You have to be cautious when assuming that your brakes only squeak when you first start driving. The noise from road and engine sounds can easily drown out the sound of squeaking brakes when you’re driving at higher speeds (unless you have an electric vehicle).
To get straight to the point, this article will provide you with information on why moisture can cause brake squeaking in the morning or when the brakes haven’t warmed up yet. However, this is not a common issue and is usually only observed in very humid environments.
While the problems listed below can point you in the right direction of why your brakes squeak when they’re warmed up, it is important not to rule out other potential issues until you have them inspected.
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What Causes Brakes to Squeak When You Start Driving?
The most common causes of brake squeaking are usually related to a failure in the brake system or something coming into contact with the brakes that shouldn’t be there. The following items are commonly found when examining this type of issue:
1. Worn Brake Discs
When brake discs wear down, the pads, which are still in good condition, catch on the wear lip around the edge of the rotor. This rubbing between the two metal components produces a squeaking noise. As the brakes heat up, the squeaking usually subsides since both the pads and the rotor are made of metal-based compounds.
To fix this issue, you either need to replace the pads and rotors or have the surface of the rotor skimmed to eliminate the lip. However, this is only possible if they are still within the wear tolerance.
2. Sticking Brake Caliper
A sticking brake caliper occurs when the brake pads remain engaged with the rotor, either fully or partially. Although you can still drive with this issue, you will hear a squeaking noise as the rotor is forced to rotate with the wheel. When the brakes become hot, the caliper releases itself, allowing you to drive normally.
The usual causes of this problem are a faulty caliper piston seal or a collapsed brake hose. The correct course of action is to replace the faulty component. However, in some cases, taking the caliper off, bleeding the brake fluid, and winding it back so that the piston seal fully retracts can resolve the issue.
3. Damaged/Bent Backing Plate
Behind the brake rotors, there is a shield known as the backing plate, which prevents debris, dirt, and water from coming into contact with the brake discs. If debris in the road damages the backing plate, it can touch the rotor while driving, resulting in a metal-on-metal squeaking noise. The noise may disappear after driving a few miles due to the heat generated, which causes the backing plate to melt and no longer scrape against the rotor.
It is easy to manipulate the backing plate with your hands or a screwdriver to move it away from the brakes. In rare cases, it may need to be removed and replaced.
4. Dirt or Debris Stuck in the Brakes
Similar to the backing plate issue, dirt and debris can become lodged between the brake pads and the rotor, initially causing a squeak. This is often caused by small rocks getting stuck. As the wheel rotates, the stone wears away, and the squeak stops. However, the rock can then reposition itself and start squeaking again.
To resolve this issue, you will need to disassemble the brakes and remove the object completely. In some cases, using a screwdriver to free the object caught between the backing plate and the rotor may be sufficient.
5. Moisture
Moisture on the brake rotors can lead to surface rust, especially overnight in cold and damp conditions. After a rainy night, you may notice surface rust when looking through the car rims. As you drive, this rust can cause a squeak, but it usually subsides after a few minutes.
Why Do My Brakes Squeak Only in the Morning?
Brake squeaking in the morning is a common occurrence, and the cause is simple: condensation. Overnight, condensation forms on the surface of the brake rotor and pads, creating a small amount of surface rust. When you apply the brakes a couple of times, the surface rust is removed, but it can be annoying until it disappears.
Do not attempt to remove the rust from the brake disk surface using substances like WD-40, as it will not have the desired effect. It can actually damage the brake pads, causing them to overheat and become brittle.
If you’re concerned, you can use a brake and clutch cleaner along with some blue roll to clean the brake disks. These products will not damage the brakes. However, a simpler solution is to drive the car and apply the brakes firmly a few times to clear any rust from the disks.
Is Brake Squealing Until Warmed Up Normal?
In most cases, brake squealing is not normal and should not be entirely ignored unless it is confirmed that there is nothing wrong with the brakes. Having a brake wear indicator installed in most modern vehicles may lead some people to think that as long as the brake pad wear indicator light is not illuminated, there is no issue. However, this assumption alone should not be the basis for ignoring the problem.
Once you have confirmed that there are no issues with the brakes and it is solely a moisture-related problem, it is generally safe to drive.
Why Do My Brakes Squeak When I Drive Slowly?
Brake squeaking when driving slowly or even in reverse is typically caused by the brake pad wear indicators catching on the disk or the brake pads being completely worn out and coming into contact with the lip on the rotor. Sometimes, this squeaking noise can only be heard at low speeds, especially when the noise persists even after the brakes have warmed up.
Summary
When you experience brake squeaking when you first start driving, it should not be dismissed or assumed to be a minor issue without inspecting the brakes. Moisture on the brake rotor may seem like the cause, but worn pads catching on the lip of a worn rotor can produce similar issues, with the squeaking only stopping once the brakes have warmed up. To be certain, it is advisable to have your brakes inspected by a mechanic. Some garages even offer free brake inspections if you search for them.
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