hello new to the forum, I've tried searching around before asking and haven't found anything. I have a 99 Dodge Ram Laramie 1500 with the wild vents issue, I've changed all check valves and it still does it. I've come to find out that the vacuum leak is behind the dash, pretty sure behind the glove box/radio. Anyway I can get to any of the vacuum lines without dropping the whole dash?

 

That's gonna be fun..... If you dash is still in one piece.... it's hard to get to the lines. You *might* be able to take out the glove box, and see something, but, don't hold your breath.

You can download a service manual for your truck from here.

Welcome to DF!

 

Thanks, I know I can get to some of the lines behind the radio but I know for a fact it's coming from behind the hvac system was hoping for an easier way. Of course my dash doesn't have a single crack in it, I'll keep one in the shopping cart to be on the safe side

 

It is not uncommon for the line going through the firewall to have a hole worn in it.
Carefully pull any slack towards the engine bay and look for chaffing.
Old lines tend to be brittle, so it may snap... it it does, try not to loose the end... if you do, you'll be back to pulling the dash.
If you have a stub to work with, make a joiner out of a piece of rubber hose... a light smear of silicone sealer on the outside of the line helps to seal and retain the joint when dry.

 

Spillage nailed it, I just removed dash and all to change a leaky heater core and found the vacuum leak while I was at it. It was exactly as described and I can see his technique working as long as you have patience. The vac line comes out amongst the air con piping.

Good Luck.

Oh, the dash comes out as a complete unit (plastic & metal structure) then the hvac box comes out...

 

Couldn't I unbolt the dash and instead of taking it completely out just roll it forward and hold it up with straps and look down inside without removing the hvac box? I know the hvac box is mounted to the firewall and I'm thinking I shouldn't have to disconnect any ac lines unless I'm removing the hvac box correct? The previous owner did a heater core on it days prior to me purchasing it, so I'm sure he hit a line in the process.

Hopefully it is that line that would be sweet! Thanks for input

 

You can try it. Worst that will happen is you will discover that yep, you need to pull the dash... Just tilting it forward *should* give you access to everything you need to see.

 

I was able to access most of the vacuum lines by just tipping the dash during a heater core replacement. I wish I would have replaced them all while i was in there... I did replace all the foam seals on the hvac unit and vents while i was in there.

 

All connections can be accessed without removing dash. You will need to remove the user control unit where all the hoses connect in the back. It's all 1/8 in hose. Get some 1/8 in hose couplers too. If possible use same color hose or same colored tape or markings.

5 hoses total.
Group A, Black and Green hoses are taped behind air box, just cut em and reroute new hoses
Black: from controller to engine bay(through firewall at heater core grommet)
Green: from controller to Right actuator(silver can, see pictures in my DIY)

Group B, these three hoses start at the controller and drop straight down to the 3 connections to the right of the gas pedal.
Red: from controller to Lower Left actuators
Brown: from controller to Lower Left actuators
Yellow: from controller to Lower Left actuators


Check out my heater core DIY in the help section for pictures.

https://dodgeforum.com/forum/2nd-gen...ml#post3308920

 

Wow thanks for that input, I was going to start behind there anyway but that definitely helps! Im almost positive it's the hose going through the firewall, I tried pulling any slack out of it to see if I can find a hole and there is no slack what so ever and it's only a good 2 inches out from the firewall. I'm guessing the previous owner pinched the hose while installing the heater core