I often find the metal inserts slide out of those long plastic pipes.  Need to slide the inserts back in and put a screw in the side to stop it to happen again.  Choose a screw with a head that is not very high, so you can slide the hose over it.  And don't put it too far off the end, so the hose would still reach over it.  Obviously, you would have to put the clamp behind the screw.

By now most of the ends have been broken off totally and traveled into the hose, or are cracked wide and about to be falling off.  Once those ends are off, the insert can slide out with the hot coolant lubricating.  And when they fully out, the clamp will loose holding strength and the hose can slide off, making you loosing all the coolant and overheating in half minute.  

So, it is time for all of you to get them done.  And don't just inspect and leave it if it's not broken.  Drill a small hole on the side and put a screw in and slide the hose over it, then put the clamp behind the srew.  Done.  We have enough other troublesome items to worry about.  Don't need this to give a surprise if we can help it.  

Zoltan