RV Repair: roof repair, rv supply store, class c rv

Question
I have a 1984 Triple E 21 foot class C RV. there are drips of water dripping from both the roof vent and the airconditioner. For now I will patch around them but would like to tar the entire roof because I don't know the exact origin of where the water is getting in. Do you recomend any particular product and does all old caulking have to be removed first?

Answer
I hope you are not serious when you say you are going to "tar" the roof.  Many RV roof coatings are made, most are rubber based and made for just that purpose.
If it were mine, I would do it right the first time.  Remove the air conditioner and roof vents, buy caulking tape from an RV supply store, clean the surfaces, apply the new caulking tape, torque down with new screws in new holes and your leaks should be solved.  It's not necessary to coat an entire roof if it is solid.
The best alternative, a new rubber roof.  They come in a kit, are easy to apply, relatively inexpensive and will last longer than you or your coach will.  Good luck.