danalex

2001 CTD; mostly stock..mostly..
170K miles

Recently noticed a musty smell. Tracked it down to water underneath the passenger-side carpet.

It's not anti-freeze...coolant level is great and the water is clear.
Pulled back the carpet and water is pooled.
Apparently it is draining from somewhere up under the firewall...the carpet and pad are soaked...but the upper pad-barrier (higher up the floorboard)(not sure what to call it) is not soaked thru...just the bottom/frame side.

Looked inside the engine. Passengerside firewall. There is a tube protruding into the engine compartment. Water droplets are at the mouth of the tube, but not draining "out" into the enginebay then to ground.

Any ideas/hints as to where the water is coming from? Originally thought it might be a/c condensation....could be this, but not sure what the a/c lines look like behind the wall.

Could that tube be blocked/plugged? If so, is it more complicated than just poking something in the tube to dislodge blockage...(haven't tried yet).

Live in South Texas...haven't had rain in over 3 months, so I know I haven't driven in any puddles...

A good diagram or picture/video showing "how to fix" would be nice...

patdaly

Laugh all you want, but try putting a 9/16 or 5/8" short heater elbow hose on the AC drain tube, point the elbow down obviously.

For whatever reason they will take to not draining, mine started a couple years ago, just out of the blue, I tracked all the usual suspects, sealed the third brake light, checked with water, etc...... finally stuck the elbow hose on and dry as a bone since.

I want to say I stuck a 5/8 on mine, used a bit of silicone to make sure it stuck.

SIXSLUG

That^^

danalex

UPDATE: (not laughing)...

Left the truck doors open most all day today..trying to dry out the carpet and pad. I suppose even after they dry, they will likely have an odor...

1. hooked up a shop vac to try to suck out residual water...got a few droplets
2. dug up several hose pieces with intent to fit onto the drain tube.
3. decided to first try to "bend" the tube downward. mistake
..snapped off the plastic tube...
4. managed to wedge a piece of fuel-hose tube (maybe 3inches long) into the hole where original one was... (added some gasket-adhesive first before inserting it). hose is long enough to angle downward.
5. Took truck out for good test drive; a/c full blast
6. Upon return, crawled under--water is dripping out the tube.
7. Looked on floorboard. I think the upper floorboard covering is still wet ...but not soaking or draining out.
Summary:
a. Don't try to bend the plastic drain tube !!!
b. going to have to wait for everything to dry out really good before I declare success.

Question: If it becomes necessary to get at the actual leak source, how do I go about that (any instructions?) ?

SIXSLUG

Are you sure it's not anti-freeze?

patdaly

Fooey, I thought I had a picture of that area, but I don't. Basically to fix it correctly you will need a different heater box, specifically the lower half, but yards are full of them now, so I would just get the whole assy. Essentially the housing slopes down to the floor and the round tube is molded to the box. You might be Ok with the fix you have, just have to see if she leaks.

danalex

1. Not antifreeze
2. Heater Box: if I need one, what years are all the same? I have the 2001..wondering if other year(s) will work if I find one in a "yard". also, do they have to come out of the diesel 2500? or, can I use one from a gaser? (same?).
A. if i need to replace the heater box, what else do I have to remove/disassemble in order to do the swap? ((easy? ))

Drove the truck to work today. Appears I still have some drainage to the floorboard, so I suspect my "shove hose in hole" didn't completely fix it...

patdaly

Boy, exact year interchange is going to be tough, looking thru the parts books, the parts look almost identical, but there are part number differences at least between a 97 and a 02. The rest of the parts look identical except for the 02 uses a servo motor temperature control. I would say stick with a 98 to 01 for 1500 box, you can go to 02 for the 2500 box ( it was a weird transition year thing ). Gasser or diesel should be the same.

As for swapping parts, basically pull the dash and remove the whole assy, if you are careful you can just remove the pass side and strap it up while you pull the heater box assy.

One other thing, here is a view of what that area looks like, it is down at the bottom and on the inside of teh cab, so you might be able to pull the carpet away and inspect the box for cracks, etc.

I hesitate to mention it, but a solid coating of Silicone would seal it off and direct the water out........

danalex

Thanks for the diagram!

I like the silicon idea ...not sure if I quite understand tho.. how would it drain (and where would it drain?)

The tube snapped off in a way that I'm fairly certain I could "Goop" it back onto the housing (I love Goop).

Pulling the dash sounds challenging...disconnecting wires and cables doesn't sound fun (traumatized by snapping off a speedometer cable yrs ago on a different vehicle)

Thanks also for the YEAR/MODEL guidance for a replacement box. ((if I wanted to purchase NEW, I would technically ask for a "HEATER CORE"--correct?))


d

Busboy

Pat has you on the right track, the heater Plenum is what you need but I would not buy new as there must be lots in the wrecker. They are the same up to 2001 with the electric blend door motor, the very early ones 95possibly 96/97 had a cable operated blend door. If yours was working well it would be easy to transfer all the good bits over and clean out the heater core and evaporator, I might add if you plan on keeping the truck it might pay to just get new heater core and evaporator as the AC will have to be discharged anyway.

patdaly

Essentially, if you look at the area I circled, that is where the tube comes thru the floor to the outside at the bottom. There is a seal, index 20 that seals it up from the elements. I guess what I am saying is a redneck fix would be to have it the way you fixed it, but additionally go inside the truck where the drain meets the floorboard and put a bead to keep it from running inside the truck.