[joeydurango]

That's all good to know, thanks!

We've been filling up at 1/4 (1/8 in extreme cases), even though I know in our tank there are several gallons sloshing around even when the gauge reads completely empty. I figure the pump shouldn't have to "pull" from the tank, I just want gravity to do its job feeding the pump. It does seem a little louder when the tank is less full.

The pump is mounted on the inside of the frame rail as close as possible to the tank. Plenty of airflow, and it does appear to be loudest when going slow, in traffic, when it's hot. Going through Moab yesterday it must have been 100*, and waiting in a turn lane it was sure making some noise.

As long as this is normal I won't worry about it. Just didn't know what to expect...