Trailer inspection – rules, checklist and common defects
A roadworthiness inspection covers all safety-relevant components on your trailer. Preparing properly in advance saves time, avoids re-inspections, and ensures everything works as it should. Inspection rules, intervals, and requirements vary by country – always check the regulations that apply in your region.
What is checked during a trailer inspection?
In most countries, a trailer inspection covers the following areas:
– Lighting and electrical system
– Brake system and overrun brake
– Tyres, rims, and tyre pressure
– Wheel bearings and running gear
– Coupling and safety devices
– Frame condition and corrosion
Checklist – what to check before the inspection
Lighting: Check that all rear lights, indicators, and brake lights work correctly. Inspect the wiring and connectors for damage or poor contact. See the trailer lighting guide for more detail.
Brakes: Test the brakes and overrun brake for smooth, even operation. Check the brake cables for stiffness or fraying and inspect the brake shoes for wear.
Tyres and pressure: Check tyres for damage, cracks, or uneven wear. Verify that tyre pressure matches the manufacturer’s specification. See the guide on trailer tyre pressure.
Wheels and bearings: Spin each wheel by hand and check for play, noise, or roughness. Worn wheel bearings should be replaced before the inspection.
Coupling: Check the coupling head for play, wear, or damage. Verify that the breakaway cable is correctly fitted and in good condition.
Frame: Inspect the frame and load-bearing parts for rust, cracks, or visible damage.
Most common defects found at trailer inspections
– Faulty lighting or electrical connection problems
– Worn or unevenly adjusted brakes
– Incorrect tyre pressure or damaged tyres
– Play in wheel bearings or hub components
– Corrosion on structural parts
– Worn or damaged coupling head or safety devices
Most of these can be avoided by replacing wear parts in good time. Components such as brake shoes, brake cables, and overrun brakes are wear items that should be inspected regularly.
Typical symptoms and their likely causes
Brakes overheat – often caused by worn or incorrectly adjusted brake shoes
Trailer jerks when braking – often a faulty overrun damper; see the guide on replacing the overrun damper
Lighting failure – usually a wiring or connector issue
Play in wheel – indicates worn wheel bearings or hub components
Tips for a successful inspection
– Test all lighting and electrical connections in advance
– Check the brake system and all moving parts
– Verify tyre condition and pressure
– Check mechanical components for play or wear
– Fix minor defects early – do not leave them until inspection day
Summary
Most inspection failures come down to lighting, brakes, tyres, and coupling condition. With the right preparation and timely replacement of worn parts, passing a trailer inspection is straightforward. Inspection rules and intervals vary by country – always check what applies in your region before the inspection date.