Home › Forums › Stay Dirty Lounge › Service and Repair Questions Answered Here › 04 Chevy Classic vacuum leak? › Reply To: 04 Chevy Classic vacuum leak? September 8, 2020 at 3:29 pm #963576 Richard KirshyParticipant If you suspect a vacuum leak there are several test methods that can be done if you search youtube you should have no trouble finding them. Also a check test of your fuel trims can also be a good indicator again a youtube search will be helpful.