The reference to a "Jake Brake" is right on the money. On my 2002 3575RL, the pump is under the 'fridge and there isn't a very good access hole to it. I can't believe that something that retails for almost $50K will make that kind of noise....
You better believe that quieting this beast down is rather high on my list of Things-To-Do. I'm saving this thread!
Eric