Pre-MOT Checklist for Lorries: 15 Items to Inspect Before Test

A lorry that passes its annual test first time is rarely lucky. Usually, someone walked around it with a torch and a checklist a fortnight earlier and dealt with the small things while they were still small. A failed test costs a day of downtime, a second test fee and an awkward call to the customer whose delivery is now sitting on a bay. A pre-MOT inspection costs an afternoon. Here is how to spend that afternoon well.

This is a spotting checklist, not a repair manual. Brakes, steering and anything else safety-critical belong with a competent technician.

Start With the Last Test Sheet

Before you crawl under anything, read the paperwork. The most useful document is not the pass certificate, it is the advisory list from the previous annual test and the notes from your own safety inspections. Advisories are not failures, but they mark the places an examiner's attention will go again.

Pull the driver defect reports for the past six months too. A lamp that keeps blowing, a slow air leak that gets topped up and forgotten, a rattle nobody can trace: that is how avoidable failures begin. If the same fault appears on three walkaround sheets and no job card, it needs attention before the test, not after.

The 15-Point Pre-MOT Checklist

Work through this in order. It starts with checks anyone can do and finishes where you need a pit, ramps or a second pair of hands.

1. Lamps and indicators. Headlamps, dip and main beam, indicators, hazards, brake lights, fog lamp, markers and the number plate lamp. Check lenses and tell-tales.
2. Reflectors and conspicuity markings. Correct colour and position, and not cracked, faded or missing.
3. Air build-up and leaks. Warning buzzer working, pressure building as it should, and the system holding pressure with the engine off.
4. Brake components. Pads, discs, drums and actuators; slack adjuster travel; hoses and pipes free of chafing or rubbing.
5. Park brake. Operates cleanly and holds, with a lever or valve that is not sloppy or sticking.
6. Tyres. Tread depth, cuts, bulges, embedded objects, pressures, and matched sizes across an axle. Check inner walls on twin wheels.
7. Wheels and nuts. Cracks, corrosion, stud condition, wheel nut indicators and correct torque.
8. Steering. Play in the wheel and linkage, kingpins, drag link, plus power steering fluid level and leaks.
9. Suspension. Springs, air bags, shock absorbers, U-bolts, hangers and ride height valves.
10. Chassis and underframe. Cracks, heavy corrosion, loose components, security of the battery box and fuel tank.
11. Cab and body. Doors, hinges, latches, mirrors, steps, grab handles, sharp edges and the cab tilt mechanism.
12. Glass and wipers. Chips or cracks in the swept area, blades that clear properly, washers that spray.
13. Seats and belts. Seats that lock in place, belts that retract, buckle and show no fraying or damage.
14. Exhaust, emissions and leaks. Exhaust security, visible smoke, oil or fuel weeps, and warning lamps that stay lit.
15. Speedometer and limiter. Working, correctly set, with plate details matching the vehicle.

Lamps: The Cheapest Failures to Avoid

Lamps fail for boring reasons. A corroded bulb holder. A lens full of water. A trailer lead with a broken pin. Walk the whole combination with someone on the switches rather than trusting a quick glance at dusk.

Park facing a white wall or a window and you will spot more than you expect. Check the forgotten ones too: side markers along the trailer, the number plate lamp, the fog lamp, and the tell-tale on the dash that proves the circuit actually works. If you fit a bulb, test it again after refitting the lens, because a trapped seal will put you back where you started within weeks.

Headlamp aim is worth checking before the test rather than after. A beam pointing at the tarmac is not a catastrophe, but it is still a failure.

Brakes, Tyres and the Underside

Air brakes give you a warning if you listen for it. With the system fully charged and the engine off, a healthy system holds its pressure. One that drops steadily has a leak, and leaks get worse rather than better. Your maintenance provider or workshop manual will tell you the acceptable leak rate for your vehicle, so check against that rather than guessing.

While you are underneath, look at what the examiner will look at: slack adjuster travel, hose condition, corrosion along the chassis rails, and the security of mudguards, spray suppression flaps and side guards. A flap hanging by one bolt is a five-minute fix in your yard and a fail sheet in the test lane.

Tyres get rushed, and twin wheels hide the worst of it. Run your hand around the inner wall of every tyre, including the ones you cannot see from the kerb. A bulge or a deep cut on the inside face is invisible until

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