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Noticed a pair of these drain nipples underneath the car today, one driver’s side and one passenger’s side.
When the car gets up to temp it leaks/drains a fair amount of coolant from each nipple. I recently flushed and refilled the coolant so wondering if that has anything to do with it.
Here’s a video: https://youtu.be/88RagCOdt9M
Normal or something I need to fix? What is this a sign of?
That there's a lot of moisture in the air. The a/C operates all the time the hvac is on to dehumidify the air. You only need to worry if there is antifreeze coming out(bad heater core). Just water, no worries.
That there's a lot of moisture in the air. The a/C operates all the time the hvac is on to dehumidify the air. You only need to worry if there is antifreeze coming out(bad heater core). Just water, no worries.
Unfortunately there’s antifreeze coming out, so sounds like I have a problem. Here’s what’s weird though: this is a Chevy 350 lump, and the heater core hose has a manual valve you can open and close in the engine bay. I have it closed right now so wondering why it’s doing this.
I also disconnected the AC compressor completely since it wasn’t working anyways (and again being an old swap car with some odd electronic issues, I figured it safer to keep the AC totally off until I get a chance to take a closer look at that system).
Is shutting off the heater hose valve and disconnecting power from the compressor part of my problem?
No. The valve probably only shuts off the inlet side. The outlet side is still connected to the cooling system and is under pressure, so a leak in the heater core would still leak antifreeze. If you car is an 86 or earlier, the dash is supposed to come out to replace the core. 87 and later with the Delanair 3 system, the core can be replaced without removing the dash. Some people cut the pipes to the heater core on the earlier system so they can replace the core without pulling the dash, but you have to spice the pipes on the new core with heater hose to do that.
No. The valve probably only shuts off the inlet side. The outlet side is still connected to the cooling system and is under pressure, so a leak in the heater core would still leak antifreeze. If you car is an 86 or earlier, the dash is supposed to come out to replace the core. 87 and later with the Delanair 3 system, the core can be replaced without removing the dash. Some people cut the pipes to the heater core on the earlier system so they can replace the core without pulling the dash, but you have to spice the pipes on the new core with heater hose to do that.
Unfortunately it’s an 83. Thanks, time to dive in!
No. The valve probably only shuts off the inlet side. The outlet side is still connected to the cooling system and is under pressure, so a leak in the heater core would still leak antifreeze. If you car is an 86 or earlier, the dash is supposed to come out to replace the core. 87 and later with the Delanair 3 system, the core can be replaced without removing the dash. Some people cut the pipes to the heater core on the earlier system so they can replace the core without pulling the dash, but you have to spice the pipes on the new core with heater hose to do that.
Hey Jal, before I go through the hassle of replacing the heater core, is there anything else that this could be? And just for my own education, by what mechanism is coolant draining due to a bad heater core? I assume it’s not just a leak or it would be dripping inside the car, which I’ve not seen any evidence of. Just trying to understand exactly what is happening inside/around the core that’s led to this problem.
The coolant is going thru the drain tubes rather than into the cabin, just as the a/c condensate does. If the leak was worse, or the tubes clogged, it might be a different story.
However......
With a leaky heater core you'd typically get the sweet-ish smell of coolant in the cabin. And/or steamed-up windows. OTOH, not every failure is typical
At the end of the day, though, if you're getting coolant thru the a/c drain tubes I don't see how it could anything except a heater core.
Those drains you found are for the condensate from the a/c evaporator. The heater core is contained in the same housing as the evaporator. The heatet core is leaking, and antifreeze is coming out of the condensate drains.
Those drains you found are for the condensate from the a/c evaporator. The heater core is contained in the same housing as the evaporator. The heatet core is leaking, and antifreeze is coming out of the condensate drains.
Have the system pressure tested.
If the leaking shows up from those points you need to address the heater core.
Could be just a loose connector or rotted core.
Good luck.
The coolant is going thru the drain tubes rather than into the cabin, just as the a/c condensate does. If the leak was worse, or the tubes clogged, it might be a different story.
However......
With a leaky heater core you'd typically get the sweet-ish smell of coolant in the cabin. And/or steamed-up windows. OTOH, not every failure is typical
At the end of the day, though, if you're getting coolant thru the a/c drain tubes I don't see how it could anything except a heater core.
Cheers
DD
I have the steering column removed and the heater core drained. Before I go any further I need clarification regarding Kirby Palm and Michael Neal’s method of cutting the heater core pipes to remove the core without having to take the entire center console apart. Do I pull the heater core out of the driver side or passenger side footwell? Here’s a video with exactly what I’m talking about:
If you are totally bent on doing more work than you have to, go ahead and remove the core.
For my money, I would pressurize the system to see if you get more dripping from those drains.
If you are totally bent on doing more work than you have to, go ahead and remove the core.
For my money, I would pressurize the system to see if you get more dripping from those drains.
This is the kit I have to pressurize the cooling system. I suspected a heater core leak and when I pressurized my system it would drip out the AC condensation drains.
For reference, here is what my heater core looked like after I removed it.
I might actually have you beat on this one:
Photo doesn’t do it justice. Looked like it came off the Titanic. New one comes in Friday. I’ll pressure test it tomorrow just for fun, but I think I know how that’s going to go.
Photo doesn’t do it justice. Looked like it came off the Titanic. New one comes in Friday. I’ll pressure test it tomorrow just for fun, but I think I know how that’s going to go.
@MrAndersonGCC and @Thorsen I'm sure you're both pretty exhausted,,, but how did you get it (them) out?
@JayJagJay I went the unconventional route of completely removing the Delenair MkIII box and controls, but with small enough hands you can remove the heater core relatively easy on the cars with the Delenair MkIII system.
01-01-2022, 02:23 PM
Coolant drain nipple?
