Might be a dumb question

Doggie Daddy

Veteran Expediter
As the title of the post states, this might be a dumb question but I ain't no mechanic so here goes.

Of the 3 sets of finned cooling devices in the front of the truck (radiator, charge air, a/c condensor) is the radiator the only one of the 3 that has coolant flowing through it?

I have a very small leak coming from this area, and just want to narrow down the possibilities of what it could be, as I can't actually see where it is coming from....thanks.

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paullud

Veteran Expediter
If you are leaking coolant from the front it will be the radiator or a hose near it. Sometimes a hose will start leaking and the coolant will run along the hose and drip off the radiator.

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ATeam

Senior Member
Retired Expediter
The AC has refrigerant and oil flowing through the system. An oil leak may appear from that. Engine coolant flows through the radiator. It has a distinctive taste. Are there any drips you might sample? (I'm serious). Be prepared to clean your tongue after sampling a drip. If you don't know what engine coolant tastes like, sample it fresh out of the bottle; one drop, clean tongue after.

Optional: Purchase from NAPA the Slick Lick Tongue Cleaner model 74-63D. (That part is a joke.)
 

zorry

Veteran Expediter
Any decent shop will be able to put a pressure tester on your radiator.
Essentially like a basketball pump with a pressure guage.
Attach in place of radiator cap and pump up to pressure. Just 3 or 4 lbs will push coolant out through the area leaking.
Driving a small leak can be blown around and sometimes hit something hot where it will evaporate.
If you're an O/O you may want to swing by Napa and buy one.
It should cost less than an hours labor in most shops and handy to have.
When I would pm my own trucks I would put pressure on system that simulated the pressure at operating temps and leave it on for the entire pm.
The main reason to do your pm is to inspect and find problems you can fix before a roadside breakdown.
If you buy one,be sure you get the adapter for your application.
 

zorry

Veteran Expediter
My 2004 Mack had a hose in front of the radiator.
It was not visible from standing next to the truck looking into engine compartment.
Kinda of wierd. I found it when it blew in Wyoming at 3am on a Sat morning.
 

Doggie Daddy

Veteran Expediter
Phil, not gonna taste it as I am 99. 44/100 % sure it is coolant. And thanks zorry.

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ATeam

Senior Member
Retired Expediter
Phil, not gonna taste it as I am 99. 44/100 % sure it is coolant.

I don't know, DD. You're leaving more than a one-half-of-one-percent chance that you might be wrong. A real truck driver would do the taste test.
 

Rocketman

Veteran Expediter
To your original question:

A/C condenser will have refrigerant in it. (If you were loosing very much here, your a/c system would be needing charged)

The charge air cooler is filled with air (side note: a leaking charge cooler is an invisible mpg loss)

The radiator (and anything connected to it) will have engine coolant in it.

So yes, the radiator and connected components are probably where you need to look.
 
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Rocketman

Veteran Expediter
The AC has refrigerant and oil flowing through the system. An oil leak may appear from that. Engine coolant flows through the radiator. It has a distinctive taste. Are there any drips you might sample? (I'm serious). Be prepared to clean your tongue after sampling a drip. If you don't know what engine coolant tastes like, sample it fresh out of the bottle; one drop, clean tongue after.

Optional: Purchase from NAPA the Slick Lick Tongue Cleaner model 74-63D. (That part is a joke.)
Just to be sure everyone knows this. The old type antifreeze (the green stuff) is toxic and can kill small animals. Im guessing humans too. What Phil suggests here is fine I'm sure, I've seen people do it and they didn't fall over dead. Just remember though, Phil said "a drop"...as in a single drop...a very, very small amount.

Coolant licker :D
 

BobWolf

Veteran Expediter
Owner/Operator
Don't worry abbout the taste test it wont hurt you in fact you will consume more propyline glycol and or ethelyne glycoll from processed foods, artificial sweetners, and especilay margrine. .
Now, if you drink a quart or two thats a different storry then you have problems. So, dont make a margarita out of it. Just remember to spit and or rinse with a mouthfull of water afterwards.

Exetnded life red coolant will usualy leave jell trails. White run marks where leaking. Freon will be oily and usualy clear or light tint, Trasn fluid if healthy will be red to slight yellow if it has a few miles on it, and will be oily.
Bob Wolf
 

Doggie Daddy

Veteran Expediter
Still ain't gonna taste it, just gonna go out on a limb and say that it most definitely is coolant.

This is very small leak, and only appears on the ground when the engine is not running. If the truck is idling (rare) the is no sign if it, could be the fan is redirecting it.

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zorry

Veteran Expediter
Leaks seldom heal. When you start getting cooler nights the metal will contract more than the rubber hoses. You get "cold leaks" which will disappear when you bring engine up to temp.
 

ATeam

Senior Member
Retired Expediter
This is very small leak, and only appears on the ground when the engine is not running. If the truck is idling (rare) the is no sign if it, could be the fan is redirecting it.

When you notice the coolant on the ground, is the engine hot, cool or does it leak at any temp?
 

Rocketman

Veteran Expediter
Still ain't gonna taste it, just gonna go out on a limb and say that it most definitely is coolant.

This is very small leak, and only appears on the ground when the engine is not running. If the truck is idling (rare) the is no sign if it, could be the fan is redirecting it.

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Likely what they call a cold water leak. When at operating temps, heat expansion seals the leak. When parked, as everything cools back down, the leak reopens. I had the same problem with my ST. On inspection, I could see a trail of water coming from the center of the radiator when truck was parked and engine cool. Hose clamps can and do cause the same exact problem, so a good inspection is in order to be sure your repairing the right part.

Of course, my truck was older and with some miles on it...so, I dropped a bottle of leak sealer in it (cant remember what I used exactly). I never had another problem with mine.

If its the radiator, the proper repair would be removal at a good radiator shop where they would seal the leak, flush, clean and pressure test it.
 
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Rocketman

Veteran Expediter
After thinking about this a bit. Try the quick and easy first. When the engine is cool, preferably early in the morning when it is the coolest, tighten every hose clamp. Good chance your leak will go away.
 

Moot

Veteran Expediter
Owner/Operator
I'm with Rocketman, tighten all hose clamps. If you aren't using constant-torque hose clamps, this might be a good time to replace your old clamps with these.
 

Doggie Daddy

Veteran Expediter
Thanks for the suggestions guys, I am just hoping it doesn't turn out to be the radiator. ( $760.00 ) :eek:

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