Is it necessary to replace brake pads when changing brake discs?

[VivienneDella]

Replacing brake discs does not necessarily require replacing brake pads. If the brake pads still have sufficient thickness, they can be retained. The function of brakes is to reduce speed or bring the vehicle to a stop. Their working principle involves converting the kinetic energy of the moving vehicle into thermal energy through friction between the brake pads and brake drums, as well as between the tires and the road surface, thereby slowing down or stopping the car. Causes of brake failure include: 1. Impurities or poor sealing in the brake master cylinder; 2. Failure of the vacuum booster pump; 3. Contaminated brake fluid; 4. Oil leakage from the brake master cylinder or wheel cylinder; 5. Air leakage from the air reservoir or pipeline connections; 6. Severe overloading; 7. Carbonization of the brake drum; 8. Insufficient brake fluid in the brake master cylinder; 9. Wear of the brake master cylinder piston.

[DiValentina]

I drove trucks for over a decade and often repaired them myself. When replacing brake rotors, you don't necessarily have to change the brake pads—it depends on the situation. If the pads still have sufficient thickness, show no uneven wear patterns, or make no noise, you can definitely save money by replacing just the rotors. However, most of the time, I recommend changing both for added safety since rotors and pads work as a matched pair. Old pads might be rough and accelerate wear on new rotors, leading to reduced braking performance or even road hazards. From experience, I've learned that safety comes first—inspect your brake system at least every six months. Use a coin or caliper to measure pad thickness; if it's below 3mm, it's time for a replacement. Ignoring this could turn minor issues into major problems.

[SanFelicity]

I drive a small car to and from work, always keeping an eye on my budget. You don't necessarily have to replace the brake pads when changing the brake rotors, as long as the pads still have sufficient thickness. I measure it myself using a ruler or a coin to check the gap—if there's more than 4mm of pad material left, they're still good to use. However, if the rotors are worn out and the pads are nearly gone, don't delay. Mismatched components can lead to poor braking performance, and you might end up making extra trips to the repair shop, spending more money. During regular car washes, take a quick glance at the wheels to check for brake dust buildup or signs of uneven wear. Saving money is good, but safety comes first.

[DeManuel]

This is a common issue during car repairs. Replacing brake discs doesn't mandate changing brake pads, but it's usually recommended to replace them together. If the discs are worn thin or have scratches requiring replacement, the pads have likely worn out too. Our inspection standard for pad thickness is replacement recommendation when below 3mm. Keeping old pads may cause accelerated wear or noise from new discs. Don't underestimate compatibility - it affects overall braking efficiency. Regular maintenance is key for prevention.