Coolant Leak

[colbythekid]

Hello Everyone

I have a coolant leak that I can't seem to locate. I thought it was the crossover pipe but the valley is dry at the front of the engine under both sides of the crossover pipe. I don't think there are any other coolant lines running in the back of the engine are there?

When I squeeze the radiator hose I don't hear any leaks. Just the pressure going out to the overflow tank.

 

[Big T]

Check the heater hoses where they attach to the heater core at the firewall. This will be right over the turbo down pipe. Probably have to remove the inner fender on passenger side to get a good view. I just had to replace these hoses up to the "Ts" in your second picture. Those are your coolant lines at the back. The line from the lower portion of reservoir intersects the lower coolant hose on passenger side connecting the radiator to the water pump. I had to disconnect that to remove water pump and timing cover, but this leak looks further back. Sorry you are having to chase this down.

 

[Will L.]

Check with local auto parts stores near you; they have a tool loan system where you buy it, use it, return it and get $ back. Squeezing the hose with your hand is right idea but not enough pressure. Get a pressure tester kit. Try to get the adapter to test your radiator cap at same time (not all places have that adapter as loaner). You attach the pressure tester in place of the cap and use the pump to bring system up to max operation pressure which is 16lbs for your rig. Then it will be a constant supply and help you find the leak easily.

Then after you fix the leak, test the radiator cap while you have the tool. You just hook the cap to the pump with the adapter and slowly pump it up. It should hold at 15psi, but when you hit 16 should start dumping pressure out the cap. This is the most common failure part of the cap.
The vacuum test is the other part of the test, but need a hand vacuum pump for it. simply you hook up the vacuum pump to the same adapter and attempt pulling a vacuum. The cap should instantly open and not allow any vacuum to build. But even if you can’t do the vacuum test, doing the other while you have the loaner tool is a smart idea.

 

[MrMarty51]

Throw a large size piece of cardboard under the truck. That massive of a leak should not take too long to tell where the drips are emanating from.
Cardboard also makes for a mighty fine creeper too.
Body shops usually has a fair supply of larger chunks and also furniture stores.
If the leak seems to be coming from forwards of the enjun, check the timing cover coolant ports for drips around the gaskets. Thats where mine was dripping frum.

 

[JMJNet]

If it is a suburban, there are some quick connect under the passenger side near the frame.
I am not sure if it goes that far but if that one leaks, it will puddle everywhere and it is the lowest point of the cooling system.

Mine leaks there at one time.

 

[Big T]

If it is a suburban, there are some quick connect under the passenger side near the frame.
I am not sure if it goes that far but if that one leaks, it will puddle everywhere and it is the lowest point of the cooling system.

Mine leaks there at one time.

Yeah those are for the rear heat. Easy to check. They’re above the connection of the down pipe to the rest of the exhaust.

 

[Big T]

Talked with Colby. Coolant leak was at the passenger side of the coolant crossover. Cleaned that up, resealed and no leak.

He drove it an estimated 25 miles today. Had one instance of a stall early on and swapped the PMD, which fixed that issue. It’s running good.

Replacement IP has been ordered. We’ll install it Thanksgiving week. We’ll pull the PMD off it and mount it to one of our heat sinks for remote mounting.