When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I bought a 1969 C3 and an trying to sort things one by on. There’s a wierd looking vacuum arrangement where the vacuum from the manifold come to a tee. From the tee one hose goes to the tee for the headlight/wiper vacuum. The other goes to a smaller vacuum hose that goes through the firewall. Does anybody know what this is about?
If you haven’t already done so, buy yourself an AIM for your year Corvette. It has some detailed diagrams that show the proper connections and routing of the vacuum lines. All Corvette vendors have them.
My guess here at the top picture. GM used a vacuum T with 2 large ports and 1 small port. They are fragile especially after 50+ years and the small port broke off. Looks like someone put in a 3 port T, a short piece of hose, and then a reducer fitting. Original T's are hard to come by and are not reproduced.
The line that tee's off and enters the fire wall provides all of the "interior" vacuum. There is a vacuum line to the head light switch and more to the override valves for head lights and wiper cover. More vac is used by heater controls. If you find where it comes through on the inside you will see that it splits off and serves several functions, or at least it does on my '69.
You're missing these two parts. The white plastic piece is a filter that goes in the line from the manifold. The metal "tee' device is a check valve. Without it, all your "saved" vacuum will bleed back thru the manifold when you shut the car off. Coming out of the check valve are two hose fittings. The larger one feeds your vacuum canister. This vacuum does the work of closing headlights and wiper door. The smaller hose goes thru the firewall, This vacuum feeds the controls... headlight doors, light and wiper door overides, and the **** that can "freeze' the wiper position. It can be confusing.
Vacuum hose question
