• 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.

72 AC Vacuum line connection and routing

Robliepse

Well-Known Member
Local time
4:54 PM
Joined
Apr 13, 2014
Messages
463
Reaction score
278
Location
Buford ga
I'm trying to figure out where I should connect the AC vent control vacuum line on my 440. I also need to know where the vacuum line goes through the firewall. The AC is one of the final parts of my 5 year restoration project

AC Lines.jpg lines 2.jpg
 
The hose goes from the vacuum tee on manifold through a grommet between brake booster and driver side inner fender. Same grommet used for the heater valve cable
 
On a ’72, the hose passes through a hole below the A/C fan opening, near the A/C box drain on the passenger side. Large grommet molded to the original vacuum line. The connection would be at the same manifold fitting as the brake booster.
Firewall.jpg
 
Last edited:
I have been searching this topic for months!
On my 72 Charger with A/C a vacuum hose runs through the same grommet as the heater control cable. it is connected to the small port at the brake booster fitting and feeds the HVAC control head.
I think the one under the A/C fan is for models with vacuum controlled heater valves. the firewall shown is a e-body. I studied that same picture.

20190517_182748.jpg 20190517_182755.jpg
 
Last edited:
Here is my 72 Charger firewall.

Capture.PNG
 
Confusing thing is on my car, the grommet under the A/C box appears it had a hose through it at one time. pic is from inside the car.

IMG_20180218_122012.jpg
 
The ’71-72 B-body firewall, inner fenders, and front frame rails are basically the same stampings as ’70-74 E-bodies. The holes used varied a bit depending on equipment. The picture posted is the same as the ’71 & 72 B-body. The labeling is accurate for A/C cars with one exception, shows three small screw holes around the grommet hole for the A/C vacuum supply, never seen that.

So, two Charger guys indicate the vacuum supply line combined with the water valve cable, never seen that way from the factory.
BTW, the original water valve cable hole is about a ½” in size, no way it would allow a vacuum hose to pass through with the original cable in the same ½” hole with a grommet.
20190517_200425.jpg
 
Last edited:
Well sir you are correct, I just went out and checked and there is no way that grommet will fit in the correct hole. I had it in the larger washer hole before and it was loose, solves the mystery for me.
Thanks for the info and correcting the wrong information.
BTW, the grommet part number is 3431279. its a Mopar number for a vacuum harness.
 
So, two Charger guys indicate the vacuum supply line combined with the water valve cable, never seen that way from the factory.
BTW, the original water valve cable hole is about a ½” in size, no way it would allow a vacuum hose to pass through with the original cable in the same ½” hole with a grommet.
View attachment 768107

Well on my 74 is like that and a 73 of a friend of mine the same. Maybe a 73/74 diff with 71/72. Never have paid attention of that on my buddies 71/72s actually
 
Well on my 74 is like that and a 73 of a friend of mine the same. Maybe a 73/74 diff with 71/72. Never have paid attention of that on my buddies 71/72s actually
What hole does it use?
 
My car? The one I’m describing, a hole between inner fender and brake booster. And the same grommet you shown on pic carrying heater valve cable and vacuum hose for the AC actuator system

Charger 74.

The hole for manual washer is unexistent on 73/74 because all were electric. And cruise control hole is on a diff location too. My car gets there the AC harness ( 74s run those out of the bulkhead )
 
Last edited:
Found this grommet, installed it next to the speedo cable, fits perfect.
Thanks 72GTX.
Now where does that pesky hood release cable go?

20190518_143629.jpg 20190518_141342.jpg
 
Last edited:
The ’71-72 B-body firewall, inner fenders, and front frame rails are basically the same stampings as ’70-74 E-bodies. The picture posted is the same as the ’71 & 72 B-body. The labeling is accurate for A/C cars with one exception, shows three small screw holes around the grommet hole for the A/C vacuum supply, never seen that.
View attachment 768107

I have those three holes on my car. When I took it apart, I wanted to make sure I kept the grommet and screws together because that grommet isn't repopped anywhere that I know of. They go, at least one if not both, to the vacuum can under the battery tray on my '71. That is, if memory serves me right :)
 
I saw another picture with the holes, sounds like the ’71 A/C two hose grommet is secured with screws. None of my ‘72s with single hose grommets had screws or holes. Yea, the ’71 A/C with a vacuum actuated water valve also had a vacuum reservoir under the battery box. The ’72 and later, with a cable operated water valve, did not.
 
I saw another picture with the holes, sounds like the ’71 A/C two hose grommet is secured with screws. None of my ‘72s with single hose grommets had screws or holes. Yea, the ’71 A/C with a vacuum actuated water valve also had a vacuum reservoir under the battery box. The ’72 and later, with a cable operated water valve, did not.
What hole does that cable use?
 
Thanks, on my way to garage.
maybe its covered by the insulation.
 
Auto Transport Service
Back
Top