Portable non-electric Steam Cleaner

You can buy one, no need to build it. Landa makes them and so do a few other manufacturers.
i

You need power to run the pump. Fact of life
Gunner
The methodology of the left has always been:
1. Lie 2. Repeat the lie as many times as possible 3. Have as many people repeat the lie as often as possible 4. Eventually, the uninformed believe the lie 5. The lie will then be made into some form oflaw 6. Then everyone must conform to the lie

The pump can run on an ifernal combustion engine - diesel, gasoline or propane. Can also be run off compressed air if the truck engine runs. Nothing stopping a 12 volt pump motor from being used either. Not real practical - but definitely possible.
The original Steam Jenny makes a gasoline powered one.

You are absolutely correct indeed. Ive only seen them that had a electric motor to run the ignitor and blower
Gunner
The methodology of the left has always been:
1. Lie 2. Repeat the lie as many times as possible 3. Have as many people repeat the lie as often as possible 4. Eventually, the uninformed believe the lie 5. The lie will then be made into some form oflaw 6. Then everyone must conform to the lie

The gasoline powered ones are almost the ONLY way to clean up equipment for field repair. The only option is a generator set to run the electric one.

How about a gasoline powered hot water pressure cleaner?

Only $6,400!

See? If you had described -all- your requirements in the -first- post, responses would have been better keyed to your needs. That'll teach ya. The fix is to tell your mechanic to PW the engine and chassis after every oil change. That's better than being stopped by the inspectors at a weigh station and being arrested by the DHS for carrying explosive devices across state lines, which your specified device would cause, eh?
Oh, hell. Just buy some waterproof overalls, duuude.

Or cans of engine cleaner. Clean the damn thing once ina while. Live steam is dangerous, and 'superheated' requires high pressure when can rupture the boiler. You can't use a "water heater" to produce steam. It has to boil. Also, steam damages the wiring and plastics used on most vehicles.

It sounds like you are describing a propane-powered steam generator used for taking wallpaper off of walls. I suspect it would take a fairly large unit to generate sufficient steam for cleaning the underside of a truck. But these steam generators can be rented for a tryout.
Joe Gwinn

You need two. You can make a small pressure washer that'll fit in a Possum Box on the truck, maybe an 18" cube, but it isn't going to be heated - just a little 4-HP gasoline engine and a pressure pump. You can hit the area in question with some Gunk Engine Brite from an aerosol can to soften up the crap before you blast it off with cold high-pressure water.
Or a thought... If there's space, you can hang the pressure washer pump off an APU for your sleeper heat and lights, or on the PTO from the main truck engine. The hard part would be clutching it in and out. And it is possible to use stack heat from the engine to preheat the water - 140F in is almost as good as 200F for the real steam ones. But you start hanging odd bits off the engine and APU to 'build it in', and you're going to get a lot of raised eyebrows at the Safety Inspections - Plan on explaining the whole thing to every inspector that wants to ticket you for something illegal in their state...
Steam pressure washers are generally a whole lot larger because of the boiler section - and you'd have to dismount it and move it into the open, or deal with an exhaust stack from the boiler if permanently mounted - Possible, but not easy. You probably could make brackets and mount one on the frame just ahead of the rear axle, or on a cargo pallet between the Cab and Fifth Wheel - IF you don't have an Interstate Sleeper. And you'll have to drop the trailer to get the stack clear.
But you can probably come up with a LOT better use of the cargo weight and space on the frame rails - like another tank and 150 gallons of fuel to get across a high-tax state without contributing to the delinquency of a government.
I would keep the Steam Jenny at home base and clean the chassis about once a month or when you see it starting to get bad - if you do get a breakdown on the road the layers of crap won't be all that thick.
WD-40 (it's all solvents...) and a roll or two of sacrificial Scott Blue Shop paper towels can get that little bit of gunk off, and a whole lot easier to carry. Carry it in a 5-Gallon plastic bucket with lid that can be used to cart away the trash.
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