Hi GuysI need some input. I installed a Stewart Warner mechanical oil pressure gauge a couple of weeks ago. I used Polyethylene tubing and compression fittings from Lowes. Specifically, I used the compression fittings with the brass collars. Delrin collars were also available. Last Saturday, while leaving to go to a cruise, the car spit the tubing out of the compression fitting and promptly pumped 3 quarts of oil everywhere! I don't want to experience this again! I'm trying to determine what I did wrong, (which may include just having the fitting too loose!) So, if anyone has information / experience regarding the use of copper V/S plastic collars on these fittings please let me know. Thanks in advance for all input, it is highly valued.Lyle63 Plymouth Sport Fury 383 4bbl.