HVAC Vacuum Reservoir
Thread Starter
Pro
Joined: Sep 2000
Posts: 703
Likes: 0
From: Cowtown
HVAC Vacuum Reservoir
Due to air delivery problems, I decided to attempt the diagnosis myself. Upon inspection of the vacuum reservoir, I found three lines, one of which is corroded and cracked and appears to be the engine vacuum line. I know where the second line goes.....where does the third go? The service manual only indicates two vacuum lines.
Unfortunately, the engine vacuum line split somewhere between the manifold and reservoir and I am unable to find the other end. Could someone tell me where the other end is on the back of the manifold?
Thanks in advance.
Unfortunately, the engine vacuum line split somewhere between the manifold and reservoir and I am unable to find the other end. Could someone tell me where the other end is on the back of the manifold?
Thanks in advance.
Racer
Joined: Aug 2004
Posts: 438
Likes: 15
From: satellite beach fl
Vacuum line comes from MAP sensor on the firewall side of the intake, right hand side, large brake boost line also comes from the MAP. The third line goes to the secondary air solenoid mounted on the right hand frame between the top of front fender and frame, fastened by one bolt, very hard to see.
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
The tank has three fittings One goes to the HVAC controllers inside the passengers foot well:
one is the vacuum supply line from the back of the manifold:
The other one goes over the the AIR pump which is located under the drivers side head light assembly:
Bill C
Melting Slicks
Joined: Mar 2001
Posts: 2,482
Likes: 0
From: Worden Illinois
Originally Posted by Speedway
Thanks for all the help. I'd sure like to know who the genius was that decided all critical components should be placed under a battery. No brain no headache I suppose.
I am making the same repair to my 98 coupe, I found 2 of the vacuum lines cracked on mine. Good luck with the repairs. 
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,595
Likes: 4,055
From: Cape Coral, Florida
Didn't you just post your issue in another thread ??…which one do you want deleted ??…as I mentioned you should not be seeing psi…vacuum is read in inches of Mercury..and yes if your manifold vacuum is 18-22 inches you should be seeing that !!
Last edited by C5 Diag; Oct 3, 2021 at 09:02 PM.
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