B7 2.0T Quattro Coolant Flange

[DFMAGuy]

Looking for additional insight as I am mid-point on this task ...

I finally got around to dealing with the Coolant Flange replacement on my 06' B7 2.0T Quattro but before starting had read a lot of past posts.

Four questions that I didn't see answers for in the reading so far:

1. Is the o-ring for the Heater Core Return Hose snap connect fitting the same o-ring that is used when replacing the Temp Sensor (sure seems to be) ?

2. What is the design application purpose of the round hard black plastic ring that came up on the defective and now removed Coolant Flange that attaches to that same Heater Core Return Hose snap connect fitting ?

3. Why does this same round hard black plastic ring seem to prevent enough penetration for the new Coolant Flange (pull back clip on the Heater Core Return Hose snap connect fitting is "not reaching" the lock grooves on the Coolant Flange) ?

4. Doesn't look to hard to switch out the Heater Core Return Hose now that I'm this far ? Is that true ? I'm think I should because who knows if I might not of cracked it trying to seat the pull back clip on the Heater Core Return Hose snap connect fitting !

Thanks for any advice out there before I put this all back together as I sure don't want to do this one again - I thought the flex down pipe off the Cat was a tough one but this one is tougher for sure (I did remove the Vac Pump to get at it somewhat).

[Older_not_Wiser]

https://s20.postimg.org/klceky1i5/20170625_191853_zps6o31dtef.jpg

1) I did not compare them when I replaced mine, but I think they are.
2) Not sure what you are speaking of. I do not think there was any loose ring on that connection. Did a piece of the old coolant flange break off?
3) A broken off piece of the old flange may explain this if you are trying to put it in there
4) Two schools of thought here a) if it aint broke, and b) do not ever want to go back in there to fix anything else. I chose a).

Maybe if you can provide a picture of your old coolant flange and the ring you speak of we could better understand what you are seeing.

[EvolutionArmory]

There is no sealing ring for the quick disconnect connector.

A lot of people replace the heater core hose at the same time. I did not need to when I did mine.

[lyates1987]

The quick disconnect you speak of, also known as a coupler (connects to the hose then the flange) should have the ring already inside it. IIRC I think you need to buy a new coupler for that specific O-ring. I have not seen that O-ringsold separately but I could be wrong.i The temp sensor o-ring is thicker.

[DFMAGuy]

Thanks very much.

Ended up with more time on my hands than I thought today and had my Auto Zone guy bring in a Rien Heater Core Return Hose from another area store to take a look at it.

I can see now that the black plastic ring is a press fit second piece in the Heater Core Return Hose Coupling and serves the purpose of entrapping the o-ring that seals to the Coolant Flange - My removed Coolant Flange looks very much like the B7 Flange you are showing me on the left, lots of "wear and tear" - I think I'll switch out the Heater Core Return Hose while I'm at it - Fitting those two items up on the bench they lock together very nicely and the compression on the fresh o-ring feels great.

Appreciate your taking the time to assist me.

I want to get this job over with so I can start into my 07' Q7 "new to me" purchase I picked up in VA yesterday - I don't have much Garage space, its not heated, and its getting cold here in the Northeast.

Cheers.