Renault Logan II Brake Pedal Pulsation: Warped Discs or Something Else?

Why the pedal pulses

On a Renault Logan II, a pulsating pedal under braking is most often caused by uneven brake disc surfaces — commonly called warped discs. In reality, it is often pad material transfer or corrosion creating high spots, not a bent disc. Less common causes include a sticking caliper, worn slide pins, hub runout, a failing wheel bearing, or an ABS wheel speed sensor triggering when it shouldn't.

What to check first

• Front brake discs and pads: measure disc thickness and runout with a dial gauge; look for scoring, blue spots, or uneven pad deposits.
• Caliper and slide pins: check for seizure, uneven pad wear, and free movement.
• Wheel bearings and hubs: excessive play or hub runout can mimic warped discs.
• ABS wheel speed sensors: scan for fault codes and check live data if the pedal pulses at low speed without heavy braking.

Is it safe to keep driving?

Mild pulsation is usually not an immediate emergency, but it will worsen and can lengthen stopping distances. If the pedal pulses strongly, the car shakes, pulls to one side, makes grinding noises, or the pedal feels soft or sinks, stop driving and get it inspected. Otherwise, drive gently to a workshop soon and avoid high-speed or heavy braking until it is fixed.

This material is AI-generated and for informational purposes only — it does not replace an in-person diagnosis by a qualified mechanic.