For RV Window leaks between the frame and the side wall
1. Remove the screws from the window frame on the inside. Be sure have a helper hold the window on the outside of the RV.2. Remove all the old butyle sealant from both the RV sidewall and the aluminum window frame.3. Clean and clean it again. Physically remove as much of the old sealant as possible. Use a solvent like acetone or VC thinner to remove any left over sealant.
4. Check the frame for straightness... a bent frame will more likely leak again.
5. Lay the butyl rubber seal onto the back side of the frame. B. LAY the rubber in -- DON'T stretch it in place. You want as much body to it as possible, pulling and stretching it onto the frame will end up with a thinner seal with less butyl "meat" to seal the joint.
6. Make the butt joint for the butyl rubber seal at the BOTTOM of the window. Just butt the two ends tightly--don't overlap the rubber. Make the seal just a LITTLE too long so when you butt them, there's a little pressure holding the two ends together.7. Put the window back in place and evenly tighten the screws to seat the rubber. Don't distort the frame, just an even pressure all around.8. Let the butyl rubber set overnight and wait to pull off the excess that oozes out around the frame outside. It's best done when it's cool weather outside.