The fact that you even know what a decelerator pump diaphragm is, or what it does, means that you've come to the right place. AutoAnything will never overcharge you for a part because it's obscure or hard to pronounce. In fact, unlike the shady dealer, we guarantee the lowest price possible on factory-equivalent and factory-replacement decelerator pump diaphragms. And, we won't charge you a dime—or even a penny—for shipping.