Car Brake Problems: 7 Warning Signs You Shouldn’t Ignore
A spongy pedal, pulling, grabbing, unusual noises or vibration can all point to a developing brake problem. Bendix explains seven warning signs and what may be causing them.
The Bendix brake range includes pads and disc rotors for passenger cars, European vehicles, 4WDs, light-commercial vehicles and performance applications.
Brakes are at their best when they are boring. You press the pedal, the vehicle slows in a straight line and nobody spills the coffee.
Add a heavily loaded 4WD, a caravan and a long downhill run, however, and even a relatively minor braking problem can become rather more exciting than anyone had planned.
Regular servicing should provide trouble-free braking between workshop visits, but components can wear faster than expected because of driving style, heavy loads, towing conditions or the vehicle’s operating environment. Services can also be missed and mechanical components occasionally fail.
Fortunately, a braking system will often provide some warning before matters become truly serious. The trick is recognising what the vehicle is trying to tell you.
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Low or spongy brake pedal
If the brake pedal feels soft, spongy or travels unusually close to the floor, there may be air trapped in the hydraulic system. This can happen if the brakes were not properly bled after pads, components or brake fluid were replaced.
Low brake fluid may also indicate worn brake pads or, more seriously, a leak somewhere in the system. Simply topping up the reservoir without identifying why the level has fallen is not a proper diagnosis.
Brake fluid is hygroscopic, meaning it absorbs moisture over time. Moisture can enter through hoses, seals and the reservoir vent, gradually reducing the fluid’s effectiveness and lowering its boiling point. Under hard or prolonged braking, contaminated fluid can contribute to a soft pedal and reduced braking performance.
A pedal that suddenly sinks towards the floor demands immediate attention. Find somewhere safe to stop and arrange for the vehicle to be inspected rather than continuing in the hope that it will somehow fix itself.
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Excessive brake pedal effort
Needing unusually heavy pedal pressure to slow the vehicle can have several causes.
One possibility is glazed brake pads. Glazing occurs when excessive heat hardens and polishes the friction material, leaving a smooth, glass-like surface that cannot bite effectively against the rotor.
Other potential causes include badly worn pads, a faulty brake booster, a vacuum-system problem or caliper pistons and slides that are seized or require attention.
Whatever the cause, standing harder on the pedal is not a long-term repair strategy. It is merely your right leg attempting to compensate for a mechanical problem.
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Brake drag
Brake drag occurs when one or more brakes fail to release completely. The vehicle may feel sluggish, require more accelerator input or appear reluctant to roll freely.
The affected wheel may also become excessively hot and produce the unmistakable smell of overheated brakes.
Possible causes include seized caliper pistons or slides, incorrectly adjusted drum brakes, damaged return springs, a sticking parking-brake mechanism, distorted components or a blocked master-cylinder compensating port. A damaged or internally collapsed brake hose can also retain hydraulic pressure after the pedal has been released.
Brake drag increases fuel consumption, accelerates pad and rotor wear and can generate a dangerous amount of heat. If a wheel is smoking or extremely hot, stop safely and do not touch it. Arrange professional assistance.
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Vehicle pulling to one side
If the vehicle pulls sharply to one side when the brakes are applied, the brakes may not be producing equal force on both sides.
Contaminated pads or linings, mismatched components, incorrect caliper or pad alignment, a seized caliper piston or sticking slides can all cause brake pull. Tyre, steering and suspension problems can produce similar symptoms, so a proper inspection is essential.
A vehicle that changes direction whenever the brake pedal is pressed is not displaying personality. It is announcing a fault.
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Brakes grabbing
Brake grab occurs when the brakes apply too aggressively with very little pedal pressure, making smooth stops difficult.
Contamination from brake fluid, grease or other substances can change the friction characteristics of the pads or linings. Misaligned calipers, loose mounting bolts, seized caliper pistons and sticking slides may also cause grabbing.
Kinked, pinched or internally damaged brake hoses can trap pressure in the hydraulic system, causing a brake to remain partially applied or engage with more force than expected.
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Squealing, grinding or rattling noises
Persistent squealing, screeching, grinding, groaning or rattling should never be drowned out by turning up the radio.
These noises can indicate worn or damaged pads, loose hardware, incorrect caliper alignment, glazing, contamination or excessive rotor runout. A harsh metallic grinding noise may mean the friction material has worn away, allowing metal components to contact the rotor.
Some brake compounds may occasionally produce a light squeal, particularly when cold or wet, but a new, persistent or worsening noise deserves investigation.
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Vibration or pedal pulsation
A brake pedal that pulses, or a steering wheel that vibrates when braking, can indicate disc thickness variation.
This occurs when the rotor is no longer presenting a consistent thickness to the pads as it turns. Lateral runout can contribute to the problem and may result from debris or corrosion between the hub and rotor, damaged wheel studs, incorrect installation or uneven wheel-nut torque.
The result is an alternating braking force that can be felt through the pedal, steering wheel or vehicle body.
This should not be confused with the rapid pedal pulsation produced when the anti-lock braking system operates during an emergency stop. ABS pulsation is normal while the system is actively preventing wheel lock-up. Regular vibration during ordinary braking is not.
Seven warning signs that may indicate a developing brake problem, including a spongy pedal, excessive pedal effort, brake drag, pulling, grabbing, noise and vibration.
What should you do if the brakes feel different?
Any noticeable deterioration in braking performance should be investigated promptly by a qualified mechanic.
If the pedal sinks towards the floor, braking performance drops substantially, the vehicle pulls violently, a warning light remains illuminated or there is grinding, smoke or a strong burning smell, stop somewhere safe and have the vehicle transported to a workshop.
For towing vehicles, it is also worth noting when the problem occurs. If braking feels normal when driving solo but changes with the caravan or trailer connected, the trailer brakes, electrical connections and brake-controller settings should be inspected as well.
At the heart of the upgrade are Bendix Ultimate 4WD pads and high-carbon disc rotors, selected to provide consistent braking performance under demanding touring and working condition
Matching the brake components to the vehicle
Bendix offers several brake-pad and rotor ranges for different vehicles and operating conditions.
Its General CT™ pads and rotors are intended for passenger cars in everyday use, with General CT rotors also suitable for pairing with Bendix 4WD/SUV™ brake pads.
For European vehicles, Bendix Euro+™ pads and rotors are developed as original-equipment replacements while producing reduced brake dust to help keep wheels cleaner.
More demanding applications require components selected for the work the vehicle is actually doing. Bendix Heavy Duty™ pads cater for light-commercial vehicles and other vehicles operating under higher loads.
For 4WDs regularly carrying equipment, towing caravans or operating in demanding conditions, the Ultimate 4WD™ range includes pads, rotors and brake-upgrade kits. Bendix also offers Ultimate+™ pads and rotors for sports and performance vehicles requiring increased braking performance.
The broad Bendix range allows workshops to source matched components from a single manufacturer. More importantly, it allows the braking package to be selected based on the vehicle, its load, and how it is used.
The correct brake pad is not simply the one that fits in the calliper. It is the one suited to the job being asked of it, particularly when that job includes several tonnes of touring equipment, a caravan and a mountain range between you and the next coffee stop.
