There are 1 owner-reported fuel system complaints for the 2021 Ram ProMasterin NHTSA's database. These are unverified consumer reports and may not reflect confirmed defects.
This vehicle is a new Thor motorcoach model 18m with onboard propane system. Within the first 2 weeks of ownership i turned on the propane and immediately a rubber propane hose burst at a bend and started leaking propane. I was able to shut off the supply at the tank and get it in for repair where they replaced the hose. On December 3rd we drove the van 9 hours to Disney and parked for check in. upon return from check in I smelled propane and heard hissing under the van again. The fire department was called to the scene and they found the main fitting on the inlet of the tank leaking. It bled about 3/8 of the propane before they secured it enough that I was able to get it home. I took it to the dealer again for repair yesterday and they made a repair. I left the dealer with 1/4 tank of propane. This morning there was a very strong smell of propane again and my tank is empty. I have notified them again and am waiting....... I am unaware of where it is leaking from now, but I have lost all faith in the safety of this propane system and thor motorcoach quality control.
Complaints are unverified consumer reports submitted to NHTSA. A high complaint count may reflect vehicle popularity, not defect severity. Data sourced from NHTSA public records.
Data synced from NHTSA on Apr 26, 2026