What Am I Looking At Here? - A/C & Vacuum Line T/S
Legend
Joined: Nov 2014
Posts: 8,098
Likes: 318
Moparite,
Thanks for the drawing. This is the diagram that actually caused me the greatest confusion between what's actually installed in my truck, as seen in the photo in the OP, and what's supposed to be there. On the basis of this diagram, I was about to go in and change out the downstream check valve; I stopped when I noted the reality/diagram mismatch.
Another day of rain is keeping me from pulling the cowl and looking at what's going on there.
@HeyYou, if that mini reservoir/check valve assembly was supposed to help with wild vents, it wasn't working well at all. Have had the wild vent issue since I had the truck, but only recently did the blower doors stop working altogether.
Thanks for the drawing. This is the diagram that actually caused me the greatest confusion between what's actually installed in my truck, as seen in the photo in the OP, and what's supposed to be there. On the basis of this diagram, I was about to go in and change out the downstream check valve; I stopped when I noted the reality/diagram mismatch.
Another day of rain is keeping me from pulling the cowl and looking at what's going on there.
@HeyYou, if that mini reservoir/check valve assembly was supposed to help with wild vents, it wasn't working well at all. Have had the wild vent issue since I had the truck, but only recently did the blower doors stop working altogether.
Thread Starter
|
Amateur
Joined: Jan 2018
Posts: 26
Likes: 0
From: Hampton Roads, VA
Happy Memorial Day to everybody! Update as fol:
It is indeed a check valve, Mopar part 4677204. Check valve has been verified functional.
It is inline upstream of the vacuum supply for ventilation control. The line that branches off from the T connection is for the cruise control (which, as expected, doesn't work either). Thus, odds are really good that this was the source of my problem.
Now to the business of finding the firewall penetration and repairing and replacing vacuum lines.
It is indeed a check valve, Mopar part 4677204. Check valve has been verified functional.
It is inline upstream of the vacuum supply for ventilation control. The line that branches off from the T connection is for the cruise control (which, as expected, doesn't work either). Thus, odds are really good that this was the source of my problem.
Now to the business of finding the firewall penetration and repairing and replacing vacuum lines.
Record Breaker
Joined: Jul 2014
Posts: 1,362
Likes: 35
From: Wisconsin
Cap this line and see if the cruise control works. What year and engine are your truck? If you have 4wd, it also gets vacuum from that line. Have you replaced the plenum gasket yet? It's a huge vacuum leak if it's bad.
Thread Starter
|
Amateur
Joined: Jan 2018
Posts: 26
Likes: 0
From: Hampton Roads, VA
So, my work life has been absolutely miserable since I last posted.
At least the internet filters at work let me access this site today.
Since I've last posted, here's what I've learned:
- The ginormous check valve is working properly.
- I obtained a hand operated vacuum pump to verify where the vacuum leak might be. Connected to the cruise control reservoir (located under the cowl), I was able to draw 25" of vacuum, with a 4" drop over 10 minutes. Probably not there.
- I was unable to draw any vacuum using the line to the HVAC system. Next step is to chase the leak inside the cab.
Sometimes where not to look is as good as knowing where to look.
More to follow.
At least the internet filters at work let me access this site today.
Since I've last posted, here's what I've learned:
- The ginormous check valve is working properly.
- I obtained a hand operated vacuum pump to verify where the vacuum leak might be. Connected to the cruise control reservoir (located under the cowl), I was able to draw 25" of vacuum, with a 4" drop over 10 minutes. Probably not there.
- I was unable to draw any vacuum using the line to the HVAC system. Next step is to chase the leak inside the cab.
Sometimes where not to look is as good as knowing where to look.
More to follow.