Small Leak from Lower Radiator Hose

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Noggles

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So I replaced the entire cooling system a couple months ago because of a leaky water pump and high mileage. Used new continental hoses and a Denso brand stock replacement radiator. Earlier this week I walked out from work and noticed a couple puddles under the core support. After checking it seems to be coming from the lower radiator hose to radiator connection where it slightly pushes out the front of the hose. I reused all the factory spring clamps when I replaced everything but after finding the leak I made sure the hose was pushed all the way on and also added a worm clamp along with the spring clamp but it still leaks. I plan to drain everything next weekend and pulling the hose off to see if the radiator outlet is damaged. What else could cause a leak like this?
 

OR VietVet

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You have already said it. May have a cracked neck and check where the tank and core meet up. Best to pressure test system, while still full, and look real close for where the leak is there and be aware, could be from above there and draining down. Like water gets on your hands and your elbow is below at an angle but the water trails all the way down and drops off the elbow. Good luck
 
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Noggles

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You have already said it. May have a cracked neck and check where the tank and core meet up. best to pressure test system, while still full, and look real close for where the leak is there and be aware, could be from above there and draining down. Like water gets on your hands and your elbow is below at an angle but the water trails all the way down and drops off the elbow. Good luck

I think next weekend I'm gonna drain the coolant and pull the hose off. We used a mirror on a telescoping handle to be able to see it actually coming out of the hose. I originally thought it was where the end met the core but the person helping me could see it coming out of the hose itself.

He mentioned back in the day he would put a sealant on the inside lip of the hose before he put it on the radiator outlet. But I haven't heard of that before and wonder why I would need to if nothing is damaged on the rad itself.
 

mattbta

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Good luck. Had same issue on my Melling water pump - I didn't replace the smaller diameter hoses and had one leak. Fortunately doubling up with a worm clamp fixed mine. I'll replace those hoses and the T's at some point.
 
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Noggles

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Good luck. Had same issue on my Melling water pump - I didn't replace the smaller diameter hoses and had one leak. Fortunately doubling up with a worm clamp fixed mine. I'll replace those hoses and the T's at some point.

So that's interesting you say that. I am also using a Melling pump and the only lines I didn't replace were going to the the t fittings at the firewall since they had been replaced a couple years ago. Those small fittings leaked as well and I had to add worm clamps to those a well. After I added those is when the lower radiator hose started leaking. Melling advertises the pump as standard volume, but could it be too high of volume and causing these leaks?
 
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Noggles

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So a little update but I replaced the lower hose and the clamps today and that seems to have fixed the coolant leak but found the new radiator has a leaking transmission cooler line fitting. It it leaking from where the fitting threads into the radiator so I have an email into the manufacturer now to see about getting it replaced under warranty.
 

OR VietVet

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So a little update but I replaced the lower hose and the clamps today and that seems to have fixed the coolant leak but found the new radiator has a leaking transmission cooler line fitting. It it leaking from where the fitting threads into the radiator so I have an email into the manufacturer now to see about getting it replaced under warranty.
Aftermarket brand radiator or GM radiator?
 
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Noggles

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Aftermarket brand radiator or GM radiator?
Denso.

Got it because it seemed to have equally good reviews online plus has the factory oil cooler provisions for when I add that later. Didn’t even think to look for an oem 2500 radiator lol
 

Joseph Garcia

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Thank you for posting your update and resolving your motor coolant loss issue. Let us know what you find out regarding your transmission cooler connection issue.
 
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Noggles

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So I guess I should update this now that its fixed. New stock replacement (1500 without the oil cooler) AC Delco radiator and also swapped to constant tension worm style clamps and everything appears to be sealed up. There was quite a difference between the transmission cooler line fittings on the Denso radiator versus the AC Delco one. On the Denso they appeared to just thread into plastic thread whereas the AC Delco one looked like a completely different hard to describe style.

The clamps I got from Napa were about 10 bucks a piece but no more spring clamps on the upper and lower hoses. So much nicer now!
 

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