Make sure that you get a pump that is cast. Stay away from the Aluminium stuff. Also, you may want to shine a light into the tank to make sure that there is no rust. you will need to make sure you have a safety valve to keep the compressed air from coming back to the pump from the tank to the pump. This will cause the pump to lock up. If you need more help, just let me know, I sell and service compressors as part of my company.