I have a 68 that has the single port vacuum tank for the lights. It is rusty and leaks. I was given a working vacuum tank off a 67, but it has the 2 port vacuum valve. Can I use it? If so, do I just block off one of the ports?
The dual port can was used on early built 67 models (prior to April 67 I believe) It is a built in check valve, thus the two ports. I believe you can use it on your 68 by plugging the one port and using the correct port. Odds are the check valve doesn’t work anyway. But you will find that they typically end up leaking where the plastic valve is pressed into the can. Sometimes can be taken care of with epoxy or perhaps some other sealant smeared around that area. Your 68 should already have a check valve in line.
Thank you for the information. It looks like the previous owner of the tank already sealed around the valve. Do you happen to know which is the correct port to use and which is the one to be plugged? My lights are off the car right now for repair/paint so I cannot test.
You will have to put a hose on and see if one of them flows air freely both ways. If neither does then that means the check valve is still functioning. Do to the fact you already have an external check valve (or should have anyway) then you would have to render that check valve built into the tank useless by maybe drill through it. I have never done it, so not sure. I have a single port can here that came with my car and being my car is an early production 67 (Nov 66) it should have the double like you got. I’d trade you, but the shipping may not be worth it for either of us. Also I had to do some repairs to the mounting flange on this one, but I did a respectable job, and it passed a 15lb pressure test with soapy water.