Would any one be able to suggest if the two lines running in and out of vacuum canister are specific or random? IE does the vacuum hose from manifold (source of vacuum) use the larger or smaller orifice on the canister? I don't remember when I took it apart.

Thanks

The manifold vacuum source should be the larger of the 2, the smaller is for whatever you are supplying vacuum to.

My car is plumbed just as the good Dr, says, Before you install, this is the time to make sure it is working as it should. To test the valve block off the small port and hitch up your Mighty vac. or your brand hand vac. pump to the large side and create a vacuum and then release using the vent on the gun. The valve in the top of can should allow the can to hold vacuum, this also will test the structural integrity of the can to make sure you aren't creating a vacuum leak by installing.

Will hook up as you said. Thank you Dr.

So when I test it, how do I know it is holding vacuum? Haven't used a pump before, but I see they have a gauge.

Do you have recommendation for a vacuum pump? I see Harbor Freight carries some, Amazon, too.

I should have tested it before I attached the fender, and also all the components downstream of it.

Thanks
Joe

67 Firebird 326, convt, a/c, auto,

A harbor freight pump will probably be fine for a Hobbyists. To check it out just block the hole with your finger pump it up and make sure the gauge does not bleed down. it is a great tool for bleeding brakes by your self checking choke pull offs, Dist. vacuum advance dashpot, auto trans vacuum modulator and many other things. Normally you would watch the gauge when testing the canister but because of the check valve you have to vent it and pull of to see if it is working. when bad you will hear the hissing noise of the valve leaking. If you hear nothing let it sit for 10 minutes and pull the cap from the small nipple and you should hear the hiss of the air rushing in to fill the canister through the small nipple. And yes it would have been easier when out on the bench, it is buried under there. On second thought if you make a pull on the small nipple with the large left open the check valve should hold and then you can watch the gauge.