I was just riding my RV hauler around to get things movin. Do this about once a week. This time coolant is bubbling out of the radiator cap. My question, has my cap stopped working, thermostat, or something else? I’m not a novice, but know these beasts are lil different. I’ve done many hot rods and conversions. Last one was a 4BT in a 1982 Jeep Scrambler, 5spd manual, Dana 44 n 60. Thanks in advance.