70 Challenger with factory AC

While working under dash, noticed this small part had broken off at 1 end.
I’m guessing it’s some sort of vacuum check valve?
It’s small maybe 1” long with tiny 1/8” fittings.
It’s connected to the vacuum fitting on the back of the AC control switch.

What is it, what does it do, where to get another?

if you can find the rest of it in a vacuum line you could try super gluing it back on.

Agreed about gluing the nipple back on.

I believe it is a pneumatic dashpot (dampening device) which slows the actuation of the flapper inside the heater box.

Believe it has a very small orifice for the vacuum. While you need vacuum to control the a/c switch, you don't want a "large" opening to create a vacuum like leak.
Guess kinda like a vacuum regulator.

I might try glueing it back together, but I think it broke because its dry rotted.
Assumed it was a check valve because of the large center section, never thought about a orifice/reducer.

Anyone have a parts book?
This thing had to be on every car with AC, with the PN maybe there's an aftermarket replacement ?

Thx

You can have your own

https://mymopar.com/parts-manuals/

Vacuum ck valve. Keeps the heater ac doors in place on hard acceleration.

Was a tsb part back in the 80s and 90s.

Don't believe it's factory in the muscle car years.

My former 1970 challenger didn't have it

If it's just a check valve, then DORMAN 47149 or 47170 may work.

I agree a check valve..


Most GM's and Mopars now use electric doors instead of Vaccum powered doors.

If you aren't worried about OEM Ford still uses them on many cars and are plentiful in junkyards.

I regularly hit a junkyard and pick up 4 or 5 to stock up on them. 5 in my local junkyard is half the price of the one new one.

Ford puts them under the hood and are easy to get to. Find the vacuum lines on the intake and follow the one going back to the dash. Should be pretty evident.

Trucks, vans, and full size especially but often on the smaller cars too.

You will have to adapt them down. The 70's dodges had smaller lines than the newer ford check valves.


On a side note; If you go new, Dorman had a lot, and I mean a lot, of bad valves get out. Open the pack and blow through the valve both ways. Air should only go one way. I went through 6 packs to find 1 good one last time I bought a new one.

Check valve does make sense.
I'll probably try the Dorman, nearest JY is over 1 hr away.

Next question, which way should it flow?
Arrow towards switch to let air in and not leak back out?

No idea where all the vacuum lines go

Thx

Air should flow towards the engine.

So if you can blow into it and air passes through, the end in your mouth is the end to the controls and the other end goes to the engine.

There should be a fitting behind the carb with the brake booster hose on it. It will have a separate small port for a hose that goes through the firewall to the check valve and then to the controls.

You may check that hose also to be sure it is still good. Age gets to them a lot.