vaseline doesn't sound like a good idea, since it would mix in with the coolant.
here's my trick, yeah, i know it's simple.
put water on the inside of the hose (mostly just to remove the powder residue that seems to be on Honda OEM hoses), and then push the hose on as far as you can. then take if off, and put water on the inside again. after trying the first time, the hose streches a little, so it goes on easier the second time. This has works for me on the two radiators I've replaced in my Hondas.
here's my trick, yeah, i know it's simple.
put water on the inside of the hose (mostly just to remove the powder residue that seems to be on Honda OEM hoses), and then push the hose on as far as you can. then take if off, and put water on the inside again. after trying the first time, the hose streches a little, so it goes on easier the second time. This has works for me on the two radiators I've replaced in my Hondas.