Brake system lock-up. What are the steps to address a seized brake system?
Experiencing seized brakes is a significant concern as it can greatly impact the performance and safety of a vehicle. Fortunately, addressing this issue can be done easily without the need for professional mechanic assistance. Discover the necessary steps to take when your car’s brakes show signs of seizing.
Brakes that are seized often occur due to the presence of carbon deposits in the braking system, resulting from the buildup of residual brake fluid and other substances during routine use. The main contributors to a locked system are the brake pistons. When these pistons become seized, the brake shoes gradually impede the movement of the wheels, and the brake fluid, overheated, reduces its responsiveness when the brake pedal is pressed.
Seized brakes — symptoms
The most common symptom of seized brakes is primarily reduced braking effectiveness. Malfunctioning jaws can also be easily recognized by excessively hot rims and the smell of metal or burning that comes from around the wheels. Black coating may also appear on the wheels—this is dust from excessively worn brake pads. Decreased performance and increased fuel consumption may also be related to seized brakes.
If you suspect that something is wrong with the braking system, it is worth removing the wheel and checking the brake discs . If we notice rust or tarnishing on them, it may mean that the pads do not have direct contact with the disc, which is another symptom of a seized system. Let’s also look at the pistons to check their tightness—blocked brake pistons can be recognized by spot fluid leaks. The last symptom of the problem will be the squeaking of the brake pads , which rub against the disc without returning to their original position. You can hear them, especially when they start slowly.
Seized brakes after parking
The sources of brake problems can be traced to everyday operational negligence. If we use our car rarely or only drive short distances, the braking system is subjected to greater loads. It is therefore worth “starting up” seized brakes after stopping by braking sharply several times while driving on an empty stretch of road—this way we will remove some of the deposits present in the system.
Sticky handbrake
The handbrake system is another place that can generate problems with the entire system. A stuck handbrake can be recognized by the fact that when the lever is released, the brake does not release, generating additional friction while driving, which consequently causes overheating of the braking system.
As before, here too, the presence of corrosion has the greatest impact on proper functioning—this time we will look for it on the emergency brake cable. In winter, it happens that the cable freezes, which also causes blocking of the system. Let’s also check the return springs, which wear out over time, crack, and lose elasticity, as a result of which the “manual” is not fully released.
Locking brakes — the most common causes
Seized brake piston
The brake pistons mentioned at the beginning are the place where we will first look for the causes of locking brakes. Their sockets should be checked for tightness, corrosion, and proper functioning. A dirty or rust-covered piston will have difficulty returning to its initial position when the brake pedal is pressed, causing a weakened response on the brake shoes . We can then try to regenerate the piston ourselves by cleaning it from deposits and oiling it with a grease resistant to high temperatures. However, an excessively corroded piston should be replaced.
Seized caliper guides
Locking brakes may also be the result of seized brake caliper guides. In this situation, the clamps do not maintain their position and move along the yoke axis. The result is damage to the cover seal. A simple remedy is to inject a bit of grease into the inside of the guides. However, if this does not work, it will be necessary to replace the seals with new ones.
Worn brake pads
Seized brakes may also be the result of excessively worn brake pads . In this case, you need to remove the wheel and look carefully at the pads. If they are suitable for replacement, it is not worth postponing this operation. It will also be a good idea to check the braking power on a dynamometer at a diagnostic station.
Sludge in the brake fluid
The cause of seized brakes may also be sludge and other dirt present in the brake fluid , e.g., resulting from long periods of parking or detached pieces of rubber from stiffened cables. In this case, the master cylinder piston is unable to move fully, reducing fluid pressure in the entire system. This affects the operation of the brakes, ultimately reducing the braking force. Replacing the fluid and regenerating the pump by a specialist is the most common solution in such a situation. In extreme cases, you may have to purchase a new part.
Seized brakes. What should I do if a fault occurs?
Seized brakes, although they most often do not immobilize the car, can be a big problem—they reduce both performance and safety, especially at high speeds. The methods described here are the basic remedies that you can use to deal with seized brakes yourself.
