Why do my BMW X5 45e brakes look rusty and clunk at slow stops?

Short answer: On the X5 45e, regenerative braking does most of the slowing, so the normal brakes sit idle and the rotors can look rusty and grooved. The grab or clunk at the end of slow stops is usually the hand-off between regen and the normal brakes. Owners clean the rotors with a few firm stops in a safe place. Have the brakes measured if the grooves are deep or the pedal feels different, and check recall 21V062000.

Symptom: The rotors look rusty or have grooves, or there's a grab, jerk or clunk right before the car stops at low speed.

What to check first

1. Run your VIN at nhtsa.gov/recalls for 21V062000 (integrated brake system).
2. In a safe empty area, make a few firm stops to clean the rotors.
3. Notice whether the clunk changes in Sport or Eco Pro mode.
4. Have a shop measure rotor thickness and pad life.
5. Report any longer stopping distance or soft pedal right away.

Likely causes

1. Friction brakes barely used because of regen. Regenerative braking (regen) means the electric motor slows the car and recharges the battery, so the normal brake pads and rotors do less work. Owners said that lets surface rust and grooves build up on the rotors.
2. Hand-off between regen and friction brakes at low speed. Near a full stop, the car switches from motor braking to the normal brakes. Owners felt a grab or clunk at that moment, and one found it went away in Sport mode, which changes regen.
3. Cold or rusty performance brakes. Owners with M Sport brakes said they can grab when cold or after sitting in damp weather.
4. Brake system fault (recall or hardware). Recall 21V062000 covers some 2021 X5 xDrive45e cars whose integrated brake unit may not have been welded properly. Have any real change in pedal feel checked.

What it usually costs

Owners didn't post repair prices. The dealer found nothing on one car, and another's said the rotor wear was cosmetic. Recall work is free.

Is it safe to keep driving?

Usually yes if the brakes stop the car normally. If the pedal feels soft, the car takes longer to stop, or a brake warning appears, stop driving and get it checked.

DIY or shop?

Cleaning the rotors with firm stops is DIY. Replacing pads and rotors is a moderate DIY job. Anything with the integrated brake unit is dealer work.

Recalls, bulletins and complaints in plain words

• Related recalls: NHTSA lists 21V062000 (includes 2021 X5 xDrive45e: the rotor and shaft inside the integrated brake system may not be welded properly and could separate during hard braking) and 21V089000 (2021 X5 40i: right front brake disc fasteners). If your car is part of a recall, the dealer fixes it for free.
• Plain words: The complaint count below shows how often owners reported problems that mention these words to NHTSA. A count is not proof of a defect. NHTSA files the 45e under the X5, so this count covers the whole X5 line.
• NHTSA complaints: 42 keyword-matched complaints for BMW X5 (all, including xDrive45e) 2021–2023 (of 217 unique complaints queried, NHTSA complaints API by model year, queried 2026-11-03; keywords: brake, grind, clunk, noise, rotor, squeal). This counts complaints that mention these words. It is not a defect finding.

What owners report

• In BMW X5 45e – brake discs showing abnormal wear? on Reddit r/BMWX5, a 2022 X5 45e owner at about 56,000 km found deep grooves and rusty-looking rotors. Replies said regen means the friction brakes are barely used, a 40i owner's dealer called similar wear cosmetic, and owners said a few hard stops or Sport mode use helps clean the rotors.
• In 45e - Brake noise when stopping at slow speeds on Reddit r/BMWX5, a 2023 X5 45e owner at about 35,000 miles felt a grab or clunk at the very end of slow stops. The dealer found nothing, and an iX loaner felt similar. Replies said M Sport brakes do it when cold, one owner found it didn't happen in Sport mode, and another mentioned Eco Pro changes how the car coasts and regens.

Quick tip

Rusty, grooved rotors are common on plug-ins. Use the brakes firmly now and then, and have them measured at service.

Vehicle focus: BMW X5 xDrive45e plug-in hybrid (G05), 2021-2023.

Safety / mechanic note

Brakes are a safety system. If anything feels wrong, have them inspected. Verify with a mechanic.