secure.

Engine Compartment Inspection

Tilt the cab. See Chapter 2 for instructions.
1.
Check the hydraulic clutch reservoir, if equipped. If necessary, add DOT 4 brake fluid.
2.
Inspect the radiator and heater hoses, including the clamps and support brackets.
2.1
Inspect the radiator and charge air cooler for damage and accumulated debris. Straighten bent or damaged fins to permit airflow across all areas of the cores.
NOTE: When traveling through areas of high insect concentration, it may be necessary to clean the exterior of the radiator or the charge air cooler core as often as every 200 miles (322 km).
2.2
Make sure the radiator inlet and outlet hoses are pliable and are not cracking or ballooning.
2.3
Make sure the heater hoses are pliable and are not cracking or ballooning.
2.4
Tighten hose clamps as necessary.
IMPORTANT: Do not overtighten hose clamps, as hose life can be adversely affected.
2.5
Ensure hose support brackets are securely fastened. Make sure hoses are not located near sources of wear, abrasion, or high heat.
IMPORTANT: When replacing hoses, install service-type knitted or braided yarn-reinforced neoprene hose. Extended-service-life silicone hoses may also be used. See the Alliance Parts Catalog atwww.alliancebrandparts.comor contact your Freightliner dealer.