Crash, sorry to hear about your problem. I would offer to help, but I only have a 250 and no 5th wheel or goose neck setup. If worse comes to worse, try calling a towing company like Randy's (Road One. ) They have wreckers that range in size from F350's/Ram 3500's to HUGE flatbeds for moving large earth movers to wreckers to tow fully loaded over the road trucks. Their # is 596-6067, thier address is 5608 E Pike's Peak (access from Platte or Airport, but not Powers. I deal with them frequently at work and they are very good people, and very professional. (note: Colo Spgs. Police Dept. uses them a lot).
When you find out what the problem was, let us know. And just curious: what place in Denver was your pump rebuilt? Well, good luck.