Coolant leak - radiator?

I've got a coolant leak that I can't positively identify the source of. I mistakenly thought it was the upper radiator hose at both ends. I was finding coolant puddled up below the hose on the upper timing chain cover, as well as splashed around the upper hose at the radiator.

I changed the hose and in the process cleaned up both connections very well, but I've still got evidence of a leak. Now, I think maybe the radiator is leaking near the top. Somehow, that is getting on the hose and running along the bottom over to the engine. Along the way some drips and is getting sprayed by the fan and belts? I'm guessing. Do you see anything in these pictures?

Thanks

 

Look for a hairline crack in the upper plastic on the radiator. Mine was cracked there last year. Can't say for sure that's it but others seem to have had the same issue.

I've noticed leaks like this can be found fairly easy during a cold start. Pop the hood first, dry everything off, start it and see what drips.

 

Go to your local parts house and borrow a system pressure tester. You'll easily pinpoint the problem area rather than guessing.

 

When you use that type of hose clamp on plastic parts, such as the radiator, it's easy to overtighten them and crack the plastic... I'd bet that's you're problem.

 

Since you already changed the hose, what's the condition of the radiator cap? An old weakened cap will spew fluid, but usually it goes all over the place when it spews. Another place is a possible crack in the overflow tank or the hose that goes from the radiator opening to the overflow tank may have weakened.

Looking at the 2nd photo, in the lower right corner, is that dryed red coolant? The reason I ask is, the tanks are plastic and they have a rubber seal between them and the radiator. Those little tabs on the radiator are bent over to fasten the tank to the core. Perhaps that rubber seal has failed and is allowing the coolant to leak. I don't know how that explains the coolant puddleing under the hose and onto the fan shroud. Your correct that the coolant is finding its way to the fan and blowing back onto the timing belt cover.

A way to troubleshoot an upper tank leak is to drain out just enough coolant to lower the level so that the upper tank is empty, but maintaing a safe level of coolant. Start the truck and see if the leak returns. You will still have enough coolant in the radiator to cool the engine so there's no fear of overheating. If the leak returns, you've located the source. If not, then the leak is either in the core or somewhere else. Good luck, I hope this gives you some assistance. Let us all know what you find out.

 

as mentioned get a radiator system pressure tester, they can be rented at most auto stores for a couple of dollars. then pressurize the system and it should be easy to find the leak while the engine isn't running to splash it all over the place.

a trick to source the area of a leak that could be on either end of a hose is to put a slider on the hose so water cant run along it and it has to drip off. take a paper plate and cut an X shape in the middle of it about the size of the hose but a little smaller then fold the tabs back and slide it over the hose and duct tape it in place using the folded over tabs to hold it in place.

place it so its not touching anything and any water that wants to run along the hose will stop there and be forced to drip from there. this will confirm its the radiator end but i think we can all agree we are certain that's it anyway but the explanation above will help you trace and leak that you aren't sure which end is leaking.

 

Great idea. I didn't know those existed, but it makes perfect sense. I'll see if I can get one from the Autozone across the street.

What type of hose clamps are correct for that fitting?

 

I think the factory uses a spring type clamp but that clamp you have is fine to use as long as you dont overtighten it, that's the problem.

once the hose is tight so it wont turn then just tighten a little more and check for leaks after it gets hot. you don't want to turn the screw until its tight, you just want to tighten it so it doesn't leak. most likely that's no more then finger tight not palm grip tight.

 

Radiator leaks are what TP-3900 was designed for.

http://www.tracerline.com/tags/tp-3900

http://www.summitracing.com/parts/trl-tp-3900-0601

Ed

 

I caught it. The cold-start-and-watch did it. It's coming from the upper hose connection on the radiator.

I'm going to let it cool off, then take the hose off and see if I can find a crack. I'll report back.

Thanks for the help.

 

if its the plastic neck that is cracked you can probably fix it by wrapping it in fiberglass.

just an option to keep in mind

 

If there's a crack I can't find it. I put it back together, topped it off, and ran it for about 15 minutes. It didn't leak.

3 possibilities.

1. I put the host clamp on tighter this time than it was before.
2. This wasn't exactly a cold start and it needs to be to find it.
3. The damn thing simply won't leak in the driveway (when I caught it was in the parking lot at work)

 

Glad to hear that you may have it sorted out.

 

If that's it, you got away easy. Your Radiator cap in good shape?. A radiator rebuild shop usually has the better pressure test tools,,and most will gladly check your cap for the right relief psi. Better to vent thru the cap into the catch can, than where it is leaking? now.

If it leaked only in the work lot,,, it heated up after engine shutdown and then tried to belch off the pressure after engine shutdown,,but it found a loose clamp, or a hairline neck crack that wont open until things are warm and loose.

You want to run that hose and clamp right up to the base of the neck on the radiator,,because the material is molded thicker there, and it can withstand a "tighter than usual" standard hose clamp in that spot. You get out on the end of the neck with your clamp and you start to strain that thinner plastic there, pinching it in(bad). Nothing wrong with adding another clamp behind that one, for a side by side setup,,Just don't get greedy out there on the thin end with the clamp pressure.

 

I had the same issue OP......tightened it a little more, and problem solved...I mean it was leaking every time I drove it. Glad you got it sorted out

 

The original spring clamps are more fool-proof. How can you ever be sure you have the correct tightness with these worm clamps?