Why does fuel consumption increase after replacing brake pads?
3 Answers
Brake caliper not retracting, apply some grease on the caliper pins. Maintenance: Brake pads need to be replaced every 3 to 6 kilometers. In a vehicle's braking system, brake pads are the most critical component, as the effectiveness of braking entirely depends on them. Brake pads are generally composed of friction material, steel backing plate, and adhesive heat insulation layer. The steel plate should also be regularly coated to prevent rust. When the brake pad indicator light comes on, it indicates that the brake pads need replacement. If this occurs, they should be replaced promptly. Brake pads also need replacement if their thickness is less than 0.5cm. Braking working principle: It primarily relies on friction. The vehicle uses the friction between the brake pads and brake discs against the ground to effectively provide sufficient stability and controllability in the braking system, thereby ensuring the driver's safety.
Just helped my dad troubleshoot a similar issue a couple of days ago. Found that new brake pads need a break-in period when paired with old rotors - the friction surfaces don't mate perfectly during the first few hundred kilometers, actually creating more braking resistance than normal. No surprise fuel consumption spikes. If abnormal fuel consumption persists beyond 300-400km, beware - it's likely caused by sticking caliper pistons or seized guide pins. I've personally seen apprentices forget to lubricate guide pins, leaving pads dragging against rotors until wheels became burning hot to touch. By the way, overheated hubs often emit burnt smells - get it checked immediately as this can drink 2L extra fuel per 100km. Manual transmission owners: test your neutral coasting distance. Significantly reduced roll means your brakes are dragging.
Last time, my neighbor Lao Zhang's Magotan had the same issue. After changing the brake pads, it consumed an extra 1.5 liters per 100 kilometers. I asked him to feel the wheel hub temperature, and the left front wheel was scorching hot. Back at the repair shop, they found the piston was rusted and stuck. The technician used professional tools to rotate and press it back into place. Nowadays, many models with electronic parking brakes require special reset tools. Ordinary small shops might damage them by forcing it. Remember not to rush testing the brake performance right after changing the pads. For the first 300 kilometers, apply the brakes gently to allow the friction material to fully seat, and the fuel consumption will naturally decrease. If the issue persists after a week, it's likely due to grooves on the brake discs causing poor contact, requiring both the discs and pads to be reworked.
