We purchased a used 2024 Chevy Colorado WT with a little over 4,500 miles on April 9th. A couple of days later before starting the vehicle the brake pedal would sink all the way down to the floor. This happened twice. So I made a service appointment with the Chevy dealer on April 14th. I told the service advisor that the brake pedal sank to the floor twice before starting the vehicle. He said they would take a look at it. When I went to pick up my vehicle the next day, the service advisor said the technician could not duplicate the problem. That same day, the brake pedal sank to the floor before starting the vehicle. So I made another service appointment the following week on April 23rd. I have videos to prove that the brake pedal would sink all the way to the floor before starting the vehicle. The service advisor told me that that technician duplicated the problem and they will order parts for it. The vehicle has been at the dealer since then.The service brake issue is a safety hazard that needs to be addressed.