Understanding Handbrake Failures in Your MOT Test

The MOT test is a crucial annual inspection designed to ensure your vehicle is safe and roadworthy. One of the most common reasons for a vehicle to fail its MOT is an issue with the braking system, and specifically, the handbrake, or parking brake as it's also known. A properly functioning handbrake is not just about preventing your car from rolling away when parked; it's a vital part of your vehicle's overall braking capability, particularly in emergency situations. This article delves into what happens if your handbrake fails an MOT, the reasons behind such failures, and what steps you can take to rectify the problem.

Why is the Handbrake So Important for the MOT?

The handbrake plays a significant role in the MOT test because it assesses your vehicle's ability to hold itself stationary on a gradient. This is typically tested on a rolling road (dynamometer). The tester will apply the handbrake with a specific force and measure how much braking effort is generated. If the handbrake doesn't apply enough force to prevent the vehicle from moving, or if it's binding, uneven, or has excessive travel, it will result in a dangerous fault and an immediate MOT failure.

Common Reasons for Handbrake Failure

Several factors can contribute to a handbrake failing its MOT. Understanding these common culprits can help you identify potential issues before your test:

1. Wear and Tear on Brake Pads and Shoes

Over time, the brake pads (for disc brakes) or brake shoes (for drum brakes) that your handbrake system operates can wear down. This is particularly true for rear brakes, which often incorporate the handbrake mechanism. As these components wear, they require more lever or pedal travel to achieve the same braking force, eventually becoming ineffective. This is a natural process of wear and tear, but it's essential to have them inspected and replaced when necessary.

2. Stretched or Damaged Cables

The handbrake system relies on cables to transmit the force from the handbrake lever or pedal to the brake calipers or drums. These cables can stretch over time due to constant tension and use. They can also become corroded, seized, or physically damaged. If a cable is stretched, it will mean more travel is needed before the brakes engage. If a cable is seized, it might prevent the handbrake from releasing fully (leading to binding) or from engaging properly.

3. Issues with Brake Calipers or Wheel Cylinders

In vehicles with disc brakes, the handbrake often operates a small mechanism within the brake caliper that applies pressure to the brake disc. These mechanisms can seize or become contaminated with dirt and debris, reducing their effectiveness. For vehicles with drum brakes, the handbrake usually operates an internal lever that pushes the brake shoes outwards. These levers can also seize or become corroded, leading to a failure. Leaking wheel cylinders or brake fluid can also compromise the system's performance.

4. Incorrect Adjustment

Even if all the components are in good condition, an incorrectly adjusted handbrake will likely fail the MOT. The handbrake needs to be adjusted precisely to ensure it engages effectively without being too tight (which can cause binding and excessive wear). Adjustments are usually made at the cable itself or at the brake mechanism.

5. Binding Handbrake

A binding handbrake is one that doesn't fully release, causing the brakes to remain partially applied. This can lead to overheating, premature wear of brake components, and a significant reduction in fuel efficiency. A binding handbrake will also fail the MOT, often due to the tester detecting the drag or if it causes excessive heat during the brake test.

What Happens if Your Handbrake Fails the MOT?

If your handbrake fails the MOT, your vehicle will be issued with a refusal of an MOT certificate. The reasons for the failure will be clearly listed on the MOT test report. Your vehicle is considered unroadworthy, and you should not drive it unless you are taking it directly to a garage for repairs. Driving a vehicle that has failed its MOT can lead to penalties, including fines and points on your driving licence, especially if it's stopped by the police.

How to Get Your Handbrake Fixed

The first step is to take your vehicle to a qualified mechanic or garage. They will be able to diagnose the exact cause of the handbrake failure. The repair process will depend on the identified problem:

• Component Replacement: If brake pads, shoes, or cables are worn or damaged, they will need to be replaced.
• Adjustment: If the issue is simply a matter of incorrect adjustment, the mechanic can recalibrate the handbrake system.
• Brake Caliper/Cylinder Repair or Replacement: If the calipers or wheel cylinders are seized or damaged, they may need to be repaired (if possible) or replaced.
• Cleaning and Lubrication: In some cases, seized components can be freed up with thorough cleaning and lubrication, though replacement is often a more robust solution.

Once the repairs are completed, your vehicle will need to undergo a partial re-test of the braking system to confirm that the handbrake now meets the required standards. If the garage that performed the repairs is an authorised MOT test centre, they may be able to conduct this partial re-test on-site.

Preventative Measures and Maintenance

To avoid the stress and expense of a handbrake failure, regular maintenance is key:

• Regular Checks: Pay attention to how your handbrake feels. If it seems to require more effort or travel than usual, get it checked. Listen for any unusual noises when applying or releasing it.
• Periodic Adjustments: Have your handbrake adjusted periodically, especially if you notice any changes in its performance.
• Brake System Servicing: Ensure your entire braking system is serviced regularly as part of your vehicle's routine maintenance schedule. This includes checking brake fluid levels and the condition of brake lines.
• Parking Habits: While not a direct cause of failure, always ensure you engage your handbrake firmly when parking on a slope, and consider leaving the car in gear (or 'Park' for automatics) as an extra precaution.

Frequently Asked Questions (FAQs)

Q1: Can I drive my car with a failed handbrake after the MOT?

No, you should not drive your car if it has failed its MOT due to a handbrake issue, unless you are driving it directly to a garage for repairs. Driving an unroadworthy vehicle is illegal and dangerous.

Q2: How much does it typically cost to fix a failed handbrake?

The cost can vary significantly depending on the nature of the fault. Simple adjustments might only cost a small labour fee, while replacing worn cables, brake shoes, or calipers can range from £100 to £300 or more per axle, plus labour. It's best to get a quote from your mechanic.

Q3: What is the difference between a handbrake and a foot brake?

The handbrake (parking brake) is primarily used to keep the vehicle stationary when parked and can act as a secondary braking system in an emergency. The foot brake (service brake) is the primary braking system used for slowing down and stopping the vehicle during normal driving.

Q4: Can a binding handbrake fail an MOT?

Yes, absolutely. A binding handbrake is a dangerous fault as it can lead to overheating of the brakes, reduced fuel efficiency, and potentially spontaneous braking. It will result in an MOT failure.

Q5: How can I check my handbrake at home?

You can perform a simple check by parking your car on a moderate hill (ensure it's safe to do so). Engage the handbrake firmly and see if the car remains stationary. You can also check for excessive travel in the handbrake lever or pedal. However, a proper MOT test involves more rigorous checks, including measuring braking force.

Conclusion

A failed handbrake during an MOT test is a common but serious issue that needs prompt attention. By understanding the potential causes and performing regular checks and maintenance, you can significantly reduce the chances of your vehicle failing its MOT for this reason. Ensuring your handbrake is in good working order is crucial for your safety, the safety of others, and for maintaining your vehicle's roadworthiness.

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