Just a suggestion, go to your local hardware store and buy a couple feet of 3/8" ID x 1/2" OD clear Tygon tubing and a couple narrow 1/2" hose clamps. Cut the clamps off the tubing on the sight tube on the radiator overflow tank and replace the tubing with new. Use small regular gear drive hose clamps. Keep the extra tubing so that you can replace it every couple years as it yellows. Total cost only a couple bucks, but really makes a difference.