Couple of things. When was the last time you followed the annual maintenance outlined in the Winegard manual? The procedures help reduce or eliminate the leaks that may come from the handle which may have nothing to do with sealant. There are rubber parts that need lubericating with silicone spray to prevent them from drying out and leaking.
Second I once took my older mh to get the roof resealed and was told that since the roof was both old and epdm that they DONโT remove old sealant as the process may damage the roof. Instead they just add new. Dicor and Cool Seal make products that may work.
Third, have you had the roof AC serviced lately to include checking the seal? There is a large seal/grommet around the bottom of the AC that may need to be adjusted by tightening the four bolts that hold the AC in place. By tightening the bolts you compress the seal assuring a good seal.
Tom Wilds
Blythewood, SC
2016 Newmar Baystar Sport 3004
2015 Jeep Wrangler 2dr HT