Coolant leak when cold (2 Viewers)

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Today when I start up the 80, I let it run for a little bit since it was cold. About 30 degrees. I came out about 10 mins later and there was a small puddle of coolant (or at least I assume it is coolant) under the car. It is brownish red. It was on the driver's side, kind of under the battery.

I checked the fluids and everything looked normal. I remembered last winter I also had a similar issue when intermittently coolant would leak about with no clear leak. It would intermittently do this and then all of a sudden stop. I drove and wheel the truck this summer and hadnt noticed any leaking. The temps seemed normal around 186-190. The only think of note is the heat that truck throws out is amazing.

Is it possible it is a transmission or power steering leak? I checked the power steering fluid and it also at a normal level.
 
Today when I start up the 80, I let it run for a little bit since it was cold. About 30 degrees. I came out about 10 mins later and there was a small puddle of coolant (or at least I assume it is coolant) under the car. It is brownish red. It was on the driver's side, kind of under the battery.

I checked the fluids and everything looked normal. I remembered last winter I also had a similar issue when intermittently coolant would leak about with no clear leak. It would intermittently do this and then all of a sudden stop. I drove and wheel the truck this summer and hadnt noticed any leaking. The temps seemed normal around 186-190. The only think of note is the heat that truck throws out is amazing.

Is it possible it is a transmission or power steering leak? I checked the power steering fluid and it also at a normal level.
The exact thing just happened to me this morning. Leak was gone after warm-up. 29 degrees here.
 
last night I noticed my kids truck had a basically zero fluid in it. It was overheating in 40 degree weather. I want to do a full replacement of the water pump, radiator and water hoses. I did notice around the t-stat that there are a ton of gaskets etc. I called a local import shop and they said they do not have parts for this. Do you all have an online retailer that is knowledgeble on this stuff? I do not really want to get all of his apart and then have to wait on parts. I am hoping there is a retailer that truly knows these trucks and not a parts geek type place.
 
Look directly above (from below and above) where the fluid is dripping and try to locate the leak. In the area "roughly" under the battery, being brownish red, it could technically be any of those fluids (and its color could indicate old coolant with rust or old dirty ATF from power steering or transmission). It shouldn't be hard to tell whether it's watery or oily. If you can't find the source visually, monitor each of those fluid levels daily under the same conditions (like always in the morning when cold, or whatever) until you figure it out.

@RMabus if you search, you'll find every part number and other info you need - it's all well covered here. Use google, not the forum - like "water pump part number ih8mud 80" for example. It will also depend which year your truck is as hoses/radiator/etc differ between the two engines. Use OEM for thermostat/gaskets, hoses, water pump etc, but there are a few decent radiator options. Cheap aftermarket stuff will have you back in there replacing it again eventually, so better to do it once & do it right. If you're doing a cooling system overhaul, best to do every part down to an OEM radiator cap, and all that stuff can be found in a variety of established threads.
 
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This is my sons truck and I really want to deal with reliability. I want to replace it all in more of a restoration spirit, rather than wait for a weaker link to fail. I googled water pump and thermostat housing gaskets and parts and got one gasket, not the o rings or heater gaskets. Thats why I really wanted to find a parts house that I can call and walk through all of it. I am actually more of a rover guy and Rovers North is sort of what I am hoping to duplicate here.
 
I was a Rover guy too. Sold my 110 last year. I havent found an RN style set up. Wits End has a lot to offer, I have been using parts.toyota.com to get part numbers and diagrams and then search the web there.
 
@burlsube : What model/year 80 series are you working on? What color is the coolant in the radiator? (red, green?).

Can you stick your finger in the fluid that leaked and smell it? Coolant/Anti-freeze has a sweet smell, very different than transmission fluid.

The radiator (FJ or FZJ80) has a drain plug (petcock) on the left bottom side, IME they almost never leak unless it was recently fiddled with. The radiator itself could be leaking so you want to find where the leak is coming from in the event there is a crack somewhere about to get larger. Or it could be the radiator hose on that side that's leaking.

There are also transmission cooler lines located near the left side of the radiator, could be a leaking hose or even a rusted out metal pipe (in the FZJ80 transmission cooler circuit) that's developed a pinhole leak.
 
This is my sons truck and I really want to deal with reliability. I want to replace it all in more of a restoration spirit, rather than wait for a weaker link to fail. I googled water pump and thermostat housing gaskets and parts and got one gasket, not the o rings or heater gaskets. Thats why I really wanted to find a parts house that I can call and walk through all of it. I am actually more of a rover guy and Rovers North is sort of what I am hoping to duplicate here.
Go here https://partsouq.com/ and search parts by your vehicle. You can get full schematics with the correct part #'s.

Buy the parts from partsouq or use the #'s to buy them at other places.
 
Go here https://partsouq.com/ and search parts by your vehicle. You can get full schematics with the correct part #'s.

Buy the parts from partsouq or use the #'s to buy them at other places.
X2 for Partsouq. It’s fairly helpful once you learn the way they organize. Use your VIN or you may be lost in the vast iterations of Toyota vehicles for the global market. Lots of threads here for parts sources, but know that some have gone away.

@Kernal has good advice. If you’re serious about chasing leaks you should do some cleaning. It gets pretty difficult to spot leaks when there is 1/2” of caked on greasy dirt.

Also maybe time to think about how old the cooling system components are. Is it time for new hoses?
 
The headgasket was done by the PO like 4k ago so most look good. I'm still trying to figure out the origin, but ill start by just tightening some hose clamps and go from there.
 
Burlsube. I watched a video from a guy today and it became abundantly clear that there are many areas for leaks by the water pump, and t-stat housing. Thats why I hijacked your thread(sorry) but my guess is a metal part is cold, heats up and covers gaps cavities. Wonder if it would help you to have someone start your truck while cold and let you have your head under the hood?
 
@burlsube : What model/year 80 series are you working on? What color is the coolant in the radiator? (red, green?).

Can you stick your finger in the fluid that leaked and smell it? Coolant/Anti-freeze has a sweet smell, very different than transmission fluid.

The radiator (FJ or FZJ80) has a drain plug (petcock) on the left bottom side, IME they almost never leak unless it was recently fiddled with. The radiator itself could be leaking so you want to find where the leak is coming from in the event there is a crack somewhere about to get larger. Or it could be the radiator hose on that side that's leaking.

There are also transmission cooler lines located near the left side of the radiator, could be a leaking hose or even a rusted out metal pipe (in the FZJ80 transmission cooler circuit) that's developed a pinhole leak.
It is a 96. So technically a FZJ80. The coolant in my radiator is reddish more like rust to be honest. I think some one mixed red and green. I'd say I'm due for a flush.
 
@burlsube

You need to get your hands a coolant system pressure tester. Pressurize your system and find that leak.

 
you can build a pressure tester quite easily.

cut a schader valve off an old bike tube, unplug overflow hose from the overflow bottle cap and insert the schrader valve into it. Secure with a clamp over it and also where the hose connects to the radiator. use a bike pump with gauge (preferably a MTB shock pump with gauge) and slowly pump up till you reach about 15psi. any external leak will be found. Do not over pressureise

i used this method to track down a miniscule crack in the radiator years ago that was a real pain to locate :)
 
Had the same issue 2 mornings ago. Went out before work early in the morning and started the cruiser up and went back in the house. A couple of minutes later I came out to find a little puddle of what looked like water under the front of the truck. I got down on the ground and took a little taste test and sure enough it was coolant. I was pretty familiar with the cooling system having replaced all of it over the past few months so I had a pretty good idea what it could be. Investigation from the bottom up found the top large coolant hose clamp had a tiny drip under it resting on the top of the radiator . Put a little righty tighty on the clamp and all good. Seems like the first cold snap always finds the weakest link in the system and exposes it.
 
I'm tracking down a cold weather coolant leak too. It leaked not a drop of anything all summer or during the prior three weeks while touring in Mexico. Now that I'm home, it leaks a bit of coolant each night with temperatures dropping into the single digits or teens.
 
1. How cold is cold?
2. How flexible are your hoses?
3. How old are the hoses?
4. What type of clamps are you using? (ie standard clamps from the hardware store or Toyota or other "variable pressure" clamps.

I know these may be sort of mice level questions, but they may help the community see a pattern.
 
I agree with the idea of the clamp type perhaps being an issue, I used cheaper screw type clamps on the large radiator hoses instead of a variable type. I do think this is the issue. They seem to work fine until a season change, kinda like an old 12v battery.
 

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