The only thing I used on my Ranco heater valve was plumbers grease during reassembly. Greased the seal and tube lightly to help insert it back into the tube. Plumbers grease will not deteriorate the rubber seal.

Tim


"Pay attention to the details! It ALWAYS pays off."

1949 Chevrolet 3100 Series 1/2 ton Pickup
1964 Chevrolet C10 (Ol' Yella) (SOLD)
1958 Chevrolet Biscayne 2 door (SOLD)
1970 VW Beetle