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2002 Avalanche-coolant leak

tron guy

Full Member
Joined
Jan 18, 2020
Messages
30
So for more than a year now, every few months I would get a little light indicating that my coolant level was low.

THe place I get my oil changed has a nice top off service, so I just roll in there and get it topped off.

Anyway, it's accelerated lately you might say.

I am getting some spray from the drivers side that shoots up onto my windshield at random times when I am driving. The light comes on more often than it did.

I should preface that last statement by saying I bought some K something or other Leak Stop . $35 I think, haha. Well needless to say, it didn't stop the coolant from leaking.

Anyway, my son and I were looking at where we think the leak is coming from. There are 2 small hoses near the bottom of the radiator on the driver's side. As we are looking at the grill standing in front of the truck it is the left side hose that looks sketchy. It has a 36 on it. The right hose looks normal , the left hose seems to have some white build up or goo . I am assuming that is the culprit. (though not sure).

Anyway, what is the best way that I can determine what hose(s), I need to buy ?
 
I should say there is not a huge puddle on the ground. Where I park at work and at home show signs of a slow leak, or hundreds of drops over the years.
 
Buy or borrow from a parts store a radiator pressure test kit.

I got mine form Harbor Freight and I've found it to be a helpful tool to have.

Attach the tool to your surge tank and on your cold engine, pump the pressure up to 15 PSI and wait.

Your coolant leak will soon make itself known.
 
Get yourself a big piece of cardboard, and park the truck over it.
Check out the cardboard later on to see if there are any coolant drips on it.
Will give you an idea of where the leak is coming from.
Anyhow - on these and many other GM vehicles, there are these crappy plastic heater hose connectors that WILL fail.
Part # is Dorman 800409.
https://www.rockauto.com/en/parts/dorman,800409,heater+hose+connector,6876
You will want to check those and replace if they are wet.
The ones on my truck crumbled like wet cardboard, and let go at an inconvenient time.
So if you don't have a cooling system pressurization tool, just top up your coolant if you haven't done so already, and run the engine until it is good and hot, and start checking all the hoses where they connect to cooling system components.
I bet your heater hose connectors are about to blow.
Very common problem.

CarMech1969
 
X2 on the pressure test. You say you notice it on the lower driver's side if I read correctly. That's where I was noticing it to which turned out to be the radiator. I ended up doing the entire cooling system which was a fairly straight forward job.
 
well I was getting a lot more spray so I ran to my mechanic.

needed a new radiator.

I would say good as new, but I see a few drops coming from the passenger side as the car sits. I always have a habit of dropping cardboard under my truck after someone else works on it.
 
Dorman has metal ones now 800-409HP.. I ordered a pair but have not received them yet so I cant give a review but if there any good you should be able to put a hose clamp on them and not crush the fitting like can happen with the plastic ones..

HVAC Heater Hose Connector | 800-409HP | Coolant Connector - Inlet/Outlet 3/4In. Tube x 5/8In. Hose | Dorman Products
I bought a set and am very happy with them. The go on with a resounding CLICK. The will most likely outlast most everything else on the truck.

https://www.chevyavalanchefanclub.c...em-leak-what-would-you-do.155094/post-2179455

Carid.com had the best price (no pic) https://www.carid.com/dorman/hvac-heater-hose-connector-mpn-800-409hp.html
Rock Auto is where I first saw it https://www.rockauto.com/en/moreinfo.php?pk=12025689&cc=1411894&jsn=779
 
Carid is where I ordered them from on Dec 2, talked to them again yesterday and should have them soon.. Some sort of manufacture data lose on orders.. We'll see...
 
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