If it's just needing to be re-caulked, FR recommends a caulk manufactured by Silaprene. Most dealers stock it or it can be ordered through FR's parts department.
If the front cap is beginning to seperate, I would use about anything for now as a temp fix just to keep any water damage form happening, then I would take it to a repair shop to have them check it out. There would be a reason why the front cap is beginning to seperate and I would think it will only get worse with time.
Gary & Trish
"PT Crew Member Since 11/2010"
2017 Prime Time Crusader 315RST TE 6.0 : 2007 Flagstaff 206ST MAC Series
2012 F-250 Lariat : FX4 : CC : SB : 6.7L Diesel : 3/55 Gears
2016 Nights Camped - 9