Most Common Reasons Cars Fail Roadworthy Inspections
Aug 27, 2025
If you’re planning to sell your vehicle or simply keep it safe and legal on the road, a roadworthy certificate is essential. In Australia, a roadworthy inspection ensures that your car meets minimum safety standards before it can be sold, re-registered, or returned to the road after major repairs. While the process may seem straightforward, many vehicles fail on their first attempt due to avoidable issues.
Understanding the most common reasons cars fail roadworthy inspections can save you time, money, and stress. In the blog, we’ve outlined the typical problems inspectors see and how a qualified mechanic or timely car service can help prevent them.
Worn Tyres
One of the biggest culprits for failed inspections is tyre condition. Tyres are your vehicle’s only point of contact with the road, so inspectors pay close attention to them.
- Low tread depth: In Australia, the minimum legal tread depth is 1.5mm across the tyre surface. Anything below this is considered unsafe and results in an automatic fail.
- Uneven wear: Misaligned wheels, poor inflation, or suspension issues often cause one side of the tyre to wear faster than the other. Even if tread remains in some areas, uneven wear can still cause your car to fail.
If you’re unsure about your tyres, book a quick check with a mechanic before your inspection. Replacing tyres in advance will often be cheaper than paying for a re-test.
Faulty Brakes
Your brakes are arguably the most important safety system in your vehicle, which is why inspectors take them so seriously. Any sign of compromised braking performance will mean you won’t receive a roadworthy certificate.
Common brake-related issues include:
- Worn brake pads or rotors that reduce stopping power.
- Leaking brake fluid, which indicates a compromised hydraulic system.
- Uneven braking, often caused by calliper or disc issues.
A car service that includes a brake inspection can help catch these problems early. If your brakes feel spongy, make noise, or pull the car to one side, get them checked before your inspection date.
Broken or Non-Working Lights
Lights are essential for visibility and communication on the road. It’s surprising how often cars fail roadworthy checks because of something as simple as a blown bulb.
Inspectors check all lights, including:
- Headlights (low and high beam)
- Brake lights (essential for safety)
- Indicators (front, side, and rear)
- Reverse lights (mandatory in many states)
Lights must not only work but also be properly aligned to avoid dazzling other drivers. A quick pre-inspection walkaround (switching on all lights and asking someone to check them) can save you from an unnecessary failure.
Suspension Issues
Suspension plays a huge role in both comfort and safety. If your car feels unstable, bounces excessively, or makes clunking noises over bumps, there may be suspension problems that could stop you from getting a roadworthy certificate.
Common suspension faults include:
- Worn or leaking shock absorbers.
- Damaged struts or springs.
- Deteriorated bushings or mounts.
Suspension issues affect handling, braking, and tyre wear. A mechanic can spot these problems during a standard car service, and it’s worth addressing them early to avoid further damage.
Windscreen Damage
Your windscreen is more than just glass. It’s a key safety component. Inspectors will fail any car that has:
- Cracks or chips in the driver’s line of sight.
- Large fractures that could compromise the structural integrity of the glass.
Even minor chips can spread quickly, especially with changes in temperature or rough roads. Getting chips repaired before your inspection is usually cheaper than replacing the entire windscreen.
Don’t forget your wiper blades. They must be functional and able to clear water effectively. Damaged or ineffective wipers are another common reason for failure.
Steering Problems
Safe steering is essential for maintaining control of your car. During an inspection, the examiner will check for:
- Excessive play in the steering wheel.
- Loose or unresponsive components.
- Leaking or damaged steering racks or pumps.
Any looseness or stiffness in your steering system raises red flags for safety. Regular checks during a car service can keep your steering tight and responsive, ensuring you don’t fail for something that could have been fixed easily.
Fluid Leaks
Finally, fluid leaks are a frequent cause of failed inspections. Even small leaks can indicate larger issues, and inspectors won’t pass a car with visible drips or stains. Common culprits include:
- Oil leaks from the engine or gearbox.
- Coolant leaks, which can lead to overheating.
- Brake fluid leaks, which compromise braking performance.
While a few minor stains might seem harmless, they can point to bigger mechanical problems. Having your mechanic inspect and repair any leaks beforehand is the best way to ensure your vehicle is roadworthy.
How to Avoid Failing a Roadworthy Inspection
The good news is that most of these issues are preventable. Here are some simple steps:
- Schedule regular car service – Preventative maintenance helps catch issues before they become major safety risks.
- Do a pre-inspection check – Walk around your car, check lights, tyre tread, and fluid levels.
- Listen and feel – Pay attention to strange noises, vibrations, or changes in how your car handles.
- Book with a trusted mechanic – A professional can identify and fix problems quickly, saving you from costly re-tests.
Failing a roadworthy inspection is frustrating, but it’s not the end of the world. More importantly, these checks are in place to keep you and others safe on the road. By keeping up with regular car service appointments and addressing small issues before they become big ones, you’ll improve your chances of passing the inspection the first time.
If you’re unsure whether your vehicle is ready for its inspection, visit a trusted mechanic. They’ll ensure your car meets all requirements for a roadworthy certificate and give you peace of mind knowing your vehicle is safe and compliant.
