Daily Pretrip Inspection and Maintenance Procedures

wv dm 12.02.001

Whenever equipment requires adjustment, replacement, repair, addition of lubricants, or a change of lubricants, see the Walk-In Van Chassis Workshop Manual for repair procedures and specifications. Specific references to the manual will be found where appropriate.

  1. Drain manually drained air reservoirs (that are not equipped with automatic drain valves).
    Water and oil normally enter the air reservoir in the form of vapor because of the heat generated during compression. After the water and oil condense, drain the resulting emulsion as follows:
    1. Open the wet tank valve. The drain cock or pull chain drain is located on the forward end of the supply air reservoir, which is connected directly to the air compressor. Block the valve open.

      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.
      1. Exhaust the remaining air and moisture from the system by opening the drain cocks on the bottoms of the remaining air reservoirs. Block the valves open.
      2. Water and oil emulsion often form pockets that will not drain while compressed air is in the reservoirs. Because of these pockets, leave the valves blocked open during the first part of the pretrip inspection.
    2. Check the coolant level in the surge tank.
      If the coolant is low, Slowly add a 50/50 mixture of antifreeze and water to the surge tank; no more than 3.0 gallons per minute (gpm). Fill to the top of the surge tank. For approved coolants, refer to the coolant label on the vehicle or the engine manufacturer's service literature. Coolant used must be compatible with engine manufacturer’s coolant specifications. For Cummins approved coolants, refer to the engine manufacturer's service literature at Cummins Online athttps://www.cummins.com/support/manuals or scan the QR code. See figure . For Detroit™ engine service literature, refer to the Detroit Diesel link on the DTNA TechLit website https://www.dtnatechlit.com/portal-public or scan the QR code. See figure . Fill the surge tank with coolant to the MAX line when the tank is cool. If the surge tank was empty, start the engine after refilling, then check the level again when the engine is at operating temperature. See figure .

      Fig. 1, Cummins QR Code

      Fig. 2, TechLit QR Code

      Fig. 3, Surge Tank Fill Cap

      3. 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. Inspect the radiator and charge air cooler.
      1. Inspect the radiator and charge air cooler for clogged fins. Use compressed air or water directed from the fan side of the core to backflush any material restricting airflow.
      2. 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 (320 km).
        1. Also inspect and clean the condenser. If clogged, the condenser can restrict airflow through the radiator.
        2. Check the radiator for leaks. If leaks are found, have the radiator repaired or replaced. Take the vehicle to an authorized Freightliner dealer for assistance.
      3. Inspect the engine for fuel, oil, and coolant leaks. On vehicles equipped with a compressed natural gas (CNG) engine, use a natural gas detector to check for natural gas leaks.
        Correct any leaks found.
      4. Inspect the air intake system for leaks or damage.

        Notice: Failure to maintain a sealed air intake system could allow entry of dirt and contaminants into the engine. This could adversely affect engine performance and result in engine damage.
          1. Check the intake-air restriction indicator, if so equipped.
          2. Replace the primary filter element in the air cleaner when filter restriction reaches 25 inH 2O for Cummins engines or 15 inH 2O for GM engines. See Group 09 of the Walk-In Van Chassis Workshop Manual for filter element replacement instructions, or take the vehicle to an authorized Freightliner dealer. See figure and figure .

            Note: To replace the filter, the canister must be replaced.

            Fig. 4, Farr Air Cleaner Filter Element

            1. Primary Filter Element

            Fig. 5, Donaldson Air Cleaner Filter Element

            Note: After replacing the filter element, reset the restriction indicator by pressing the rubber reset button, if so equipped.
            1. Inspect the secondary or safety filter element in the air cleaner when replacing the primary element, and replace it when clogged or dirty. This element should be replaced with every third primary element replacement.
            2. Check the engine air intake piping from the air cleaner to the engine intake. Inspect the piping for loose connections, cracks, torn or collapsed hoses, punctures, and other damage. Tighten loose connections, and have damaged components replaced. Make sure the piping system is airtight so that all intake air passes through the air cleaner.
          3. 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.
              1. Park the vehicle on a level surface. Allow several minutes for the oil to drain back into the oil pan to ensure an accurate reading.

                Note: Follow the engine manufacturer's guidelines for engine shutdown time requirements prior to checking the oil level.
                1. Pull out the dipstick and clean it with a paper towel or cloth, then push the dipstick back in all the way. Remove it again, keeping the tip down, and check the oil level.
                2. If the oil is below the cross-hatched area, or the add mark, at the tip of the dipstick, add at least one quart (liter) of the recommended oil. See figure for diesel engines and figure for gasoline and liquid propane gas (LPG) engines.
                  For diesel engines that comply with EPA07 or newer regulations, use CJ-4 engine oil with less than 1% sulfated ash.
                  For gasoline and LPG engines, use SAE 5W–30 oil that meets GM standard GM6094M and has the American Petroleum Institute (API) symbol. Do not use SAE 10W–40 or 20W–50.

                  Fig. 6, Oil Dipstick (diesel engine)

                  Note: Oil should be within the cross-hatched area of the dipstick.

                  Fig. 7, Oil Dipstick (gasoline and propane engines)

                2. Notice: Failure to use the recommended oil can result in engine or aftertreatment component damage and will void the warranty.

              2. Check the oil level in the automatic transmission.

                Note: The fluid must be warm to ensure an accurate check. The fluid level rises as temperature increases.
                  With the vehicle on a level surface, check the oil level in the transmission using one of the following procedures:
                  Hot Check

                  • Operate the transmission in a Drive (D) range until normal operating temperature, 160 to 200°F (71 to 93°C), is reached.

                  • Park the vehicle. Shift to Neutral (N) and apply the parking brake. Let the engine run at idle.

                  • Wipe the dipstick clean and check the fluid level. A safe operating level is any level within the HOT-run (upper) band on the dipstick. See figure .

                    • Hot-Run Band

                    • Cold-Run Band

                    Fig. 8, Automatic Transmission Dipstick Markings

                  • If the fluid is not within this range, add or drain fluid as needed to bring the level to the top of the HOT-run band. See the Walk-In Van Chassis Maintenance Manual for fluid types and capacities.

                  1. Important: Do not drain the fuel/water separator completely. Drain no more than three tablespoons of fluid at a time.

                1. Check the fuel/water separator for contaminants and leaks.

                  2. Important: When draining fluid from a fuel/water separator, drain the fluid into an appropriate container and dispose of it properly. Many states now issue fines for draining fuel/water separators on the ground. On all types of separators, stop draining fluid when you see fuel come out of the separator drain valve.

                2. Inspect the fuel tanks, fuel lines, and connections for leaks.
                  On vehicles equipped with a compressed natural gas (CNG) engine, inspect the fuel tanks, fuel regulators, fuel filters, and the fuel lines. Use a natural gas detector to check for any leaks, or spray the components with a soap-and-water solution and check for bubbles.
                  1. Check that the fuel tanks are secured to their mounting brackets and that the mounting brackets are secured to the frame.
                  2. Replace leaking fuel tanks.
                  3. If lines or connections are leaking, have them repaired or replaced.
                    For repair and/or replacement procedures, see Group 47 of the Walk-In Van Chassis Workshop Manual , or take the vehicle in to an authorized Freightliner dealer.
                  4. If equipped with fuel tank shutoff valves, be sure the valves are fully open.

                  3. Warning: Never operate the engine with the fuel tank shutoff valves partly closed. This could damage the fuel pump, causing sudden loss of engine power, possibly resulting in serious personal injury due to reduced vehicle control.

                3. Check the fuel level in the fuel tank(s).
                  On vehicles equipped with a diesel engine be sure that the fuel cap vent area is clean. Check the fuel/water separator (if so equipped) for leaks and, if needed, prime the fuel tank system.
                  On vehicles equipped with a compressed natural gas (CNG) engine, check the pressure gauge mounted in the fuel fill box to determine the amount of fuel in the fuel tanks.

                  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.

                    Important: Use only ultralow-sulfur diesel (ULSD) fuel with 15 ppm sulfur content or less, based on ASTM D2622 test procedure. Failure to use ultralow-sulfur diesel fuels may void the warranty on emissions components.
                      1. To keep condensation to a minimum, fill diesel fuel tanks at the end of each day, but not to more than 95 percent of liquid capacity. Select the proper grade of fuel, as specified by the engine manufacturer.

                        Warning: 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.
                        1. Always strain or filter diesel fuel before putting it into the tanks. This will lengthen the life of the engine fuel filter and reduce the chances of dirt entering the engine.
                      2. Inspect the front and rear suspension components, including springs, spring hangers, shocks, and suspension brackets.
                        1. Check for broken spring leaves, loose U-bolts, cracks in the suspension brackets, and loose fasteners in the spring hangers and shackles.
                        2. Inspect the shock absorbers for loose fasteners and leaks.
                        3. Tighten all loose fasteners and have any components replaced that are worn, cracked, or otherwise damaged.
                        4. On vehicles with air suspensions, check for leaks. Check air suspension components for cuts and bulges.

                        3. Warning: Do not replace individual leaves of a damaged front or rear suspension leaf spring assembly; replace the complete spring assembly. Visible damage, such as cracks or breaks, to one leaf causes hidden damage to other leaves. Replacement of only the visibly damaged part(s) is no assurance that the spring is safe. If cracks or breaks exist on front spring assemblies in either of the two top leaves, a loss of vehicle control could occur. Failure to replace a damaged spring assembly could cause an accident resulting in serious personal injury or property damage.

                      3. Check the oil- and air-pressure warning systems.
                        When the engine is started, oil- and air-pressure warnings will come on until the oil and air pressure rise above a preset minimum. After starting the engine, make sure the oil- and air-pressure warning systems are operating and that the buzzer stops sounding when the preset minimum is reached.
                        1. If the warning systems do not come on when the ignition is turned on, have the systems repaired.
                        2. If the air pressure in both systems is above the preset minimum when the engine is started, test the low air pressure system by lowering the pressure to below this range, or until the warning system comes on.

                        4. Note: The air pressure in both the primary and secondary air reservoir systems must be above 65 psi (448 kPa) on most vehicles.

                      4. Make sure that the electric horn works.
                        If a horn is not working, have it replaced before trip departure.
                      5. Make sure that the electric horn works. Check the high and low beams of the headlights. Clean the windshield, side, and rear windows (if equipped) with a long-handled or telescoping window cleaning device and standard cleaning solutions. Stand only on the ground, on a stepladder, or an elevated walkway. The vehicle entry/exit steps and handholds are not designed for this purpose. The tires, fenders, engine, and other under-hood components do not have adequate gripping surfaces and handholds.

                        Danger: Do not loosen or remove the parking brake clamp ring for any purpose. See figure . The parking/emergency brake section of the brake chamber is not intended to be serviced. Serious injury or death may result from sudden release of the power spring.

                        Before doing any repairs or adjustments on a service/parking brake chamber, read the applicable warnings and instructions in Group 42 of the Walk-In Van Chassis Workshop Manual .
                        1. Inspect the air brake chamber and the air brake chamber pushrods. See figure .

                          • Do not remove this clamp ring.

                          1. MGM TR-T (TR Series) Brake Chamber shown

                          Fig. 9, Parking Brake Chamber Clamp

                        2. Inspect the slack adjusters.
                          1. Meritor Slack Adjusters: Check the boot for cuts, tears, or other damage. Have it replaced if necessary.
                          2. Inspect the slack adjuster boot for cuts or tears. If the boot is damaged, have it replaced. See figure .

                            1. 7/16-inch Adjusting Nut

                            2. Grease Fitting

                            3. Boot

                            4. Link

                            5. Brake Chamber Piston Rod

                            6. Clevis

                            7. 1/2-inch Clevis Pin

                            8. 1/4-inch Clevis Pin

                            9. Grease Relief Opening

                            10. Slack Adjuster Spline

                            Fig. 10, Automatic Slack Adjuster (typical)

                        3. Check tire inflation pressures using an accurate tire pressure gauge.
                          Tires should be checked when cool. For inflation pressures and maximum loads (per tire) see the tire manufacturer's guidelines.
                          1. Be sure valve stem caps are on every tire and that they are screwed on finger-tight.
                          2. Inflate the tires to the applicable pressures if needed.
                          3. If a tire has been run flat or underinflated, check for possible wheel or tire damage before adding air.
                            Moisture inside a tire can result in body ply separation or a sidewall rupture. During tire inflation, compressed air reservoirs and lines must be kept dry. Use well maintained inline moisture traps and service them regularly.

                          4. Warning: Do not operate the vehicle with underinflated or overinflated tires. Incorrect inflation can stress the tires and make the tires and wheels susceptible to damage, possibly leading to wheel or tire failure and loss of vehicle control, resulting in serious personal injury or death.

                          Important: The load and cold inflation pressure must not exceed the wheel manufacturer's recommendations, even though the tire may be approved for a higher load inflation. Some wheels are stamped with a maximum load and maximum cold inflation rating. If they are not stamped, consult the wheel manufacturer for the correct tire inflation pressure for the vehicle load. If the load exceeds the maximum wheel capacity, the load must be adjusted or reduced.

                          Important: Low-rolling resistance (LRR) tires minimize wasted energy as a tire rolls, thereby decreasing rolling effort and improving fuel efficiency. If tire replacement is necessary, replacement tires must meet or exceed the rolling resistance of the originally installed tires in order to maintain compliance with greenhouse gas and fuel efficiency regulations.

                          Contact your tire manufacturer/supplier to determine the rolling resistance of the originally installed tires. Visitwww.epa.gov/smartwayfor additional information and resources.

                        4. Inspect each tire for wear, bulges, cracks, cuts, penetrations, and oil contamination. 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.
                          1. Check 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.
                          2. Inspect each tire for bulges, cracks, cuts, and penetrations.
                          3. Inspect each tire for oil contamination. Fuel, oil, gasoline, and other petroleum derivatives, if allowed to contact the tires, will soften the rubber and destroy the tire.
                        5. Check the wheel nuts for indications of looseness. Examine each wheel component.
                          1. Remove all dirt and foreign material from the assembly. Dirt or rust streaks from the stud holes, metal buildup around stud holes, or out-of-round or worn stud holes may be caused by loose wheel nuts. See figure and figure .

                            Fig. 11, Dirt and Rust Streaks from the Stud Holes

                            Fig. 12, Worn Stud Holes

                          2. Examine the wheel components (including studs and nuts) for cracks or other damage.
                            See Group 33 or Group 35 of the Walk-In Van Chassis Workshop Manual for service procedures on the studs and hubs, and see Group 40 in the same manual for wheel and tire servicing, or take the vehicle to an authorized Freightliner dealer.

                            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.
                            1. Make sure all wheel nuts are tightened 450 to 500 lbf·ft (610 to 678 N·m) for Accuride wheels with unlubricated threads. Use the tightening pattern in figure for 10-hole wheels and figure for 8-hole wheels. See Group 40 of the Walk-In Van Chassis Workshop Manual.

                              Fig. 13, Tightening Pattern, 10-Hole Wheels

                              Fig. 14, Tightening Pattern, 8-Hole Wheels

                            3. Notice: 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. Use the recommended torque values and follow the proper tightening sequence.

                            Note: Vehicles operating under severe or adverse conditions should be checked more frequently.

                          3. Check the air brake system for proper operation.
                            1. Check the air governor cut-in and cut-out pressures as follows:
                              Run the engine at fast idle. The air governor should cut out the air compressor at approximately 120 psi (827 kPa). With the engine idling, apply the brake pedal several times. The air governor should cut in the air compressor at approximately 100 psi (689 kPa). If the air governor does not cut in and out as described above, it must be adjusted to these specifications. If the air governor cannot be adjusted or repaired, replace it before operating the vehicle.
                            2. Check the air pressure buildup times as follows:
                              With the air system fully charged to 120 psi (827 kPa), make one full brake application and note the air pressure reading on the gauge. Continue to reduce the air pressure by moderate brake applications to a maximum of 90 psi (620 kPa), then run the engine at governed rpm. If the time required to raise the air pressure to 120 psi (827 kPa) (from the pressure noted after one brake application) is more than 30 seconds, eliminate any leaks or replace the air compressor before operating the vehicle.
                            3. Check the air pressure reserve as follows:
                              With the air system fully charged to 120 psi (827 kPa), stop the engine and note the air pressure. Then make one full brake application and observe the pressure drop. If it drops more than 25 psi (172 kPa), all areas of leakage must be eliminated before operating the vehicle.
                            4. Check the air leakage in the system as follows:
                              With the parking brake (spring brake) applied, the transmission out of gear, and the tires chocked, charge the air system until cut-out pressure of 120 psi (827 kPa) is reached.
                              With the service brakes released, shut down the engine, wait 1 minute and note the air pressure gauge reading. Observe the air pressure drop in psi (kPa) per minute.
                              Charge the air system until cut-out pressure of 120 psi (827 kPa) is reached. With the parking brakes released and the service brake applied, shut down the engine, wait 1 minute and note the air pressure gauge reading. Observe the air pressure drop in psi (kPa) per minute.
                              If leakage exceeds the limits shown in table , repair all areas of leakage before driving the vehicle.

                              Table 13, Maximum Allowable Service Brake Leakage

                              Maximum Allowable Service Brake Leakage

                              Brakes Released

                              Brakes Applied

                              2 psi/min. (14 kPa)

                              3 psi/min. (21 kPa)

                                Table 13, Maximum Allowable Service Brake Leakage

                            5. Test the parking brake on a 20 percent grade.
                              Apply the hand brake with the vehicle on a 20 percent grade (or as steep a grade that the vehicle may normally be parked on). The ramp surface should be made of Portland cement or equivalent. If the parking brake does not hold the vehicle, repair the parking brake system.
                            6. Check the operation of the Bendix® Hydro-Max brake booster, as follows.
                              1. With ignition off, depress the brake pedal and listen for the back-up motor to engage. Also, note that the pedal force relieves; the pedal should depress easily.
                              2. With the ignition off, engine running, parking brake released, ensure that the BRAKE warning indicator light is not on. This is a dual indicator and indicates that the parking brake is set, and warns if there is a hydro-max failure other than loss of back-up motor power.
                            7. Inspect the engine and chassis wiring.
                              Check for loose wiring, chafed insulation, and damaged or loose hold-down clamps. Tighten loose wires or hold-down clamps; replace damaged wiring or clamps.
                            8. Test the service brakes.
                              When starting to move the vehicle and before picking up speed, test the brakes with the foot pedal and parking brake control valve (yellow knob) to be sure they will bring the vehicle to a safe stop.
                            Note:
                            Parent topic: Pre- and Post-Trip Inspections and Maintenance
                            Document Number: 0000071825
                            Manual Publication Date: 2024-03-26
                            Topic Publication Date: 2024-03-26