Vacuum line mystery - Help

[finadk]

I bought my 76 as an unfinished prject and am finishing up the little details before starting it for the first time. The engine was changed has a 327 from a 68 camaro and some of the little things like vacuum line fittings are not all there.
There is a small hard plastic line that comes from inside the car and exits the firewall behind the distributor there is a vacume line about 3 feet long, long enought to reach over to the radiator, but I have no idea where it goes can anyone help?
Thanks,
Scott

 

[71LS5]

I'm not a '76 guy, but you, may want to try Doc Rebuid to get a copy of his vacuum line chart. It is an excellent source to show all the lines in the vacuum system Also if you don't have it already, I suggest a copy of the Assembly Instruction Manual (AIM) from Mid- America or one of the other Corvette suppliers. Good Luck.

 

[Bob Chadwick]

That line sounds like the line that goes to the vacuum controlled valve in the heater hose that controls the hot water going to the heater core. Check it out on this vacuum diagram.

 

[finadk]

Thanks,
It makes sense that it is the hoes that goes to the heater hose valve, unfortunatly the valve is missing on my car but the length of the hose is probably about right.
I looked in the assembly manual but could not find it, i will have to go back and look again.

scott

 

[Tatyana]

If it is the heater valve, be careful because it's probably very fragile.

 

[LIRacer]

Does the small hard plastic hose have a brass fitting at the end? It could be the oil line that presurizes the oil guage. It goes from the oil gauge through the firewall exitting at the distributor and connects to male fitting behind the distributor. If that is it DONT STAT THAT CAR WITHOUT CONNECTING IT! You will have oil everywhere. Also, that line is quite brittle and my be broken also at the oil gauge so check it there too to save your interior.

 

[Bob Chadwick]

I'm not 100% sure but I think by 76 the oil presure was electrical. I know it is on the 77.

 

[Scott Winebarger]

thanks for the vaccuum diagram , having a little problem with my a/c blowing out my heat vents ... maybe this will help, glad i found this site .. ty again

 

[Bob Chadwick]

A lack of vaccum will cause that as will a bad control head and/or actuator.

 

[finadk]

Thanks, I am now pretty sure it goes to the herater control valve that is missing. I plugged it up for now until I break in the new motor.
The oil pres on the 76 is electric.
scott

 

[Scott Winebarger]

haha , i found a heater control valve with no vaccuum line , go figure ...lol... time to start tracing