why is my top hose at the radiater swelling up? on 1996 Acura TL

i just got a new radiater, thermosat, sensor and fan motor. if the top hose is swelling up is that because it has air or what else could it be?

Asked by for the 1996 Acura TL
could be just a weak hose or headgasket issues.have you overheated car badly?
2 more answers
Agree with above. Hose has weakened and can't support the radiator pressure anymore. Replace hose and that should resolve problem. Hopefully, this is all it takes unless you are getting too hot. Then you could have another issue.
Weak hose?...replace it first and see if new that fixes your problem. Could be more serious problem like Greg says.