Water getting into fuel tanks

[Wbburns]

Hope someone can shed some light on my problem. I recently bought a ‘04 cv713 dump truck that had been sitting for a while. Had to put a transmission in it and finally got it on the road. The first day, lost air and had to replace air compressor. Shortly after installing air compressor (15 min), letting the truck idle, it began miss8ng terribly and blowing blue smoke. Changed fuel filters (don’t know when they were changed last, so I knew it would only help) and found lots of water. Drained all the fuel in both tanks and refilled. Next day STILL had water in fuel and fuel tanks. Drained off water again (10 gallons of fuel before it drained clean). Restarted and ran for a day. End of day, started missing again. Parked, let rest and drained another 10 gal of fuel/water. It must be getting in from somewhere. Any ideas where? 

[joes mack]

do you have to add antifreeze to the truck. and or do you haul in wet areas or go through truck wash.

[Wbburns]

I’ve added both antifreeze and water (lost about 4-5 gal when disconnecting lines to install air compressor pump). Don’t haul in wet areas or truck wash. Water isn’t getting in through the top of the tank for sure. 

[Mackpro]

The fuel return line above the air compressor swapped with the coolant line to the air compressor? I have seen it happen 

[Brian L Blaylock]

Does your truck have fuel heaters in the fuel tanks if so you could be getting coolant from one of them if it is cracked