What are brake pads and how do they work?
Brake pads are metal pads on which a layer of abrasive materialcalled "friction" is applied. When they are pressed by the brake shoes or calipers against the disc, they generate a great frictional force. This force is what slows and stops the vehicle in motion.
The composition of brake pads varies from one model to another depending on how they are used. The brake pads of sports cars have a very aggressive composition that favours very fast braking, but they wear out very quickly. On the contrary, the brake pads of small cars like your mother's Lancia Ypsilon have a resistant composition to last over time, while ensuring less reactive braking.
Due to the constant use of the brakes, sooner or later every car will require the replacement of worn brake pads. If they are not replaced, it will not only make driving less pleasant, but may also lead to safety problems and make it impossible to control the car.
1st symptom of worn brake pads - squealing when braking
One of the clearest signs that it's time for a brake inspection is hearing a high-pitched sound when braking.
This is due to the fact that the pads have become worn or damaged and therefore create an uneven friction surface. In extreme cases, the squealing is due to the fact that we have completely exhausted the layer of friction material.
When the brake pedal is pressed, the disc is squeezed not by the friction material but by the metal base of the brake pads. In addition to being very dangerous to drive in these conditions, we risk consuming and damaging the disc itself.
Remember that changing the brake pads is a small expense, changing the whole disc can cost up to 4 times more. As soon as we hear a clear squeal when braking we should deduce that the worn brake pads should be changed to ensure safe driving and to safeguard the much more expensive brake calipers.
2nd symptom of worn brake pads - brake pad warning light is on.
Not much to do. If the brake pad warning light comes on, it means that the control unit is detecting that the brake pads are numbered.
In fact, many cars are equipped with a sensor that, when it makes contact with the metal of the pad, is able to detect the level of remaining abrasive layer.
When this layer reaches the minimum safe threshold, the brake pad warning light comes on, clearly indicating the presence of worn brake pads. When the brake pad warning light comes on, we can change the brake pads as soon as possible.
Check out our article on what to do when the brake pad warning light comes on.
3rd symptom of worn brake pads - "spongy" braking.
If you press your foot on the brake pedal and it feels harder or "spongier" than normal as if you have foam-soled shoes, chances are you have worn brake pads. This type of sensation also manifests itself when you feel like you've reached the end of the pedal without being able to stop the car.
Don't worry, you can still use the car, but you'll need a lot more force to apply the brake. This can make braking in emergency conditions very difficult and make driving dangerous. In the city, for example, you can't stop your car when a pedestrian suddenly crosses the road.
The best thing to do is to go to a mechanic as soon as possible and have your brakes checked to make sure you are driving safely.
4th symptom of worn brake pads - burning smell
If you start to smell a strong chemical burning smell while driving, it's likely that one of your brake pads is worn out or the caliper is stuck.
Stop the car immediately and check that you haven't left the handbrake on. Then check to see if you see smoke coming from one of the wheels.
If so, one of the brake calipers is stuck and it is dangerous to continue driving.
The best thing to do is to find a mechanic in the area and get assistance on the spot. The repair takes a matter of minutes and allows you to continue driving calmly and without being a danger to other road users. The mechanic will simply remove the wheel and remove the locked brake caliper. He will then proceed to unlock it and replace the worn brake pads.
5th symptom of worn brake pads - unresponsive braking
If the brake pads are very worn, braking will be much less reactive and immediate.
In other words, you will have to brake harder and longer to stop your car.
This is obviously a problem because the car becomes uncontrollable and you risk causing a car accident.
So you have to change worn brake pads as soon as possible.
Non-reactive braking could also be caused by a loss of pressure in the brake fluid system. In this case, when you get to the mechanic, it will be helpful to let him know and ask for the brake fluid level to be checked as well. An abnormal level or a broken brake fluid line can be clear evidence of a problem with the brake system.
6° Symptom of worn brake pads - brake pedal vibration
When you put your foot on the brake pedal, do you feel vibrations or pulsations?
If the answer is YES, then there is a problem with the brake pads or the disc itself.
This vibration is in fact due to incorrect contact between the brake pads, shoes and disc, and is a sure sign of brake system problems or worn pads.
As soon as you get to the mechanic, he will have to check both the brake system and the mechanical connections of the pedal. Vibrations can be caused by a simple loose bolt or a missing rivet. When it comes to mechanics, unfortunately anything is possible and therefore you need to make the necessary checks to get back on the road safely.
7th symptom of worn brake pads - the car pulls to one side
If the car pulls to one side while braking, there may be a problem with the car, probably the brake system.
If one of the brake pads is much more worn than the opposite wheel, the car will tend to pull to the side of the less worn pad.
This is because the less worn pad generates more friction, resulting in more and faster locking of the respective wheel but not the opposite one.
Therefore, it is crucial to ensure safe driving that the brake system is inspected immediately and worn brake pads are replaced. It is best to replace both brake pads and not just the most worn one. This is because by putting a new pad on one side only and leaving the more worn pad on the other, we have the same problem we are trying to solve.
A car pulling more to one side can also be a symptom of a locked brake caliper. There may be a mechanical defect or damage to the brake fluid system that causes the brakes to lock up.
Another cause of the car rolling to one side is a problem or leak in the brake fluid line. A small leak is enough to make braking uneven and cause the car to brake more on one side than the other.