I was taught by a very old school mechanic many years ago that grease is better than adhesives for O-rings, gaskets, seals etc. Have always used it even on carb and cooling system gaskets. If the mating sufaces are true I have never had a problem. The best part is when you take something appart later that had been assembled with grease instead adhesive or sealer, you don't ruin the gasket, seal or o-ring and can easily reuse it.