I have a 2008 Chevy Avalanche 5.3L. The plastic adapters on the firewall that connect the engine coolant hoses to the heater core pipes are leaking (one is but I'll change them both while I'm in there). This is a common problem on these GM trucks.
My QUESTION... Do I really need to drain the cooling system? All the videos I've watch call for this step. But the adapters are at the highest point in the cooling system. Sure I might loose a cup of coolant. So what? The system isn't under pressure because I won't be running the engine while I'm working on it. I guess I should open the radiator just to remove any trapped air pressure.
Draining and refilling the coolant is the longest and messiest step. If I don't have to do it that will cut the time to do the job by 3/4. My coolant was recently changed. It's a mess to drain it, there's no petcock and it's hard to reuse the fluid because most of it ends up on the floor.
Any thoughts, expreience and expertise is greatly appreciated.
P.S. If this isn't feasible could I use two needle nosed vice grips to clamp off the heater hoses?
I don't see why not.
You might have trouble getting the air bubbles out after though.
I get them after draining and filling anyway. Takes several top ups.
Your approach sounds right, but you really need to properly burp the system of air after the procedure.
Thanks all. Will report back. If this works it's a real time/money saver for a common fix.