Still Leaking after Coolant Flange Replacement

[Denio24]

Just replaced the coolant flange on a 2003 a4 1.8t. Everything was torqued first threaded in by hand then evenly torqued to 10 Nm. After filling coolant it starts leaking from the back near the flange. Is it possible that it is leaking from the heater hose supply hose? Is the o-ring inside the quick disconnect fitting worn out?

Also, does anyone know the o-ring size for the following part?

[Denio24]

**update** i am led to believe that the replacement coolant flange has a smaller diameter male fitting for the quick disconnect fitting, thus putting less pressure on the o-ring for sealing. Sloppy tolerances in aftermarket parts

[Denio24]

Posted a video showing the actual issue!

[customa4]

Very possible that it's the actual hose/quick connect coupler. This is what mine looked like when it was leaking next to the flange.



This is what it looked like when I removed it.



I was able to stick my phone back there and take the first picture. Get a flashlight and a small mirror to get a good look back there.

[Let it snow]

This makes me think "hotdog down a hallway".

[Denio24]

This makes me think "hotdog down a hallway".

quite brilliant!

[customa4]

Didn't see your other post. Aftermarket parts will surely bite you in the ass. The coolant flange from the dealer is maybe $27, not much money to be saved.

[Abraham535]

I’m 90% sure this just happened to me with the Hudson coolant flange and Rein Hose/quick connect from ECS smh...

[Gosser]

I've used many Hudson/Rein hoses for the heater core hoses and various other rad lines on three 1.8s. All cars are still leak free. But if OEM prices have come down to be competitive with aftermarket, then typically I go OEM. But looking quickly on ECS for the heater core return, the Hudson is 16 and OEM is 91. I'll go Hudson all day long. I would never skimp on the coolant flange though. Regardless of price, I go OEM, I dont bother with the aluminum either, since I've seen the OEM flange last 150,000km+, that a properly installed(not over torqued) flange will last another 150.