Coolant Loss/Broken Radiator Piece (2 Viewers)

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

Joined
Apr 26, 2025
Threads
3
Messages
15
Location
So Cal
I took the cruiser on about a 550-600 mile trip this weekend. This morning when I checked, my coolant reservoir was almost completely empty. I opened the radiator cap and it had coolant up to the top. Temperatures during driving were right at the halfway mark and never had a dash light for low coolant. Car currently has 221k miles and timing belt/water pump were done at 188k. I have been looking at some of the coolant leak threads and tried to check common spots and haven't found a leak. What I did find is this piece on the radiator was broken. Is this just a mounting piece or can coolant actually evaporate from this hole? First picture is the driver side and second is the passenger side which is not broken. It looks like the piece itself is part of the entire radiator so doesn't seem I could just replace it. If this is not the cause of the coolant loss, I guess I can do the coolant flush I was planning on doing and continue to monitor.

IMG_9687.JPG


IMG_9688.jpeg
 
Mounting tabs. If you were losing coolant there you'd see coolant there and/or pink coolant residue.
Got it, thanks. I looked around and couldn't find where the coolant was leaking. I was already planning a coolant flush so I'll do that and monitor.
 
Check your heater T’s. Also, coolant will expand when hot/warm. Significantly. I have been studying this in my GX. If the top of the rad is sort of brownish yellow it’s probably going to start leaking soonish in my experience. Both of my hundos needed a new rad between 230-250k. Just did the 250k one this weekend.
 
Check under oil fill cap for any milky stuff.
Checked oil cap and no milky stuff. I removed the skid plate and checked under and couldn’t find anything that looked like leaking coolant. The radiator cap looks pretty old so i’m wondering if maybe that’s the problem. Saw that as a possible issue when reading through the forums. It’s also very possible I missed something when checking as I’m not very experienced checking for stuff like that.
 
Check your heater T’s. Also, coolant will expand when hot/warm. Significantly. I have been studying this in my GX. If the top of the rad is sort of brownish yellow it’s probably going to start leaking soonish in my experience. Both of my hundos needed a new rad between 230-250k. Just did the 250k one this weekend.
It didn’t look like it was leaking from the heater T’s. But I’ll have to double check but I do recall the color not being red but more orangish in the radiator so I may just be needing a new one soon.
 
It didn’t look like it was leaking from the heater T’s. But I’ll have to double check but I do recall the color not being red but more orangish in the radiator so I may just be needing a new one soon.
Check the actual color of the top cap (the whole top length). The top cap is plastic, as it goes through its thousands and thousands of heat cycles it will change color as it weakens.
If you look in the pic, compare the color of the fan shroud attachment points to the top cap. The new one by comparison is very dark. Look down between the top cap and you will see little metal “dashes” look for coolant here or evidence the top hose has been weeping
IMG_0460.jpeg
IMG_0474.jpeg
IMG_0409.jpeg
.
 
Those were helpful. I wiped the dust off from the top of the radiator and it does look pretty brown, but didn't notice and leaks from the top portion. Regardless, probably should change it. I did notice the top hose had some white residue which may be where it is weeping from. I circled it in red in the picture, is this it or is this not enough for almost the entire reservoir to have leaked from. Also the part of the top hose that connects to the radiator is pictured. I also have pictures of the heater T's which to me looked to be more dust, but let me know if that actually looks more like coolant. I plan to change the heater T's anyway, but would be good to know if that's where the leak is.
IMG_9702.jpeg
IMG_9701(1).jpeg
IMG_9699.JPG
IMG_9698.jpeg

IMG_9697.jpeg

Check the actual color of the top cap (the whole top length). The top cap is plastic, as it goes through its thousands and thousands of heat cycles it will change color as it weakens.
If you look in the pic, compare the color of the fan shroud attachment points to the top cap. The new one by comparison is very dark. Look down between the top cap and you will see little metal “dashes” look for coolant here or evidence the top hose has been weepingView attachment 3915640View attachment 3915641View attachment 3915645.
 
Those were helpful. I wiped the dust off from the top of the radiator and it does look pretty brown, but didn't notice and leaks from the top portion. Regardless, probably should change it. I did notice the top hose had some white residue which may be where it is weeping from. I circled it in red in the picture, is this it or is this not enough for almost the entire reservoir to have leaked from. Also the part of the top hose that connects to the radiator is pictured. I also have pictures of the heater T's which to me looked to be more dust, but let me know if that actually looks more like coolant. I plan to change the heater T's anyway, but would be good to know if that's where the leak is. View attachment 3916941View attachment 3916942View attachment 3916938View attachment 3916939
View attachment 3916937
Heater T’s look like they may be original. Usually a sign when they are still in the factory (pain to get to) position.

Top hose (hose number 1) looks like the constant friction clamp has been moved. I would move it back to its original position. Sort of hard to tell but there may be some weep there.

I would add coolant to the overflow in the early morning up to the full line. Note the ambient temp, or if you are industrious shoot the tank with a temp gun. Keep track over a couple of weeks and see if you are losing coolant, but do note that hot coolant will take up more space.

IMG_0254.jpeg
IMG_0255.jpeg
IMG_0257.jpeg
IMG_0258.jpeg
 
Heater T’s look like they may be original. Usually a sign when they are still in the factory (pain to get to) position.

Top hose (hose number 1) looks like the constant friction clamp has been moved. I would move it back to its original position. Sort of hard to tell but there may be some weep there.

I would add coolant to the overflow in the early morning up to the full line. Note the ambient temp, or if you are industrious shoot the tank with a temp gun. Keep track over a couple of weeks and see if you are losing coolant, but do note that hot coolant will take up more space.

View attachment 3916979View attachment 3916980View attachment 3916981View attachment 3916982
Thanks, I’ll move the hose back. Would it be fine to add distilled water and monitor? I’m not sure what coolant was used prior to buying the car and don’t want to mix them. I know it was red coolant but just want to be sure.
 
What year is your 100? There are two variants. “Red” or long life, and “Pink” or super long life. There is a whole thread on these and what year they changed over. If it’s Red you will dilute because it comes concentrated. Pink is already 50/50. I believe (but please refer to the thread) that pink can be added to red. I think there is a TSB for that.
 
What year is your 100? There are two variants. “Red” or long life, and “Pink” or super long life. There is a whole thread on these and what year they changed over. If it’s Red you will dilute because it comes concentrated. Pink is already 50/50. I believe (but please refer to the thread) that pink can be added to red. I think there is a TSB for that.
Mines an 03 and I’m pretty sure it was red previously used in my car. Based on what I read on the forums pink will work but red is the preferred option. I have a gallon of red which I would beed to dilute. I was thinking of using just diluted water to test loss so I’m not wasting coolant since I was planning to flush anyway.
 
Mines an 03 and I’m pretty sure it was red previously used in my car. Based on what I read on the forums pink will work but red is the preferred option. I have a gallon of red which I would beed to dilute. I was thinking of using just diluted water to test loss so I’m not wasting coolant since I was planning to flush anyway.
When mine was leaking, and it was really going, I did put enough distilled in there to fill up the rad and move it from the driveway to the garage once I got the parts. I was performing a full system drain and refil. My fluid looked good and the rad looked terrific inside (it has had very regular flush's). I know folks will flush with distilled and obvously it is used to mix with the concentrate. The ratio will of course change your freeze protection and boil-over threashold, but if you are going to flush anyway it seems reasonable to me. There is some evidence that some of the distilled used to flush remains within the cooling loop so take that into consideration. The overflow tank doesn't hold that much, so maybe just mix it properly? When you do the flush or drain and fill get one of those Lisle 24680 funnel fill kits, I'd like to shake whom-evers hand that came up with that! A flex head ratcheting end wrench (10mm) for the passenger side block drain will help. As will some 5/16 ID tubing. That passenger side block drain is right smack behind and above two lines and a bracket, you will be going by feel.
 
When mine was leaking, and it was really going, I did put enough distilled in there to fill up the rad and move it from the driveway to the garage once I got the parts. I was performing a full system drain and refil. My fluid looked good and the rad looked terrific inside (it has had very regular flush's). I know folks will flush with distilled and obvously it is used to mix with the concentrate. The ratio will of course change your freeze protection and boil-over threashold, but if you are going to flush anyway it seems reasonable to me. There is some evidence that some of the distilled used to flush remains within the cooling loop so take that into consideration. The overflow tank doesn't hold that much, so maybe just mix it properly? When you do the flush or drain and fill get one of those Lisle 24680 funnel fill kits, I'd like to shake whom-evers hand that came up with that! A flex head ratcheting end wrench (10mm) for the passenger side block drain will help. As will some 5/16 ID tubing. That passenger side block drain is right smack behind and above two lines and a bracket, you will be going by feel.
Thanks for all the help, really appreciate it. I’ll add some to the reservoir and see what happens. I’ll clean the residue from the top hose and move the clamp too and see if I’m losing coolant.
 

Users who are viewing this thread

Back
Top Bottom