Sir, With me you will never have that kinfd of issue, If a part is defective and not working i will replace it without asking a single question. If i have a replacement in stock it will be shipped same day and in certain cases I will pay you shipping to ship it back to me it all depends how long it has been since you bought it.Typically within 2-3 weeks I will pay shipping and more then that a customer would but there are always some exception to it.Customer service is what I like. I'd pay a little extra knowing if I have any problems there would be awesome customer service to back it up. Too many stories of ppl having to pay to ship back a defective part. And something as simple as a valve don't leave us without wheels for a week to save a few bucks. Eat that little bit and you will grow a good customer base.