Taylormade fenders are great and long lasting. Taylormade also offers a very fair warranty program. In the past, I was able to exchange a leaking fender with a new one, on the spot with no receipt, at West Marine. Other brands, maybe not so great.
Recently, we moved the boat to a side tie slip and I noticed a fender loosing air thru the valve. With the corona virus lockdown, I started poking around the internet and found several videos on changing football valves. I never knew how easy it was to replace these valves.
The replacement valves are available on Ebay or Amazon (a dozen replacement valves for less than $10). Easy enough to throw a few in the spares box on the boat.
Hopefully this will help someone save a bumper.