Coolant dropping in Reservoir (1 Viewer)

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Need a plan of attack! 87 fj60 smogged 2F. the Coolant in the reservoir is dropping after a couple of days I have to add some to keep it at Half way on the reservoir when the motor is cold. New water pump, all new hoses, new tstat, I do not over heat or even come close. the temp gauge sits right in the middle. there is her evidence of coolant on the ground. No white smoke. I random light smell of coolant when I replaced everything. that has been about 6 months ago. did a chemical head gasket test, no head gasket leak. the only thing I can think of is a Core leak in the radiator so small if it leaks its getting burned off before it can drip. Did a pressure test no obvious leaks and no leak down. BUT THE COOLANT HAS TO BE GOIGN SOME WHERE!!!
 

Cincodemustache

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If you just replaced all of those items in the cooling system you may still have some air circulating. When the truck cools it could be purging that air and sucking in coolant for the reservoir to replace.

Maybe some smarter folks could chime in, so at the least I’ve bumped your issue back to the top of the forum
 

mattressking

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Run the heat and turn rear heater on as well. let it cycle and run then let it cool and top off as-needed. You might not have eliminated all the bubbles which is my assumption.

Inspect all lines under truck for leaks also. If no visible leaks anywhere, do a compression check and see if a cylinder or two is lower than 15% of the highest cylinder as last resort.
 

2mbb

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Since you pressure tested the cooling system and didn't find any pressure drop, then I'm going to suggest it's something you didn't test: the radiator cap, or the expansion tank system. Replace the cap, make sure the expansion tank isn't cracked, the tubing doesn't have a hole or split and the tubes to the cap are installed correctly.
 
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The cap is brand new Toyota when I did all the other work. Also the reservoir is new. And all hoses from radiator to the over flow tank.
 
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I brought it up to temp and Leto g it cool now. But I did notice a pretty steady drip coming just below the top hose. This has never been here before. I did lose a little coolant from the pressure test. So I’m seeing if it’s just run off or an actual leak. Wondering how I figure out if it’s the hose or the actual radiator
 
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Now I’m just worried about that leak now!! Or drip I should say. I’m trying so hard not to replace the radiator.
 

2mbb

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go back to the pressure test. maybe use a fluorescent light or even just a flashlight, inspection mirror, your hands, etc. with the engine cold. You should be able to tell where it is coming from especially since you now know where to look for it.
 
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Ended up ordering a new radiator 🤬. Pretty good drip when it get up to pressure. It would drip inside the fan shroud so it would never hit the ground. Then it would dry there. Never saw it
 
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Run the heat and turn rear heater on as well. let it cycle and run then let it cool and top off as-needed. You might not have eliminated all the bubbles which is my assumption.

Inspect all lines under truck for leaks also. If no visible leaks anywhere, do a compression check and see if a cylinder or two is lower than 15% of the highest cylinder as last resort.
Can I ask, what would the compression test help me with the cooling system. It’s funny you say that. I got a compression tester. But I didn’t really think they were connected
 

Gretsch

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Can I ask, what would the compression test help me with the cooling system.

Same idea as your chemical head gasket test, just different way to do it. Low compression in a cylinder could indicate a leak in the head gasket, a crack in the head itself, or a cracked block as the cylinder is for some reason no longer sealed enough to allow the cylinder to develop compression. Not to speak for him but @matressking was just providing another method to check for a leak, perhaps giving you a reason for having the coolant burn away like it is. If there was a crack somewhere allowing coolant to internally enter the cylinder you wouldn't see that. Since you found the leaks you can see, this might help find the ones you can't. Several tests can be done to find the reason coolant is disappearing. Sounds like you found your leak already though. HTH.
 
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Same idea as your chemical head gasket test, just different way to do it. Low compression in a cylinder could indicate a leak in the head gasket, a crack in the head itself, or a cracked block as the cylinder is for some reason no longer sealed enough to allow the cylinder to develop compression. Not to speak for him but @matressking was just providing another method to check for a leak, perhaps giving you a reason for having the coolant burn away like it is. If there was a crack somewhere allowing coolant to internally enter the cylinder you wouldn't see that. Since you found the leaks you can see, this might help find the ones you can't. Several tests can be done to find the reason coolant is disappeaSounds like you found your leak already though. HTH.
Well I believe the radiator is leaking. But at idle sometimes I get a little darkish smoke. So I was thinking my rings might be not performing like they should. So that’s why I bought the tester. After installing the new radiator. I will do the compression test to to see the results. Dry and wet to see what the numbers are.
What is spec for compression?140-150?
 

Seth S

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Well I believe the radiator is leaking. But at idle sometimes I get a little darkish smoke. So I was thinking my rings might be not performing like they should. So that’s why I bought the tester. After installing the new radiator. I will do the compression test to to see the results. Dry and wet to see what the numbers are.
What is spec for compression?140-150?

Black smoke = too rich
Blue smoke = oil burning from somewhere
White Smoke = Coolant burning or a new pope has been elected
 
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Black smoke = too rich
Blue smoke = oil burning from somewhere
White Smoke = Coolant burning or a new pope has been elected
Is there a way to test if “to rich”? Or you just hope the mixture is correct from the lean drop? I guess look at your plugs too.
What color is Normal exhaust ? Light white?
 

Seth S

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Is there a way to test if “to rich”? Or you just hope the mixture is correct from the lean drop? I guess look at your plugs too.
What color is Normal exhaust ? Light white?
Normal exhaust should be pretty much invisible once the truck has warmed up. The color you see in the cold exhaust is usually just a mixture of condensation in the exhaust and the normal water that is produced as a byproduct of the combustion process. There are 2 ways to determine your fuel mixture: 1) Invest in a wide band O2 sensor and install a gage in the cabin or hook it up to a lap top to data log during different driving conditions and adjust the carb from there, 2) have someone put the emission sniffer up the tail pipe (of the truck).

Otherwise the old school technique is to look at the plugs...lean drop method....and not sure what other tricks for a simple carbed engine there are
 

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