I always keep a spare, brand new hose reel (with hose on) in the van.
That way if any problems arise with the reel I'm using, I just switch to it straight away with no loss of working time.
If the problem is a connector, I'll replace it when I get home. (I do carry spare connectors, but I hate messing about fixing things in work time, so I just switch the hose reel)
If it's anything more serious than that (such as a leaking hose) it gets chucked. Never would I spend my time messing about gluing things together. Replace it.