What is this hose?

[DaveRad]

Hey there everyone, I’ve been chasing a coolant leak, P0410 and P1126, which may or may not be linked. I recently took a look under the car, and I found those hose disconnected, and I can’t seem to find where it connects to. Anyone have a clue? On the passenger side of the engine bay

[Gilles]

those look to be the power steering hoses..

[DaveRad]

Originally Posted by Gilles

those look to be the power steering hoses..

So, I followed it, and it seems to be the coolant overflow hose. I just topped up the coolant and it’s not leaking as of now, but I noticed it leaking yesterday after driving it. It proceeded to leak below the min line

[elgyqc]

Yes coolant overflow hose, connects to the coolant reservoir in the rear of the engine compartment. Pull up the carpet in the trunk to see if it is wet... likely a coolant reservoir leak.

[obthomas]

More precisely it is a coolant drain hose that drains any overflow from the pocket around the coolant fill and vent relief in the trunk. If you spill coolant while filling or coolant is released through the fill cap it is drained by this hose. If you detect a coolant release from this hose it is likely your coolant cap is bad or you are making more than 20 psi in the coolant system because of over heating. The cap will release pressure over 20 psi.

You need to pressure test the coolant system and make sure it is full. This drain hose is a symptom not a cause of a leak.