The reason may be not only malfunctions of the brake system.
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There are other nodes that give a feeling of uneven, ragged deceleration, says Alexei Revin, an expert at Za Rulem.
1. Gear box
On a car with an automatic transmission, do not touch the brake pedal: if there are jerks when coasting, the problem is in the automatic transmission. The reason may be insufficient or excessive liquid level in the machine. Defects can be hidden in the valve body, torque converter or in the control electronics.
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On the mechanics, twitching when braking the car can be triggered by unstable engine operation. Or is it a faulty throttle position sensor.
2. Brake discs and/or drums
Jerks during braking can appear immediately after replacing the discs / drums – and then it’s either a poor-quality spare part or an incorrect installation.
3. Defective or worn brake pads
These pads have a non-constant coefficient of friction. As a result, the friction lining either works normally, or it burns or melts – and then the coefficient of friction drops. The alternation of such processes leads to jerks.
4. Wheel bearing play
If there is a large gap in the bearing on which the wheel rotates, then the brake disc (drum) will hang unpredictably relative to the brake shoes. Riding with a loose bearing is very dangerous.
5. Wedging of the brake mechanism
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Jerks during braking can also be provoked by a drum brake mechanism. The culprits may be a wedged brake cylinder and an unadjusted handbrake drive.
The car slows down with jerks – this is always the result of malfunctions of systems that affect safety. Read more about other malfunctions in our material.
Photo: screenshot from the movie “No brakes”
