Truck Bed Wash Out and Drainage holes

I was going to pressure wash the inside my truck bed, dust was getting into from our back roads, seem like bottom of endgate seal is come off and might be letting dust in.  I was going fix it but my question here is, that was wondering if there is drainage holes in the bottom of truck bed, incase you get water in it. And was wondering if it does, if that's another dust source area.

There are 5 drains in the bed of your truck. They have rubber flaps over them which SHOULD prevent most dust from coming in but nothing is air tight on your truck..

There is a drain at the front of the bed under the trim, and two on each side of the bed. If you have a stick or leaf or something stuck in your drain it can allow the dust in. Also wouldn't suggest using a high pressure washer directly on the flaps as they could tear. Easy enough to clear by hand.

I would not pressure wash it a garden hose will do it.

The bed is not sealed and yes dusk and dirt will come through the drain holes.

Just take the mat out and hose it down here is a link that may interest you.

http://www.chevyavalanchefanclub.com/cafcna/index.php/topic,150120.0.html

Thanks, good advice