Whether holding your GPS in place on your windshield or securing your child's artwork to a window, suction cups come in handy and are surprisingly expensive to fix. Luckily, repairing a suction cup yourself is an easy task that can be accomplished in less than an hour.
Purchase a car dent remover suction cup or other industrial quality suction cup.
Cut away the built in rubber handle with a razor blade. You should only have the cup left when you are finished. Be careful not to puncture the cup.
Take off any residue left by the rubber handle with your razor.
Place the suction cup's back against the plastic frame of the old suction cup; note where the new suction cup would connect to the old frame's adhesive plate. Draw a line around the perimeter of that connection with a permanent marker.
Cut around the line drawn by the marker with scissors. The line delineates the ideal circumference of the suction cup. Cut away all excess circumferences.
Use rubber-to-rubber glue to adhere the new suction cup to the old frame. Let dry for 24 hours before use.