2009 I have replaced the Dorman hose (heater) once already with a cheap $8 Y splitter and it broke again. I’ve heard that replacing it with an alunimun “Y” will last longer. My question is, do I need to flush out the antifreeze before I start?
Flushing shouldn’t be necessary just to replace a broken Y. The reason the plastic one broke might be that the connector was over-tightened.
You’re replacing a cooling system fitting.
No need to flush the cooling system.
I did but the pinch clamps this time, just in case
Thanks, I won’t make the same mistake
It’s been my experience that when a fitting breaks repeatedly the root cause is insufficient strain relief. If there’s force on one of the connecting hoses that can be relieved by a slightly longer hose, you may want to do that when you replace the “Y” fitting.
No flush necessary.
When the original Y breaks the hoses must be cut off making them too short to connect to a new Y. It’s best to replace the composite hoses as a complete unit.