The new trailer we had had a brass fitting above the tires fracture and leak out two full bottles as we drove from Flagstaff to Needles.
Our current trailer this last month had a propane smell inside as we were prepping it for a desert trip. I sprayed all the fittings underneath remembering our last problem but found nothing. Letting it air out and then immediately returning inside with my sniffer I located a strong smell at the heater underneath the stove. Pulling the grate off and spraying the exposed fitting created bubbles, lots of them. I got some wrenches and loosend the fitting then snugged it back down. No more leak and the big propane bottles up front remained full after 5 days in the dunes using the heater every night.