When set to Auto mode my Air Compressor 15020C will not shut off. I replaced the Check Valve and now it just runs and never reaches the max pressure and shuts off. I just have to turn it off manually. See photo. Used to go to red line and stop.

An air compressor problem could stem from one of many issues, such as an air leak guide
Here , an oil leak or a broken part. In some cases, you might have insufficient pressurization or air flow. In other cases, the compressor might fail to start up or stop running as prompted.