WEll, I got the charcoal cannister out and there is yet another cannister underneath with various hoses and attachments to it. What function does this perform and where do the hoses go? Also, there are 2 valves next to it , one is hooked up to the A/C hoses and the other I am assuming is some type of heater control valve. The bib is corroded and the hose is detached. Please confirm if this is for the heater
Got a pic? If it has 2 small hoses going to it it is a vacuum canister. There is a valve on one of the heater hoses on a factory ac car. It shuts off water flow through the heater core when using the ac. Makes it more efficient.
so what is the function of the vacuum cannister? All of the hoses etc. are toast from sitting for years. I will try and trace the routes and replace them one by one. Does this have any function on the engine itself or is it for accessories?
You will need the vacuum canister if you want your inside heater controls to work. Otherwise.....they will default to defrost only.
Do you have a photo of the vacuum lines. I am having the same questions. I replaced my 250 with a 302 and removed the A/C. Now I'm not sure where the vacuum lines go.
Here is the layout for factory AC cars. The 70 has a metal vacuum switch and the hose layout is upside down compared to the 71 and up plastic switch. But they can still be interchanged just by flipping the hose plug.
Check your vacuum canister, they are bad for leaks around where the hoses go on (the plastic part) I had alot of trouble with getting my car to idle properly, and that was the cause, National PAats Depot has a reproduction for Mustangs that is a close fit.
I find that the vacuum canister leaks around where the check valve goes into the "can" as Dave noted. Just a little silicone around the outside edge to seal it up works fine. Use black silicone and it will be an invisible repair.
