When some part of the car does not work properly, the first sign that is usually noticed is a strange noise. In the case of brakes, the most frequent sound is that annoying chirp capable of attracting the eyes of everyone who walks down the street at that time.
The strange thing about this type of car brake noise is that they can be a symptom of a large number of problems. From the most insignificant, to serious breakdowns or wear, for which it will be necessary to take immediate action. Therefore, here we explain the possible causes and how to eliminate them.
The first thing you have to be clear about before getting down to work is that the brakes are a crucial part of car safety. That's why always must be treated with the utmost professionalism and rigor. Needless to say, that is what you will find in a trusted workshop, where they will be able to solve any problem related to the brakes.
That said, it is also true that you can do a visual inspection yourself, in addition to following some simple steps to fix some brake problems. If you know them, you will be able to save money or, at least, you will know if you are being taken for a ride in some dubious workshop.
Brake pads
One of the most common sources of brake squeal is usually the brake pads. Remember that they are responsible for stopping the rotation of the wheels and, through them, a vehicle of one, two or more tons. Therefore, it is not surprising that noises are generated for various reasons. These are the most common:
- spent pills: If its thickness decreases enough, some metal parts may rub against the disc and generate a very loud noise. The pads will need to be changed immediately.
- poor quality pills: If you skimp too much on the brake pads you buy, it can become noticeable with screeching or other abnormal noises. Especially since they do not include some fastening pins or other parts, and you have to reuse the old ones.
- Pickups that are slightly different in shape than the ones you removed: Sometimes a small difference in their shape causes the pads to rub differently against the rotor. If it already has the typical step due to the use of the previous pickup and the new one touches it excessively, it usually results in excessive noise or even a squeak.
- crystallized pills: crystallization occurs when the tablets are overheated. This can happen due to excessive use of the brakes, which has exceeded its tolerance levels (be careful again with poor quality pads) or due to a defective disc. Crystallized tablets are easily recognized because they have a much glossier surface than those in good condition.
- Uneven brake pad wear: within different types of brakes that there are, some tend to wear out the pads inside more. When there is already a lot of difference between both sides, it can translate into greater vibrations of the set and, consequently, the happy screeching of the brakes.
brake calipers
There are several components in the calipers that can be the cause of abnormal brake noises. Mainly because they have moving parts that require lubrication and proper maintenance. This is what may be causing noises:
- If the clips that hold the pills they are rusty and without lubrication strange noises will be heard. So it is good to clean them well and lubricate them, for which the liquid manufactured by WD-40 or similar brands is very useful.
- If they break clips that help pills separate when we do not brake, the noise will be heard even if we are not braking.
- Lube Free Slide Pins: you have to remove them and put synthetic grease on them so that they perform their function well. It is also advisable to check the dust covers they have, so that they do not lose their grease and that dirt or water does not enter them. Below we explain the complete process and add a video so you can see an example of how it is done.
freno discos
The source of the brake squeal can also be found in the discs. These are the most common problems with these parts:
- worn discs: although they are made of a very hard metal, the discs also end up wearing out brake after brake. When their thickness has decreased a lot, you will notice a step near the edge that can cause noise. This is because said step rubs against the pad and generates an unpleasant screeching noise. In the following article we tell you when they should be changed:
- Scratched or cracked discs: If the discs have been scratched by dirt, gravel, or anything hard enough to scratch them, their friction against the pads will cause vibrations. This can translate into the squeak we are trying to eliminate.
- misplaced disc: When changing discs, it is very important that there is no dirt or impurity on the surface on which they are placed. If this is not taken into account, the disc can be poorly seated and, although the deviation is not visible to the naked eye, it could be heard when braking. Keep in mind that the speed at which the wheel spins can be very high and the vibrations can be heard as a high-pitched sound.
hydraulic brake system
Un insufficient braking Hydraulic system problems are also a likely cause of squealing brakes. If there is a caliper that is not squeezing the disc hard enough with the brake fluid, all it will do is rub and grind. The ones that are actually stopping the car with the other wheels whose brakes are working normally.
To detect this, you can lift the car and, while pressing the brake, try to move the wheel with your hands. If you don't have anyone to help you, you can use a stick or other solid object propped up against the seat to keep the pedal tight.
How to get rid of squealing brakes
Once you have an idea of the origin of the squealing brakes, it is recommended to follow the following steps to find a quick solution to the problem:
- First of all, it is important to make a list of some elements that may be necessary to carry out a good inspection and provide a concrete solution to the problem. You should have on hand:
- un jack to lift the carAlthough it's also advisable to use trestles to keep it upright for safety. There are some available, although you can also opt for those that can withstand... 3 tonnes to insure.
- a liquid brake cleaner: such as Liqui Moly or the one from , although there are more brands.
- Anti-Squeak Brake Spray: those of Liqui Moly o WD-40 They are ok, although you have more options.
- wrenches for nuts of different sizes. A tool box for car It will be very useful and they are not expensive.
And without the problem requires replacement of parts:
-
- brake pads
- brake discs
- brake fluid
- a rubber hammer.
- Once you have what you need, it's time to get to work: you start by lifting the wheel where the noise comes from with the cat and its respective reinforcement is put on it to avoid accidents (such as the aforementioned easels). Keeping a block of wood at the proper height is also an option to provide additional security. In that case do not remove the cat.
- Take out the wheel, as they are covering the assembly of the disc brake and that is the area where the screeching is created. Start by visually inspecting the pads and discs for any signs of wear. Check the discs (also called rotors) for scarring, wear, or warping in any way. The screeches can come from the small slots. Also, warped discs may be the problem you're looking for. In this case, you will have to change them.
- Since you are at this point spray and clean the rotor and the brake caliper to remove accumulated dust. This must be done before starting to separate the brake mechanism.
- Check the interior to check the condition of the brake pads. Try to detect if they are worn and, therefore, are the cause of the noise. It can be seen with the naked eye by removing the wheel or through the rim if there is enough clearance.
- If they are worn, pull the caliper off the rotor and remove the two Brake Pad that are inside the caliper. Replace them with a new pair, so you can remove the screeching brakes. You must clean the inside of the caliper very well with the brake cleaner and a rag, before inserting the new pads. We recommend the following article to know what this process consists of:
- See if the bolts are still well protected by their respective caps and dust covers. If someone can help you, have them step on the brake while you watch to see that the pads snap back into place when the pedal is released.
- Use an Allen wrench to separate the shoe from the disc brake rotor. It is necessary to reach brake caliper with the Allen key, so that you have to loosen and remove two screws that are there. After removing the screws clean them very well, then apply lubricant WD-40 Spray with a rag. Cleaning and lubrication of the brake system is an efficient way to get rid of squealing in brakes. Brake Pad or on the rotors. In this video you can see how they do it: