Possible Heater Core Leak

[hysteria357]

Hi All,

Back again for some assistance. I noticed about a week ago there were a few drops of red liquid on the passengers floormats. After searching the forums I fear it could be a heater core issue. I ran my inspection camera up there and saw what I hope isnt coolant. Apologize for the bad photos, I dont have an SD card for the camera so I had to take a picture of the screen. It looks to be multiple spots.

The weird thing is I just had significant work done to it in the past few weeks (PS rack, tie rods, LCAs, tons of windshield rust repair and re-sealing). I dont see any sort of commonality between these two parts, ruling out any sort of accidental damage. I get this is the nature of the beast owning 25 year old cars, but this seems really sudden.

Any advice on further tracking down the source of the leak? TIA

 

[hysteria357]

Had a thought... If i were to do the heater tee delete, wouldnt that mean the coolant would bypass the heater core? I live in a part of the country where it doesnt start getting "cold" till november/december-ish, so heat wont be necessary for the next 7 months. Would this be a temporary fix to, at a minimum, stop the leaks so I can push out that replacement without endangering the vehicle?

Any thoughts on this?

 

[Mike NXP]

Had a thought... If i were to do the heater tee delete, wouldnt that mean the coolant would bypass the heater core? I live in a part of the country where it doesnt start getting "cold" till november/december-ish, so heat wont be necessary for the next 7 months. Would this be a temporary fix to, at a minimum, stop the leaks so I can push out that replacement without endangering the vehicle?

Any thoughts on this?

If you eventually want to fix it right, I would probably just vote for monitoring coolant levels and topping off with proper coolant as necessary ( Toyota red for 98-02 / Toyota pink all for 02+ ) since it doesn't seem to be gushing out too bad .

 

[Ridgerunner78]

Can you smell coolant in the cabin, or do you have issues with the defrost fogging up the inside of the glass? I had those two issues long before I saw any coolant on my floorboard.

I'd make sure the AC condensate drain through the firewall isn't clogged. That can cause leakage onto the floor, but it usually isn't red.

It doesn't look like the camera is looking inside the heater box, more under it. To see a leak you'd have to be looking inside.

 

[SteveH]

Had a thought... If i were to do the heater tee delete, wouldnt that mean the coolant would bypass the heater core?

Yes - many folks just lock out the heater core(s) until summer comes or they have time to fix it. Ideally, you would cap off any open the system to prevent bugs and dirt from entering any part of the cooling system until you get it fixed and back online.

 

[hysteria357]

Can you smell coolant in the cabin, or do you have issues with the defrost fogging up the inside of the glass? I had those two issues long before I saw any coolant on my floorboard.

I'd make sure the AC condensate drain through the firewall isn't clogged. That can cause leakage onto the floor, but it usually isn't red.

It doesn't look like the camera is looking inside the heater box, more under it. To see a leak you'd have to be looking inside.

I remember when it was cold a few weeks ago I couldn't get the windows defogged no matter what I did. The heat still works, and works really well.

 

[hysteria357]

It doesn't look like the camera is looking inside the heater box, more under it. To see a leak you'd have to be looking inside.

wouldn't coolant on the outside of the box imply a leak from the inside? I attached a pic of what leaks down. This happened while I was at work.

 

[Ridgerunner78]

I remember when it was cold a few weeks ago I couldn't get the windows defogged no matter what I did. The heat still works, and works really well.

Yeah, exact same as mine.

wouldn't coolant on the outside of the box imply a leak from the inside? I attached a pic of what leaks down. This happened while I was at work.

Sure looks like coolant to me.

Completely bypassing the heater core would work until it gets cold again.

Replacing the heater core is a pain. Pretty sure they build these trucks around it. I have pics somewhere of when I did mine. The entire dash, and dash support bar have to come out. I went with a new OEM part from Toyota even though it was anywhere from 3x -10x more expensive than parts on RockAuto. If you have to go that far in, don't cheap out on parts.

 

[hysteria357]

Yeah, exact same as mine.



Sure looks like coolant to me.

Completely bypassing the heater core would work until it gets cold again.

Replacing the heater core is a pain. Pretty sure they build these trucks around it. I have pics somewhere of when I did mine. The entire dash, and dash support bar have to come out. I went with a new OEM part from Toyota even though it was anywhere from 3x -10x more expensive than parts on RockAuto. If you have to go that far in, don't cheap out on parts.

What really gets me is that it's dripping in 2 separate places which means it might be above? Maybe this weekend i'll pull the HVAC controls and head unit out and see if I can get my inspection camera further in there.

 

[hysteria357]

Also, the heater tee delete kit from cruiser patch wouldnt solve my issue, id have to make my own solution to bypass the heater core?

 

[leveeguy]

Also, the heater tee delete kit from cruiser patch wouldnt solve my issue, id have to make my own solution to bypass the heater core?

I’ve never done this but I’d think you could just bypass the front heater core (upper two connections) and keep the rear heater core (lower two connections) connected.

 

[hysteria357]

I’ve never done this but I’d think you could just bypass the front heater core (upper two connections) and keep the rear heater core (lower two connections) connected.

Guess i need to start doing some research on the cooling system

 

[FxFormat]

Evap core you can cheat by cutting the glovebox mount but heater core is buried in the dash. Toyota suspends the heater core in the air and built the truck around it. The leak doesn’t look too bad, I’ve had the same leak in my water pump for 2 years before I replaced my timing belt/wp. bypass it for now and worry about it in the fall, or start shopping for a Canada goose jacket lol

 

[hysteria357]

Evap core you can cheat by cutting the glovebox mount but heater core is buried in the dash. Toyota suspends the heater core in the air and built the truck around it. The leak doesn’t look too bad, I’ve had the same leak in my water pump for 2 years before I replaced my timing belt/wp. bypass it for now and worry about it in the fall, or start shopping for a Canada goose jacket lol

yeah ive only had to turn the actual "heat" on probably less than a dozen times last year. I can just drive my other car on the days where its covered in ice. I mostly want the leak stopped so it doesnt stain my carpet or cause other unintended damage. Is it legitimately as simple as cutting a high quality coolant hose to just... skip it?

 

[AARONTLC]

Long shot but, I would verify that you are not leaking at the tees and it seeping back through the wall (worn out grommet). If you lived near me I would say come over and let’s go for that heater core. I would love to document it for the forum. Good luck!

 

[DuckLN]

Have you replaced your radiator recently?

 

[hysteria357]

Long shot but, I would verify that you are not leaking at the tees and it seeping back through the wall (worn out grommet). If you lived near me I would say come over and let’s go for that heater core. I would love to document it for the forum. Good luck!

I'm gonna follow the hoses in depth this weekend. If I did have to replace it I'd be very concerned taking the dash out because it's starting to crack, and I'd be worried any sort of twisting motion will damage it further.

Have you replaced your radiator recently?

No. I think it's still the original.

 

[hysteria357]

update, I found the trail and where the coolant was pooling up. To the left of the evaporator, just above where the passengers feet would sit. Gonna try and follow it further but I still am going to bypass the heater core.

 

[Jack90210]

Also, the heater tee delete kit from cruiser patch wouldnt solve my issue, id have to make my own solution to bypass the heater core?

Correct, this mod only bypasses the rear heater core, not the front.

 

[hysteria357]

The leak has picked up and now the interior reeks of coolant. I'm gonna do a bypass this weekend, however I'd like to ask for feedback if it will cause any issues.
Option 1: disconnect the hose from the heater tees leading to the heater core and cap the open end of the tees. This would route all coolant through the rear heater. Easiest and most preferred.

Option 2: disconnect the heater core hoses from the tees and connect the two empty tee ends with a U shaped hose.

Option 3: run two lines together bypassing the heater tees and both heaters together.

I'd like to keep the rear heater so I have something, but would I run into any sort of throughput or pressure issues routing the all the coolant through the rear heater?