what would cause the brake pad to not go down after backing on 2006 Chrysler PT Cruiser

brake went down when starting car, has occurred three or 4 times when backing up

Asked by for the 2006 Chrysler PT Cruiser
1 answer 4 comments
Are you talking about the brake pedal? You asked about it not going down, then say it goes down?
yes I am talking about the brake pedal, the one near the gas pedal. It goes down when I first start the car and shift into reverse, the I take my foot off the pedal to back up it is when I step on the brake pedal agin to stop car from backing up that it will not go down. Seems after a few seconds if I try it again it will go down. Today I did not let car warm up much and it did it for the first time going forward
possibly vacuum to the brake booster issue; Have vacuum supply, check valve tested. Would seem the vacuum is not recovering quickly enough.
ok thanks for your help