Whenever the car engine isn’t warm and I slam on the brakes, they barely respond. I have replaced the master cylinder, abs hydraulic module, brake booster, calipers, pads, and rotors, and it still has about 20% normal braking power when the engine is cold. Just got it back from the dealership again. Dealer said no vacuum leak found, no leaks found, abs module checks out fine, and said the check valve passed diagnostics. The problem remains. This has been ongoing for several years now. May have contributed to an accident in 2023. Not sure as my wife was driving. When the engine is warm, the brakes work perfectly.