How PM B differs from PM A
In a tiered program, PM A is the most frequent and lightest service. PM B happens less often and covers more. A common pattern is that PM B includes everything on the PM A checklist, then adds items that do not need attention at every visit. The exact contents vary between fleets, vehicle types and engine makers, so the checklist is the real definition. See PM A service.
Items a PM B often adds
The fleet program and maker schedules decide the list. Items commonly moved to PM B include:
- Fuel filters and, where scheduled, air filter replacement.
- A fuller brake inspection with measurements on every wheel position.
- Steering and suspension components checked for play, wear and damage.
- Driveline, U-joints and wheel ends.
- Cooling system condition and coolant test.
- Batteries, cables and charging system test.
- Fifth wheel, kingpin and coupling devices on tractors and trailers.
Linking PM B to the annual inspection
Some fleets line up a PM B with the periodic inspection required by 49 CFR 396.17, because both need the truck in the shop with a qualified person looking at the same systems. The annual inspection has its own standard, the minimum periodic inspection standards in Appendix A to Part 396, and its own report. If the two are combined, keep both records complete. See annual inspection.
Records
Under 49 CFR 396.3, carriers must keep records of inspection, repairs and maintenance that show the date and nature of the work. A PM B record should show the unit, mileage or hours, each item checked, measurements, parts used and defects found, with defects carried to repair lines that the customer approves.
Pricing note
Because PM B takes longer than PM A, shops usually price it separately. Publish what each level includes so the fleet can compare quotes fairly. See PM service cost for a semi truck.
Related: PM C service, PM service.
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