Today's Canada Day so I celebrated it by working on my car. I'm adding A/C to my car. It got up to 100 F this week. So I pulled out the remaining parts from my heater system and prepped all my A/C parts from a junked car for installation.

My Helm's manual is very thourough on the wiring and part installation, but I can't find out where the vacuum source is for the system. The vacuum tank mounted on the top of the firewall just left of the windshield wiper motor (I think) gets a vacuum from the engine somewhere. Can somebody tell me where it's supposed to be from?

I have a 305 with a 4bbl carburator. Anybody else have this engine with A/C and can trace the vacuum line to the engine for me? Thanks!

 

Well, that sounds like the power brake unit. Are you looking for a vacuum source to operate the A/C controls ??

Auggie

 

Yeah, I'm looking for a vacuum source for the A/C. All early thirdgen A/C cars had a vacuum tank with a check valve mounted on the firewall to supply a vacuum. It has two lines, one runs to the A/C controls through the firewall, the other gets vacuum from the carb or the manifold or somewhere else.

The vacuum source is what I need to know.

 

Well, I have a 1984 Z28 and I went out and looked for that vac. tank and I don't have one. I looked in my Ser. Man. and it does show a vac. tank mounted right next to the vac. brake booster like you said. I bought my Z new so it didn't have a tank. The Ser. Man. seems to say that the tank was for 6 & 4 cyl eng's ??? The vac. source for my A/C & heater controls is located behind the carb. There is a silver 90* elbow screwed right into the int. manifold runner. I hope this helps some.

Auggie

 

I have your same set-up and my tank is right where you said it is, the vacuum source is routed to a fitting in the mainfold between the carb and the dist. it looks like a elbow with about a 3/8" fitting that screws into the manifold and about a 1/8" barbed fitting the the vacuum hose hooks to.

 

Would it be the same for '83 CFI?
Will

 

Old thread response. But I will answer in case someone else is looking for the info. Yes, the '83 CFI had the same vacuum tank mounted on the firewall. Vacuum was sourced from the intake manifold, almost the same location as the carb models.

 

You have adrawing of the routing to the hvac system? Colors of hoses, etc?
I'll take a picture drawn out on a piece of paper. I just need how to route it.
Thanks,
Will

 

Not much in the factory service manual or parts manual.




Vaccuum Source Hose (#10) goes to the vacuum port (bottom) pictured above.

 

Thank you, it's a good start. Which book is this?
Will

 

I purchased a Factory Shop Manual (not Haynes or Chilton's) from a vendor on eBay. That is where the picture above originated.