Construction equipment management software › Heavy equipment maintenance schedule
Heavy equipment maintenance schedule: what happens at 250, 500, 1,000 and 2,000 hours
Most heavy equipment follows a four-step service ladder: 250 hours (engine oil and filter, grease, an oil sample), 500 hours (adds hydraulic, transmission and air filters), 1,000 hours (adds transmission and axle oil, a coolant sample) and 2,000 hours (adds secondary and cab air filters, and on some machines hydraulic oil). Each has a calendar limit too; your manual sets the exact list.
The ladder, level by level
The table below is a Cat dealer's planned maintenance levels for a backhoe loader (Ziegler Cat's preventive maintenance booklet). Each level includes everything in the levels below it. Other machines and makers use the same four marks with their own items.
| Level | Every | New at this level |
|---|---|---|
| PM1 | 250 hours or 3 months | Check all fluid levels, engine noise and smoke, gauges and controls; engine oil sample; change engine oil and filter; check fan pulleys and belts; replace secondary and in-line fuel filters; grease every point |
| PM2 | 500 hours or 3 months | Oil samples from transmission, hydraulics and differentials; replace hydraulic and transmission oil filters and the primary air filter; cut filters open to look for metal; change the fuel-water separator; drain water from the fuel tank |
| PM3 | 1,000 hours or 6 months | Coolant sample; clean the fuel-tank cap; inspect the rollover protective structure (ROPS); change transmission oil and front and rear differential oil |
| PM4 | 2,000 hours or a year | Replace the secondary air filter and cab air filters; inspect cooling hoses and lines |
The same booklet's dozer plan follows the same marks and adds final drive oil. Hydraulic oil is where machines differ most. Cat's operation and maintenance manual for the D3K, D4K and D5K dozers sets it at every 2,000 service hours or 1 year, and allows 4,000 hours or 2 years if the oil is sampled every 500 hours or 3 months (the manual's 2,000-hour procedure, as transcribed by MaintainX). Between services, the operator's daily walk-around covers fluids, leaks, grease points and tracks or tires.
Which level is due at which mark
Take the biggest step that divides the hour mark: 2,000, 4,000 and 6,000 are PM4; 1,000, 3,000 and 5,000 are PM3; 500, 1,500 and 2,500 are PM2; every other multiple of 250 is PM1. So a machine at 3,500 hours gets a PM2, and at 4,000 the full PM4.
Hours or months, whichever comes first
Every level has a calendar limit too. A machine that works 15 hours a week takes about 17 weeks to run 250 hours, past the 3-month limit on PM1, so for that machine the calendar sets the schedule. Oil ages and condensation builds even when a machine sits. Seasonal fleets catch this at spring start-up: a machine parked for the winter is due by date, whatever its meter says.
A worked schedule for five machines
| Machine | Hours today | Hours a week | Next mark | Level | Hours left | Weeks left |
|---|---|---|---|---|---|---|
| Mini excavator | 486 | 25 | 500 | PM2 | 14 | 0.6 |
| Excavator | 1,962 | 40 | 2,000 | PM4 | 38 | 1.0 |
| Skid steer | 1,190 | 35 | 1,250 | PM1 | 60 | 1.7 |
| Wheel loader | 3,940 | 30 | 4,000 | PM4 | 60 | 2.0 |
| Dozer | 2,710 | 15 | 2,750 | PM1 | 40 | 2.7 |
Two PM4s land within two weeks of each other, so order both kits now and book the excavator's first. The mini excavator is due this week, and the dozer's last service date matters as much as its hours: at 15 hours a week, its 3-month limit may come before 2,750.
Keeping it from slipping
- Get the hours weekly. Telematics does it by itself; otherwise someone reads the meter. A schedule built on month-old hours is a guess.
- Warn early. 50 hours ahead gives a 40-hour-a-week machine more than a week to order parts and book the shop.
- Record the reading at service in the maintenance log, and keep the ladder on its fixed marks.
Any maintenance tool does this arithmetic for you. In Dozer, a photo of the hour meter gives the hours and the next standard service, and machines within 50 hours of service are flagged; the shop work itself (parts, labor, work orders) needs a shop system. Dozer Machines The maintenance software guide compares those.
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