Archived Passenger carpet wet can't find Evap Drain line to clear where is it

[CChinman]

Have had AC work done and now floor is soaked. Was told Evap line may be clogged. Opened hood, went under truck 1997 3500, can't find what I thought would be easy to find. Putting myself in report for being an idiot so seeking guidance. Thanks!

 

[BigPapa]

It is on the firewall directly behind the very bottom of the receiver/drier. Typically they don't get clogged. The pipe through the firewall is not angled down enough and the water runs back down the outside of the pipe and through the foam rubber grommet. Get you a piece of 5/8" heater hose at least a foot long and put over it. It will stay on without a clamp but you can put a clamp on it if you like.

I can post a pic if you need it.

 

[CChinman]

Please post pic. Thank u

 

[GAmes]

I used an elbow shaped spark plug boot.

 

[BigPapa]

Here ya go. Pic is from above, between the air filter and the firewall. Easiest to get to from underneath.

 

[CChinman]

Thank you. An AC shop said it could my heater core but every TDR and other cummins site references the Evac line. What is the heater hose for?, a new drain line? Apologies but I am learning the idiosyncrasies of these trucks. I don't want to deal with heater core as that will be costly and destroy my dash which isn't even cracked yet. Thank you.., C

 

[BigPapa]

An AC shop said it could my heater core....

It could be. Have you been running your A/C lately? If it's not been on in a while and your carpet is just now getting wet it could very well be the heater core or an exterior leak. Get you a clean paper towel and soak some of it up. Is it clear? Does it smell like coolant? Does it feel oily?

What is the heater hose for?, a new drain line?

The pipe through the firewall is not angled down enough and the water runs back down the outside of the pipe and through the foam rubber grommet. Get you a piece of 5/8" heater hose at least a foot long and put over it. It will stay on without a clamp but you can put a clamp on it if you like.

The drain in stock form is a plastic "pipe" that protrudes through the firewall @ 1.5". It is "sealed" by a sponge rubber grommet. The drain is not angled down but comes straight out. The water runs out of the pipe and then back down the outside of it and through the seal, onto your floorboard. With the hose in place, the water drains from the end of the hose and cannot go back into the hole in the firewall. The hose only needs to be long enough to have an inch or two of drop to it and not drain on top of something. I ran mine to where the end lays on the lower A-arm and drains on the ground. A piece of an old heater hose with a molded bend in it would be ideal.

 

[petersonj]

Scott, you are right on with your diagnoses. My wife and I are just completing a 12,000 mile road trip with a travel trailer. The truck (2002 Dodge ram) started showing the same symptoms randomly - sometimes the carpet was a little wet, then other times it was soaked. I stopped a an auto parts store and purchased a molded hose with a 90 degree bend - didn't care what the part was for - and placed it on the evaporator drain. Definitely solved the problem. It was tested well, since the last part of the trip took us into south Texas where dew points were consistently above 70 degrees.

As you said the problem shows up when the seal fails between the HVAC housing and the firewall. The water drains from the horizontal drain pipe, but then follows the outside of the pipe through the firewall and back into the passenger compartment.

Anybody with the wet passenger floor symptom should do this step first as it is an inexpensive repair and will probably fix the problem.

-John

 

[BigPapa]

Glad you got it fixed. Happy travels!

 

[CChinman]

Thank you all!!.....for the info. I will take a look at it tomorrow and see if I can apply my lame mechanical skills to the issue and solve the problem. The more I read the more I understand and I truly appreciate the expertise and experience within this forum. Hope you all have a very pleasant remainder of your weekend....turn your clocks back tonight!