you have to put a "light" down inside the horn and find the leaks first. i does help to make sure the cups are level or flat before you put them in. also to heat them, the pads that is with an pad iron prior to the first press of the pad. when you find the leaks just heat the pad and pull with a pin on the side with the leak or sometimes just gently bend or twist the cup. there are places on the internet teaching you this stuff.