120inna55

RE: 1998 Trans Am (non-WS6) LS1.

I've scoured these forums and can't find a diagram that makes sense to me. I've had rodents under my hood (long story). My AC won't blow air through the front vents, but it blows cold air under the dash, at my feet, and in the defrost vents.

I figured out it's a vacuum leak. I closely inspected and found a disconnected/orphaned tube. The rodent chewed the rubber connector but really didn't do much to the hose itself (as far as I can see). I tried to take a pic.

Coming off this valve-looking thing, one hose leads to the front of the car and is bundled with other wires in one of those corrugate tubes. The other hose is the one that's disconnected. It was leading towards the firewall, but my fat hands can't find whatever it was supposed to connect to. Does it join to another hose way back there? I can't find another dangling hose, but that doesn't mean it's not there.

I'm not a mechanic. I really just want my AC to blow in my face. Is this something that just takes persistence in finding its origin or do I need to just take it to a mechanic? If so, is this going to be some incredible amount of labor requiring major disassembly?

In this pic, I'm on the passenger side right up against the windshield. I worked the hose up into the light and I'm peeling back the rubber part that got chewed:



Here's the "valve-looking thing" I referred to. I don't know what it's called. I'm just posting the pic as a point of reference. It's not hurt. It's where the hose in question originates. I need to know where it terminates.

Majestic9C1

iTrader: (19)

do you only see one side of the open hose or both sides??

one of those hoses goes to the back of the intake manifold...

If the rubber connector is missing just get a new one at the local parts store.. in the correct size

120inna55

I'm not understanding your question. One end of the hose is secured to the valve where it belongs. I'm holding the other end---the free, chewed end in my hand in the pic. Yes, it's actually the rubber connector that's chewed, the hose itself is fine. The problem is, I don't where on the back of the manifold it belongs. Even if I could get my hand back there, I don't know what I'm feeling for or even approximately where it goes.

JOHNNY59

iTrader: (398)

Can't tell from the picture, but one of the plastic lines run to the vacuum canister in the front of the car.

120inna55

Yep, that one's ok. It's the one going towards the firewall that I don't know where to connect it. @Majestic9C1 says it goes to the back of the intake manifold which makes sense because that's where it was dangling. Is this some place I should reasonably be able to reach with my hand without removing the manifold?

Spartan7

iTrader: (7)

http://shbox.com/1/vac_check_valve.jpg

Majestic9C1

iTrader: (19)

it plugs into the nipple on the map sensor housing below the sensor itself

120inna55

That's useful information. Thanks! Hopefully I can get my meaty hands back there once I get a replacement rubber connector.

wssix99

iTrader: (5)

My hands were transplanted from a large gorilla and I was able to reach deeper to change out the oil pressure sender.

I magnetic inspection mirror and a good light make this a snap. You can place the mirror on the cowl to give you a good view of the backside of the engine while you are feeling around back there.

RockinWs6

Easiest way to remedy this is to attach a long piece of vacuum hose to intake nipple then attach the other end to the plastic hose.

120inna55

Ok. A little change in the problem.

Given the length of this hose, there's no way it would reach the back of the manifold. The hose itself has not been chewed in two. The rubber connector on the end is what's partially chewed just enough to let it fall away from whatever it was connected to. The end of the hose that's free is a clean cut, i.e. manufactured length.

Here's the pic Spartan7 posted. It says it's for a 95 Camaro:


If this pic is accurate to my 98 TA, then the hose that's disconnected is the one that allegedly goes to the "mode selector on the dashboard", not the one going to the rear of the manifold. There's no way this hose will reach that far anyway. Yet, it's plenty long enough to make it to the firewall as long as it stays in a relatively straight path. So, is there a nipple on the firewall itself in this vicinity? Or does the hose from the mode selector snake through the firewall and then joint via the rubber connector on the engine side of the firewall? I really appreciate the help, guys.

Cool28

iTrader: (2)

I had mine come off. You have to feel along the firewall where the pcm is sort of. If I remember correct it just pushes in.

120inna55

So there's a hole or a nipple coming right off the firewall?

98CayenneT/A

Here are some pictures I took for ya

120inna55

That's it! I can at least see it now. There's just a nubbin' of rubber protruding from that. I can barely touch it. I'll have to move some wiring harnesses when there's more daylight, but no point until I have what I need to fix it. That rubber part that's in the firewall, where do I find one? How does it connect? The last thing I want to do is push the connection on the other side of the firewall through.

Thanks to all your help, I'm getting closer, but I still need some guidance.

98CayenneT/A

It should just push on snug. It's a vacuum line so it's not like it needs a clip or connector to stay on to keep it from blowing off. A snug fit along with vacuum is how it stays on.

120inna55

But, if I pull the rubber nub that's remaining on the firewall, is there not a tube that continues on through to the mode selector in the dash? When I remove the rubber, what's to keep that tube from falling on the other side of the firewall?

98CayenneT/A

If I'm not mistaken it's like a hard rubber grommet that is pushed into the firewall with a nipple for the hose to push on to. You will be fine, just give a slight twist and pull to get the boot off and a slight twist and push to get the new line back on

120inna55

Ok, let me ask this another way. When I pull that grommet from the engine side of the firewall, is there a line on the other side that will fall down within the dash? Will the line that's in the dash have slack and pull through with the grommet? The remainder of the grommet that's still there is not quite flush.

Majestic9C1

iTrader: (19)

no.. its held in place by the other side of the rubber grommet