My foretravel is fine but our friends have a 04 Tiffin Allegro Bus and traveling it's getting hot (220 buzzer going off). He never had problems till last year. He just put a new hydraulic pump on and didn't help. He has Cummings 350 HP , My Cummings is the M11 425 HP and not an issue . Any suggestions? Thanks Art
Art,
It sounds like a radiator issue; does the temp go down when he slows down to 55-60 mph? If so, it could be plugged core or loose fins, though fins usually go in older (10-15 yrs) coaches. If temp stays high at slower speeds, may be thermostat.
Assuming side radiator:
Clean outside of radiator (actually CAC)
Change thermostat-- inexpensive and a possible cause.
Verify operation of the side radiator fan(s). Some have two speed fans and need to verify it kicks to high when temperature rises.
Brett