Brake pad ignition is not uncommon in automotive practice, even if the vehicle shows no signs of serious malfunction. The causes of ignition of the pads will become clear after we understand the principle of the brake system. And after figuring out the causes, let’s talk about how to eliminate them.
How the brake system works
Before proceeding to the disassembly of such a problem as brake pad fire, it is necessary to get a general idea of the principle of operation of such a system. In any vehicle, the assembly consists of discs (or drums), as well as pads, which are responsible for the mechanical deceleration of the “iron horse”. Pressing the pedal, the motorist shifts the piston in the key cylinder, after which the working substance, moving along the lines, activates the cylinders. The latter ensure the clamping of pads with a special agent to the drums or discs, thus ensuring a gradual reduction in speed.
In addition, the complex is equipped with a vacuum booster, minimizing the negative pressure on the pedal, and a special expansion tank for the working fluid. The current systems have auxiliary electronic sensors, such as ABS. This is a specialized electronic complex that prevents the wheels from blocking during sudden deceleration.
Brakes in modern car models are characterized by particular reliability. But they are still vulnerable to all kinds of malfunctions. In addition, their individual parts are consumable and require timely replacement. The rest need quality diagnostics and maintenance.
What are the main causes of overheated pads?
Malfunctions of the braking system occur when the disks are distorted or the pads are worn down. To overheat mechanisms lead to excessive load during friction due to frequent operation. We shall single out several main reasons, which may cause brake pads’ ignition:
The car is equipped with different types of power units
Throughout its history, the car has been equipped with different types of powertrains, while the braking system has remained the same. Any global intervention in the under-hood with a change of the engine configuration has a negative impact on the brakes.
The owner prefers an aggressive driving style
The car owner prefers an aggressive driving style with continuous speeding up and down, shifting between lanes and other manipulations, affecting the braking system. Naturally, this is not the mode of operation recommended by vehicle manufacturers.
Among them – sudden braking at high speed, long downhill slope, braking with a heavy loaded trailer, long-lasting towing, etc.
These problems also occur when driving on bumpy and winding roads, where you frequently have to slow down when entering a curve or going down a mountain. Under the influence of high temperatures the discs are melted and lose their performance. Under critical conditions, the components of the braking system can heat up to 350-600 degrees. But if we are talking about a short-term overheating, quality components can normally withstand it.
But new parts require proper rollback in a delicate mode. As the experts say, it is recommended to overcome 500-1000 km so that the pads adapted for further operation. If you miss such a point, the mechanism can not withstand, due to which there will be ignition of the paint on its plate.
Naturally, in such circumstances will have to use a fire extinguisher or improvised means for extinguishing. But it is not so easy to find the ignition of pads while driving. But the hearth can set fire to the brake hoses, creating an emergency situation.
There are other troubles as well. If they add a lot of lithol to the guide dusters during maintenance of the brake system in the car repair shop, it can ignite under the influence of the rising temperature.
The situation looks even more deplorable with budget components. Not only are they vulnerable to combustion during braking, but also to destruction. The friction mixture can not cope with the load in the form of 5 sharp brakes, and the protective paint on the plate, protecting the metal from corrosive processes, can burst into flames.
And finally, the ignition of the brake pads can lead to trivial negligence of the driver. For example, if the return mechanism of a parking brake gets acidified, its pad stops moving back, and it will start jamming. Without fixing the problem in time, the stress will begin to build up, which will cause a fire.
What are the natural causes for brake pads to catch fire?
Natural aging of the pads
The pads are a consumable item that must be replaced in a timely manner. In disc systems, they are designed for 30-40 thousand kilometers of mileage, after which they are dismantled in order to install a new set.
This is due to the specific structure of the part. The pad refers to a metal plate with an abrasive lining, where the latter gradually wears out in interaction with the cast iron disc and becomes dusty.
It can also deteriorate against the background of overheating or peeling from the base. Among the pronounced signs of wear are a decrease in fluid volume, or a creaking or grinding noise when dropping speed.
Wear on drums and discs
Like pads, these parts belong to the group of consumables, although they function 2-3 times longer. Thus, a quality mechanism can survive 2 sets of pads, after which it will also be replaced with a new one. The allowable wear is noted in the documentation and cannot be exceeded. Among the obvious manifestations of drum wear, a runny color or strong vibration in the steering wheel when pressing on the pedal is mentioned.
Among the critical breakdowns of the system, leakage in the brake line should be singled out. This is accompanied by the fact that when you squeeze the pedal, the latter goes almost to the floor without significant resistance, but the car practically does not slow down.
If you find such a problem, immediately stop driving, using the engine brake, or the handbrake, not forgetting about the rules of safety. Next, find the leak, repair it by replacing the tube or hose and re-pump the system. It is strictly forbidden to operate the machine with a faulty hydraulic line.
Worn and wedged caliper guides
The brake cylinder pistons will become oxidised and may begin to seize. As a result, the effectiveness of the braking system decreases rapidly and also becomes uneven. Over time, you may find that when you depress the brake pedal, the car will begin to veer sideways.
At times, the jamming causes the discs to overheat and burn, as well as the pads to wear rapidly. If the problem is not corrected as soon as possible, the safety of riding the car will be endangered.
In most cases, cast iron is used to make discs. And this material is vulnerable to sharp temperature jumps. Therefore, try to avoid overheating of disks, especially when driving on mountain serpentines or towing a heavy trailer.
If a breakdown indication with a brake icon appears on the dashboard, it is most likely due to a decrease in the fluid level in the expansion tank. Never ignore these symptoms and begin troubleshooting to avoid more dire consequences in the future.