The Daily Pre-Start Inspection Checklist That Keeps Your Machine Running

I watched a 793 haul truck lose its right rear brake line on a downhill ramp in Nevada. The operator had skipped his pre-start walk-around because he was running late. That brake line was chafed against a loose retainer clip for three shifts. When it let go, the truck had no brakes on that side. The driver managed to get it to the dump point using the retarder and parking brake, but it cost the site a week of downtime and a $90,000 repair bill. All because someone didn't use a daily pre-start inspection checklist.

A **daily pre-start inspection checklist** is the cheapest insurance you can buy. I spent 30 years as a Caterpillar field service engineer across six continents, and I can tell you that 90% of sudden failures I saw had early warning signs that a decent pre-start would have caught. This isn't about ticking boxes to satisfy a safety officer—it's about making sure you get home with all your fingers and the machine stays productive.

Let me walk you through the checklist I developed over decades of field work. I've refined it on everything from D11 dozers to 797F haul trucks, and it works equally well on your mid-size excavator or wheel loader.

The Walk-Around: Look Before You Touch

Start your **daily pre-start inspection checklist** with a slow walk around the machine. Don't just glance—stop at every corner. I'm looking for anything that doesn't belong: oil drips, coolant stains, broken lights, loose bolts, vandalism, or debris that shouldn't be there.

Pay special attention to:

• **Tires and rims** – check for cuts, bulges, low pressure (use a gauge if you have one; don't just kick the tire). On large mining trucks, a tire failure at speed can kill.
• **Undercarriage (for track machines)** – look for missing track shoes, loose bolts, leaking final drive seals. A thrown track in the pit is a bad day.
• **Hydraulic hoses** – run your hand along the routing (yes, physically touch them). Feel for chafing, bubbles, or heat. A hydraulic hose burst at 5,000 psi will cut through steel—and flesh.
• **Fluid leaks** – any puddle under the machine is a problem. Color tells you what: red (transmission/hydraulic), green or gold (engine coolant), black (engine oil), clear (fuel). Don't ignore the small puddle—it's always bigger than you think.

Field Lesson: On an iron ore site in Western Australia, a loader operator told me his machine felt sluggish. I asked about his pre-start. He said, "I always check the oil." But he never looked underneath. We found a hydraulic hose the size of your thumb that was weeping—not spraying, just weeping. That small leak was draining the tank slowly. By the time it became a performance issue, the pump was already damaged. Three shifts later, the pump failed catastrophically. A full **daily pre-start inspection checklist** would have caught that weep two weeks earlier.

Fluid Checks: The Basics You Can't Skip

Once the walk-around is done, pop the hood or access panels. This is where most checklists start, but I want you to do the walk-around first. Why? Because a fluid leak you saw on the ground gives you context for the dipstick reading.

Check these in this order:

• **Engine oil** – let the machine sit for 10 minutes after shutdown (or check before starting cold). Wipe the dipstick, reinsert, then read. Fill to the full mark—never overfill. A overfilled crankcase can foam and cause bearing failure.
• **Coolant level** – only check when the system is cool (or use a pressure-rated coolant recovery tank). Never open a hot radiator cap—I've seen the steam burns.
• **Hydraulic oil** – same procedure as engine oil. Know your machine's sight glass location; not all have dipsticks.
• **Transmission / differential / final drives** – these are often overlooked. Check the sight glasses or level plugs. Low gear oil will eat bearings in a hurry.
• **Fuel/water separator** – drain any water from the bowl. Water in fuel kills injectors and pumps.

Safety Alert: On a copper mine in Chile, I saw a technician open a hot hydraulic tank to check fluid. The pressurized oil burst out and ignited on the exhaust. He survived with burns over 40% of his body. Always follow the manufacturer's procedure. If the machine is hot and you're unsure, wait.

Going Through the Cab: Controls and Indicators

Now get in the cab. Before you crank the starter, go through the **daily pre-start inspection checklist** for the operator environment:

• **Seat belt** – check it's clean, retracts fully, and latch works. I don't care if you're only moving the machine 50 feet—wear it.
• **Mirrors** – adjust them. Clean any mud or dust.
• **Warning lights and gauges** – turn the key to ON (don't start). All warning lights should illuminate briefly, then go out. If any stay on, you have a problem. Note the dash display for any active fault codes.
• **Controls** – move each control through its full range while the engine is off. Feel for binding, looseness, or unusual resistance. This is especially important for hydraulic controls and brakes.
• **Brakes** – test the parking brake. Apply it, release it, listen for air leaks on brake systems. If you have air brakes, let the system build pressure before releasing the parking brake.

Once you're satisfied, start the engine. Listen for unusual sounds: sharp knocks, whines, screeches. Watch the gauges as they stabilize. Oil pressure should come up within seconds. If it doesn't, shut it down immediately.

The First Five Minutes: A Second Inspection

After starting, let the machine idle for a few minutes—longer if ambient temperature is below freezing. During this warm-up, do a second round of checks:

• **Air system** – with air brakes, listen for leaks (hissing). Watch the air pressure gauge—it should build to cut-out pressure and then hold. If it drops more than a few psi in 5 minutes with the engine off and brakes released, you have a leak.
• **Hydraulic system** – cycle each function (lift, tilt, bucket, etc.) but don't load it. Watch for jerky movements, abnormal noise, or slow response.
• **Steering** – turn the wheels lock to lock. Any hesitation suggests low hydraulic flow or air in the system.
• **Transmission** – shift through each gear or direction (neutral to forward to reverse, etc.) while stationary. Clunking or delayed engagement means problems.
• **Final drive noise** – on track machines, drive forward and reverse a few feet. Listen for clicking or popping from the final drives.

Field Lesson: On a D10T dozer in Colorado, the operator told me he heard a "faint click" during his pre-start transmission check. I had him run it again. That click was one broken tooth on the sun gear. We pulled the final drive and replaced the gear before it grenaded and took out the entire planetary set. The repair cost $4,000 instead of $18,000. A six-second listen saved $14,000.

The Daily Log: Document What You Found

A **daily pre-start inspection checklist** is only as good as the record you keep. Grab a log book or use a digital form. Write down:

• Machine hours and date
• Any fluid added (type and amount)
• Any leaks, cracks, or damage found
• Any dash codes or warning lights
• Actions taken (e.g., tightened loose bolt, reported to shop)

Don't assume the next operator or the shop will see what you saw. I've traced countless failures back to an operator who said, "I meant to tell someone about that drip," but never wrote it down. If it's not documented, it didn't happen.

Final Thought: Make It a Habit

The **daily pre-start inspection checklist** I've outlined here takes about 10 minutes for a typical machine—maybe 15 for a large mining truck. That's less time than a coffee break. I've seen it prevent everything from a $90,000 brake line failure to a $400,000 engine rebuild. And more importantly, I've seen it prevent injuries and deaths.

I've seen this go wrong. Here's how you avoid it: commit to the checklist every shift. Print this out, laminate it, put it in the cab. Teach your operators why each step matters—not just how to do it. When they understand the field behind the lesson, they'll never skip it again.

Now go do your pre-start. Your machine—and your crew—depend on it.