Chapter 4 Preventive Maintenance Program

Objectives (1 of 2) Explain the characteristics and benefits of a well-planned preventive maintenance program. List and describe the steps of the pre-trip inspection procedure. Describe the criteria for deadlining or out-of- service (OOS) tagging a vehicle. Implement a policy of preventive maintenance scheduling that conforms to federal inspection regulations.

Objectives (2 of 2) Describe inspector qualifications and record- keeping requirements. Select lubricants for the various tasks of preventive maintenance. Describe the operation of on-board chassis systems, both manual and automatic, for vehicle lubrication. Prepare trucks and trailers for cold weather by winterizing.

Preventive Maintenance Advantages –Lower maintenance cost –Maximum vehicle availability –Better fuel economy –Reduced road failures –Better customer relations –Reduced incidence of accidents due to defective equipment –Fewer driver complaints Importance of Records –DOT requirements –Performance –Used to develop maintenance programs –Useful as proof of maintenance during accident investigations

Setting Up a PM Program PM inspections –Schedule “A”; a light inspection taking about 2.5 hours of labor –Schedule “B”; a more detailed inspection taking about 5 hours of labor –Schedule “C”; a more detailed inspection including service and adjustments requiring about one day’s labor –Schedule “D”; a comprehensive inspection and adjustment often including component replacement or rebuilding –Schedule “L”; a chassis lubrication

Driver Inspection Pre-trip and post-trip inspections are spelled out by DOT regulations. The inspection form is usually found on the back of the hours-of-service log.

Inspection Procedure Step 1 Vehicle overview Step 2 Engine compartment Step 3 Inside of cab Step 4 Front of cab Step 5 Left side of cab Step 6 Left fuel tank area Step 7 Left rear tractor Step 8 Left side of trailer Step 9 Rear of trailer Step 10 Right side of trailer Step 11 Right rear tractor Step 12 Right fuel tank Step 13 Right side of cab Step 14 Cab

Deadlining a Vehicle (Out-of-service) Anything mechanical that can either cause or prevent an accident is a safety item (FMCSR part 393).

Caution Do not confuse the out-of-service (OOS) specification with the OEM safe operation limits. –OOS limit indicates that the system has become potentially dangerous.

PM Scheduling (1 of 3)

Shop Talk Remember that if the technician misses something or fails to repair a defect before an inspection, the inspectors may take the vehicle out of service. –That can be costly—in both downtime and fines. –It can also hurt a fleet’s DOT safety rating. –Worse yet, the defect could cause an accident.

Shop Talk It should be noted that off-highway vehicles rarely have odometers. –Most use engine service or the vehicle’s hour meter to measure PM intervals, as opposed to distance traveled. –One current trend bases PM timetabling on the amount of fuel consumed.

PM Scheduling (2 of 3) Federal inspection regulations The following vehicles must be inspected: –Any vehicle involved in interstate commerce with a gross vehicle weight over 10,000 pounds –Any vehicle regardless of weight which is designed to carry more than 15 passengers –Any vehicle, regardless of weight, carrying placarded hazardous materials

PM Scheduling (3 of 3) Record-keeping requirements PM software

Shop Talk When undertaking PM checks and servicing trucks, it is sometimes necessary to raise the cab. –With most hydraulic cab-lift systems, there are two circuits: the push circuit that raises the cab from the lowered position to the desired tilt position, and the pull circuit that brings the cab from a fully tilted position up and over the center. –Remember that in most systems, whenever raising or lowering the cab, stop working the hydraulic pump once the cab goes over center. –The cab falls at a controlled rate and continued pumping could lock up the tilt cylinders.

Lubricants (1 of 8) Engine oilsAdditives –Oxidation inhibitors –Antirust agents –Detergents –Anticorrosion agents –TBN additives

Lubricants (2 of 8) SAE grade of engine oil –See Table 4-3 on page 98 of textbook.

Shop Talk Both the SAE viscosity grade and API (American Petroleum Institute) classification are clearly displayed on the label of any oil container.

Lubricants (3 of 8) Diesel engine oil classifications –The first character describes the type of engine for which the oil is designed. C: compression ignition; for diesel engines S: spark ignition; for gasoline engines G: appropriate for gasoline engines –The second character further describes the oil’s characteristics. Future classifications are added in alphabetical order. CISH CH-4GF-2 CI-4GF-3 PC-10GF-4

Shop Talk Using the incorrect grade or type of oil in an engine can cause a variety of problems. –For example, the wrong viscosity oil can cause either an oil consumption or low oil pressure problem, depending on the weather and driving conditions. –Using an oil with the incorrect service rating can result in inadequate protection for engine bearings and other moving engine parts. –Consult the engine manufacturer’s recommendations to ensure that the engine is using the correct grade and type of oil.

Lubricants (4 of 8) Used oil Gear lubricants –See Table 4-4 on page 100 of the textbook.

Lubricants (5 of 8) Chassis lubricants –See Table 4-5 on page 101 of the textbook.

Lubricants (6 of 8) On-board chassis lubricating system –Manual systems –Automatic chassis lube systems (ACLS)

Lubricants (7 of 8) Properties of greases –See Table 4-6 on page 102 of the textbook.

Lubricants (8 of 8) Trailer lubrication –See Table 4-7 on page 105 of the textbook.

Winterizing (1 of 4) Engine coolant –Inspection –Clean the cooling system –Antifreeze EG PG ELC

Winterizing (2 of 4) Checking coolant condition –Hydrometers –Refractometers –Litmus/chemical tests –Lab sample analysis –Supplemental coolant additive Disposal of antifreeze

Winterizing (3 of 4) Air system Starting aids –Electric block heaters –Fuel-fired heaters –Oil pan heaters –Glow plug systems –Grid heaters –Ether starting systems Cab comforts Batteries and electrical system

Winterizing (4 of 4) Diesel fuel Fuel-water separators General winterizing tips

Warning Avoid using ether with glow plug-equipped engines. On engines with an air pre-heater, consult the engine owner’s manual.

Performing a Lube Job Greasing the chassis Checking fluids

TECHTIP When preparing to perform a lube job, place a few zerk fittings in your pocket before beginning. –Zerk (spring-loaded ball) seals may seize and prevent grease from entering; replace a failed zerk fitting with a new one.

Caution (1 of 2) Some spring hangers are manufactured from cast aluminum alloy: Never apply heat anywhere near cast aluminum suspension components.

Caution (2 of 2) Remember that grease is both difficult to remove and may permanently stain surfaces. –There is probably nothing that will enrage a driver more quickly than grease on any part of a truck chassis other than where it is supposed to be. –Work clean! Use floor mats and change coveralls before driving a vehicle after a lube job.

TECHTIP Remember that a hand-actuated grease gun actually develops higher pressure than an air grease gun and may open a zerk nipple that a pneumatic gun failed to open.

Summary (1 of 3) A preventive maintenance program involves the inspection and servicing of the vehicle as a whole. –The program’s success depends on careful planning. The maintenance program that is most effective is tailored around the needs and experiences of each individual operation. The driver identifies many repairs when performing pre-trip and a post-trip inspections.

Summary (2 of 3) A vehicle considered likely to cause an accident or breakdown because of mechanical conditions or improper loading should be taken out of service. It is the fleet’s responsibility to ensure that all personnel performing annual inspections are qualified. Maintenance managers and truck technicians are expected to be computer literate because service tracking is computerized.

Summary (3 of 3) Proper lubrication is important in reducing wear and preventing premature failure of truck components. Winterizing a heavy-duty truck is an important part of any PM program. Performing a lube job properly is a requirement of an entry level truck technician from day one on the job.