8 Common Issues That Can Cause a Roadworthy Failure
When preparing to sell, transfer or re-register a vehicle in Queensland, a roadworthy certificate is required. This certificate ensures your car meets the minimum safety standards necessary to be driven legally on public roads. But what causes a car to fail a roadworthy check? The answer usually lies in a handful of preventable issues that, if left unchecked, can lead to inspection failures.
In this blog, we’ll explore some of the most common roadworthy certificate fail reasons and provide practical tips on how to avoid them.
1. Tyre Wear & Tread Depth: Why Bald Tyres Are a Common Fail
Tyres are your vehicle’s only connection with the road, making their condition critical to handling, braking, and overall safety. During a roadworthy inspection, tyres are one of the first things checked, and any sign of wear or damage could be enough to fail the vehicle. Worn tyres reduce grip, increase stopping distances, and are especially dangerous in wet conditions where aquaplaning becomes more likely.
- Tread depth must be at least 1.5mm across the full width of each tyre.
- Bald spots, exposed cords or uneven wear patterns can lead to automatic failure.
- Damage such as cracks, bulges, or cuts to the sidewall also renders a tyre unroadworthy.
Rotating your tyres regularly, maintaining correct pressure, and aligning your wheels can help preserve tyre life and performance.
2. Brake System Defects: When Stopping Power Fails Safety Standards
Brakes are a critical safety feature and a key focus in any roadworthy inspection. Even subtle issues in the system can result in a failure.
- Worn brake pads or rotors below legal thickness.
- Leaking brake fluid or low reservoir levels.
- A spongy or slow-responding brake pedal.
- Noisy braking due to scoring or warped discs.
A brake check during routine servicing ensures these issues are caught early, before they affect stopping power or inspection results.
3. Light & Signal Faults: The Visibility Rule That Trips Up Many Drivers
Functional lights aren’t just a legal requirement—they’re essential for safe driving in all conditions. Faulty lights are a simple but common reason for failing a roadworthy test.
- Headlights, taillights, indicators, and brake lights must be fully operational.
- Cracked, fogged, or discoloured lenses reduce visibility and effectiveness.
- Incorrect bulb colours or mismatched lights are also flagged.
Regularly checking your lights is quick and easy. Activate each function one at a time and walk around your vehicle to ensure they are all bright, consistent, and correctly coloured. If anything appears out of the ordinary, replacing or repairing it before your inspection is best.
4. Suspension & Steering Play: More Than Just a Bumpy Ride
Your suspension and steering systems keep your vehicle stable and responsive. Worn or loose components in these areas compromise control, especially at speed or under braking.
- Excessive steering wheel movement or poor responsiveness.
- Uneven ride height or excessive bouncing.
- Worn shock absorbers, leaking struts, or broken coil springs.
- Damaged or perished rubber bushings or ball joints.
If your vehicle pulls to one side or rattles over bumps, have the suspension inspected before heading to a roadworthy check.
5. Windscreen and Wiper Condition: Clear Vision, Clear Pass
Visibility is another key concern. Damage to the windscreen or ineffective wipers can compromise your view and lead to failure.
- Cracks or chips in the driver’s field of vision are automatic fails.
- Scratched or clouded glass can reduce clarity and is assessed on a case-by-case basis.
- Wiper blades must effectively clear water without streaks or squeaking.
- Washer jets should spray correctly and be filled with fluid.
A clear, unobstructed windscreen and properly functioning wipers are vital during adverse weather conditions—and for passing inspection.
6. Exhaust System Leaks: When the Problem Isn’t Just Noise
A leaking or damaged exhaust system increases noise levels, releases dangerous fumes into the cabin, or fails emissions standards.
- Holes, cracks, or rust in the exhaust pipes or muffler.
- Loose mounting brackets or excessive movement.
- Audible leaks, especially under acceleration.
- Signs of exhaust fumes entering the cabin space.
These issues are roadworthy concerns and pose health and safety risks. Prompt repair is essential.
7. Seatbelt Functionality: The Most Overlooked Lifesaver
Seatbelts might seem straightforward, but their condition and performance are scrutinised closely during inspections. They must function correctly to ensure passenger safety.
- Cuts, frays, or visible wear on the belt material.
- Buckles that don’t click securely or release smoothly.
- Belts that don’t retract fully or evenly.
- Improperly mounted or missing anchor points.
All seating positions must have compliant seatbelts. Before inspection, check them individually, not just the driver’s side.
8. Oil Leaks & Engine Condition: The Hidden Signs That Can Ground You
Engine leaks, particularly oil and fluid leaks, are another common cause of roadworthy failures. While minor seepage might be acceptable, active drips or stains indicate a more serious issue.
- Oil visibly dripping from the sump, rocker cover, or oil filter area.
- Pooled fluid beneath the engine bay or on the driveway.
- Signs of fluid on suspension components or underbody.
- Strong burning smell or smoke from the engine bay.
A mechanic can diagnose the source and severity of a leak—early attention can prevent costly repairs and a failed certificate.
Keep Your Vehicle Roadworthy with Regular Maintenance
Most of the issues that lead to roadworthy failures aren’t sudden. They’re often the result of postponed maintenance, overlooked warning signs, or minor wear and tear left unattended. Addressing these concerns early not only helps you pass the roadworthy inspection but also extends your vehicle’s lifespan and keeps you and others safe on the road.
At A.M.D. Automotive Services, we understand the importance of a smooth inspection process. Our team offers comprehensive pre-roadworthy checks, professional advice, and repairs to help you meet the standards without stress. Whether you’re preparing to sell your car, transfer ownership, or re-register, we’ll ensure your vehicle is ready for inspection.
Give us a call or visit our contact page to book your roadworthy certificate in Mackay today. Let us help you stay safe, compliant and confident on the road.