For a 65 impala do I need a vented or non vented gas cap? 2- I have a non-vented on there now and it seeems like the tank builds a lot of presure.
If the cap is non-vented sould there be venting somewhere on the tank to releave the presure? It seems like there is a tube coming off the tank but it has a small piece of fuel line and is pluged with a bolt and a hose clamp. : :confused:

You would need to take a peek at the top of your tank (Iused a mirror and a flash light)to see the top of your sending unit. If it has one line coming off of it.......You will need a vented gas cap. If two lines come out of your tank.....non-vented. They claim if you run a non vented gas cap on a non vented gas tank............you could collapse your tank due to the vacuum.

I think(not 100% sure) the vent is similar to the Chevelle where there is a nipple on the rear of the tank and a short hose connected to a pipe that loops up into the trunk then and back down and has an open end. If this hose or pipe is plugged you will build up pressure. I have seen the vent pipes listed as a reproduction part.
Edit: I show the 65 and 66 Impala use the same gas tank and my 66 repair manual shows Impala vent pipe in rear of the trunk on the passenger side clipped to the inner wheel well same as the Chevelle.
Rene
66_Malibu

65,

Shooter has it correct. 65 Impala's - unless it's a wagon, use a NON vented gas cap. The tank is vented through the tube inside of the trunk - just as Shooter described.

Dan

Thanks Guys for your help. I just have to unplug that vent hose and run a new one the way it is suppose to go. Im going to use fuel hose with clamps rather than buy the reprduction metal tubing for $25. I figure it will work just as good.