Rambo,
Judson has made lots of proto-type truckmounts throughout the years.
The very first production truck mount that we made, was not the TNT, it was called the Pro.
This unit relied on a automatic pump-out full time. The recovery tank was only 25 gallons. The problem with this, is that you are totally relying on the pump-out to work. So to elimiatate this dependency, we designed the TNT, with 125 gallon recovery tank.
One interesting proto-type unit that is still running today, that was designed in 1985. This unit had a belt driven hypro pedistal pump.
But the odd part of the design was the recovery tank was a 4 foot long by 6 inches pvc pipe.
This unit is still running today. It's cleaning hotel rooms at Myrtle Beach, all day long. If you would like to talk to the owner of the unit, I can give you his phone number.
Through the years we have tried every type of pump that you can imagine, and what we offer today on our existing truck mounts, is the Hypro diaphram pump that everyone's using. It has it's own 12 volt motor and a float switch in the recovery tank. With the switch, it only runs a short period of time between cycles. This extends the life of the pump and minimizes total amp. draw. With and external pump, easy to access. Servicing the pump is and easy thing to do.
Thanks,
Les