Hey guys, workin on my buddy's '99 A4.

Bolted to the back of the motor there's a plastic piece called the coolant outlet or somethin like that, anyway it was leaking so we got a new one at Napa.

The hose that goes to the heater core off that piece has a little snap-in connector on the end as I'm sure you are aware.
When I push it in place I hear a satisfying "snap", but when I pull on it with medium effort it just comes off.

Not sure if this is a normal thing or if I got a faulty coolant outlet as I'm not sure how it behaved before it was replaced (I didn't do the replacement). I'm just scared with enough pressure it'll pop off. Any advice?