I have a 2016 JCB skid steer that is over heating periodically. When I first got it I was told when it was serviced they overfilled with coolant , hence the overflow bottle was full and overflowing. When cold I emptied the bottle, to the cold mark and put it back into the radiator, as it was low. It worked all day without a problem except the overflow bottle was overflowing. I checked it again this morning and the bottle is full and the radiator is low. Could this be as simple as a thermostat sticking?
More of a radiator cap problem I would think.
Could be a cracked seal on the cap, could be the wrong cap, could be a damaged seat on the radiator, could be a loose hose to the overflow bottle, could even be a crack in the hose to the overflow bottle or anywhere else in the cooling system.