'93 GMC K1500 long bed supports
 

I have a '93 K1500 long bed that has a bed liner and someone had used a pitchfork to clean out mulch from the bed. I have teeny holes that leaked water directly onto the front bed support or crossmember. The holes in the bedliner have been sealed but what should I expect from the water that was dripping into the cross/member piece? The bed was pushed into the cab years ago so access is limited. I used a funnel with a short hose to dribble por-15 into the support but am not sure it is enough. Anyone else had this situation?