Hi all, We are prepping a trailer for sale and rebuilding absolutely everything...so my awesome guy just rebuilt the original Dyna-Trail furnace and I am sharing the resources we used. We (mostly he) took it completely apart, blew it all out and removed all the old (likely) asbestos gaskets, sanded and repainted it completely.
The brushes in the motor still had a tiny bit of life in them but as we had it this far apart we sent the motor in for a rebuild/ brush replacement. After the rebuild and re-assembly it did not light...At this point in our brilliance we figured gee we probably should have tested to see if it even worked before we took it apart,..doh... well after some online searching we had two possible options on why she wasn't lighting up. As we only had one newly filled tank hooked up it was either air in the line/not enough pressure or a dirty or broken thermo couple. So we watched the video below and cleaned the thermocouple on our shirt sleeve as the poster did in the video (never ever, sand it just wipe it clean), then we did the thermo couple test as shown, and as well we put a second tank on front and turned both tanks on and left it for an hour to pressurize the system. It works now.. Not sure if it was the dusting off of the thermo couple or the added pressure but she a happy quiet rebuilt furnace now.
Here is a video of how to test a thermocouple