I also got a brass fitting , but it chewed up the plastic in no time , what you might find is that the fitting on the actual reel has worn and needs renewing , or it could just be the rubber o ring on said fitting , dont forget , these things do a crazy ammount of revolutions per day , they are gonna wear !
If i ever have a prob with leaks or pressure loss , the first thing i do is check all the o rings on all the connections , 90 % of the time this is the problem , when i think back to how many times i have ripped the system apart trying to find the fault , and it always turned out to be that poxy little dough nut of rubber !
Rich P @ F