Friggin' leaks!!!

movietvet said:

Ok, I get that it is a PITA, but I am really confused about what "future maintenance" would be for that area?

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Heater core replacement.

IMO, that is a repair and not a maintenance item.
Maintenance and repairs are two different things.

movietvet said:

IMO, that is a repair and not a maintenance item.

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True but some people might not. Only OP knows how they define maintenance.

smdk2500 said:

True but some people might not. Only OP knows how they define maintenance.

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If you guys say so.

Scooterwrench said:

some of the older cars and trucks had a sealer where the seams meet

Anybody ever dealt with this problem?

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Not recently, but I've played with my '88 over a decade ago, and other vehicles beyond that one.

docstoy said:

If it isn't cracked just apply either the oem butyl caulk or silicone sealer,

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NOT RTV Silicone!

Scooterwrench said:

Yeah I was hoping to not have to resort to sealer that would make future maintenance a PITA.

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Agreed.

docstoy said:

Silicone will be easier to remove,

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RTV Silicone will be a DISASTER to remove.

Scooterwrench said:

I'll be gluing up the seam with something. Maybe I can find that seam sealer they used to use in the 70's and 80's

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Two Words:

ROPE CAULK.

Comes in multiple colors, from several manufacturers. Available at any hardware or "home improvement" store, or from Amazon. Easy-on, easy-off, non-messy, not expensive.

Example:
www.amazon.com/Frost-King-B2-Caulking-19-Ounce/dp/B000LNODSQ/ref=sr_1_5?

Schurkey said:

Two Words:

ROPE CAULK.

Comes in multiple colors, from several manufacturers. Available at any hardware or "home improvement" store, or from Amazon. Easy-on, easy-off, non-messy, not expensive.

Example:
www.amazon.com/Frost-King-B2-Caulking-19-Ounce/dp/B000LNODSQ/ref=sr_1_5?

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Thanks Shurk!
That's what I was thinking of. It was black in the older cars but gray will work just fine.

In normal operation, there's no need for sealant between the cover and the box. The evaporator core lives in its own section of the box which is sealed away on its own, apart from the cover under the heater core. The plastic nipple for the evaporator drain is not "open" to the heater core area. Forgive the low quality pics; took these in the 1.2mp days. Note the evap drain:


In this pic you can see where I've split the housing open and IIRC there is some butyl seal between THOSE pieces (you can just barely see it peeling away towards the core.) BTW in both of these older small pics you can see the firewall seal which is the thick piece of foam rubber; it's known for deteriorating by this point.


With all that said...

The only scenarios I can see where you would leak evap water from the heater core cover would be:
1. broken a/c box in the evaporator core area

2. heavily sweating evaporator core area PLUS broken heater core cover

3. failed seal between the firewall and a/c box PLUS missing rubber elbow on evap drain (wind can blow the condensation back through the firewall since the missing elbow isn't directing it towards the ground)

and I'll add - 4. failed butyl seal on the evap section of the a/c box, not likely unless it's been disassembled in the past

Coincidentally, when I went to replace the heater core in the '93 dually, I found the cover was broken all to hell. I cleaned it really well and then patched it (hopefully) with some foil duct tape. Hack-y, but we're trying to keep it low budget here. You can still buy the cover new, for now..

That lower cover isn't designed to be a water tight seal, because it doesn't need to be. It's just sealing (most of) the airflow through the system as it passes over the heater core.




Richard

I've made a bunch of edits to that previous reply as my brain is waking up so if it looks like I left anything out, just refresh the page, LOL

Richard

that old grey caulk aka monkey dung