DIY B7 Coolant Flange Replacement with Pics

[Andrew149]

Looks like mine is leaking also. Not looking forward on removing the old one.



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[Theiceman]

don't worry its not too bad , just follow my tips and get the required tools. Just Pm me if you want more info. make sure you have a set of torx allen keys. hose clamp removers make it easier too.

[RDA990]

Going to be doing this job soon, I'm pretty sure I'm ready for it since I did my B6 one a while back (biggest PITA). Do we need the other O-rings other than the one that it comes with it? If so does anyone have the part numbers?

[Theiceman]

[IMG][/IMG]

I think you need an oring for the temp sensor maybe as that will have to come out.

the pic posted above is one of the best I have ever seen of the area. shows exactly how it is configured.

[RDA990]

I think you need an oring for the temp sensor maybe as that will have to come out.

the pic posted above is one of the best I have ever seen of the area. shows exactly how it is configured.

I'm looking for the O-Ring that goes into the quick disconnect hose (the one that goes down from the flange). Can't find it anywhere since it's supposed to come with the actual hose but I'm just looking for the O-Ring. I already have the O-Ring for the temp sensor.

[Denio24]

I'm looking for the O-Ring that goes into the quick disconnect hose (the one that goes down from the flange). Can't find it anywhere since it's supposed to come with the actual hose but I'm just looking for the O-Ring. I already have the O-Ring for the temp sensor.

http://www.audizine.com/forum/showth...e-connection-s

[Theiceman]

you know what I don't remember replacing that !!!! I wonder if it sits in the hose and I just removed the old flange and popped in the new one and moved on !! phew , guess I caught a break as it hasnt leaked.

[wding2000]

Not sure that o-ring is for that connector - looks too big. That connector connects downward to hose at below link, secured by a hard wire clip. Not sure there is an o ring.

https://www.ecstuning.com/Audi-B7_A4...oses/ES441709/

[KJack]

I'm looking for the O-Ring that goes into the quick disconnect hose (the one that goes down from the flange). Can't find it anywhere since it's supposed to come with the actual hose but I'm just looking for the O-Ring. I already have the O-Ring for the temp sensor.

I have a brand new flange kit and hoses at home. I'll take the o-ring out of the bottom hose connector and check the size for you and post pics when I get home later. The o-ring that you have circled in the pic is too big for the hose connection; I think the o-ring in the pic is a spare for the neck of the flange that bolts into the engine. The o-ring that's inside the disconnect hose is closer in size to the o-ring that is used for the coolant sensor.

[Der Konig]

The oring for the heater hose and the coolant temp sensor are the same, I have said this a billion times now (slightly exaggerating). I have done this multiple times and they are interchangeable. It is easiest to put the oring on the coolant flange and slide the heater hose over it, other wise it tends to bind up.

# N90316802 CTS/Heater hose o-ring

https://journalbearings.wordpress.co...nt-flange-diy/

[wding2000]

The oring for the heater hose and the coolant temp sensor are the same, ....

Good to know. Thanks for saying it one billion+1 times

[Der Konig]

Good to know. Thanks for saying it one billion+1 times

No problem and god speed, its a pretty straight forward DIY and it will blow your mind how quickly you can do it after you have gotten through it once.

[Theiceman]

The oring for the heater hose and the coolant temp sensor are the same, I have said this a billion times now (slightly exaggerating). I have done this multiple times and they are interchangeable. It is easiest to put the oring on the coolant flange and slide the heater hose over it, other wise it tends to bind up.

# N90316802 CTS/Heater hose o-ring

https://journalbearings.wordpress.co...nt-flange-diy/

im sure I have only read it about half a billion times so I am sure you are exaggerating.

but you are correct its a very straight forward DIY if you have the tools . im not sure what all the fuss is about sometimes.

[RDA990]

I read a recent thread of an AZ member that just tried to remove his flange and ran into a really bad wall. He didn't seat the torx bit and used a size too small, he used a T27 instead of a T30. I don't know his reason for the bit he chose, but I can attest that the T30 is going to be the one to use (if you have the triple square then it should be a M8). On top of using too small a bit, he somehow didn't seat the bit as directly as possible and stripped the head on the bolt towards the driver's side - which is slightly more challenging then the other of the two. Here's the pic from his thread.
Not good.

3 hours into the job and this just happened. Stripped the driver side T30. Trying to figure out all the ways I can get it out without dropping/pulling the engine. There is absolutely no space in there. Going to start by taking out all the PVC and vacuum pump stuff out of the way.

Did my B6 coolant flange and it was a complete PITA, the B7 coolant flange is PITA x100.

[KJack]

3 hours into the job and this just happened. Stripped the driver side T30. Trying to figure out all the ways I can get it out without dropping/pulling the engine. There is absolutely no space in there. Going to start by taking out all the PVC and vacuum pump stuff out of the way.

Did my B6 coolant flange and it was a complete PITA, the B7 coolant flange is PITA x100.

How did this turn out? Were you able to get things taken care of?

[Spridle]

I just finished this job. And yes it sucked donkey balls. Oddly I had no problem removing or putting the two bolts back in. But getting the hose off the drivers side SUCKED. I have no idea how long I messed with that. Get that hose, cut it, move on with your life. Get a new O ring for the bottom hose too. Ughh.

[Andrew149]

[IMG][/IMG]

I think you need an oring for the temp sensor maybe as that will have to come out.

the pic posted above is one of the best I have ever seen of the area. shows exactly how it is configured.

Thanks for putting instructions on the picture looks much easier now.

[.RJ]

I tackled this job last week, it was as awful as I expected it to be. I did not remove the vacuum pump or line, wiring harness, but did buy new flange hoses, and the hose that connects the upper & lower hard pipes and removed that one. This allowed me to unbolt the upper pipe and pull the whole thing out with the coolant flange, and with the hose connecting the upper & lower hard pipes that gave a little more room to reach around to the back of the motor to unbolt the flange. I think I spent half my time scraping rubber off of the hard pipes though, the hoses had really fused to those things. Hope this helps someone.

[Dluvr22]

Did this last night. I purchased the kit from ECS Tuning with the housing, sensor, o-rings, etc. I got home from work and the package had been left at my door. Well I decided not to wait and get it done immediately. Kudos to you guys who did it with out moving the vacuum pump housing because I could not have done it without moving said pump.

Couple of things. I did not complete this til 5:20 AM this morning.
The birds were chirping as I was heading upstairs bone tired to take a shower and hit the sack.
Not only that but after I took the whole housing assembly off and began assembly of the new one, I realize my leak was not coming from where the flange connected to the engine but rather my sensor o-ring was the culprit instead.
I could freely twist the old sensor around in the housing while the clip was still on.
Seems to me I could have just pulled the clip and replace the sensor in a few minutes and my problem would have been solved but I'm still glad I got the whole thing out as I now have peace of mind knowing it is done.

TIP:
I did not have a right angle T-30 torx but I worked around that by sticking an appropriately sized Allen wrench in the 1/4" bit to get the flange bolts out. That work like a charm.

[Okedokey]

I have the manifold off right now (s3 injector install and carbon clean); much better access by the look of it. Worth doing the flange and thermostat?

[dwinters14]

Did this the other day. My process:

I bought a really slim 1/4 ratchet that could accept drill bits and 1/4 drives as well as a slim ratchetting screw driver that accepts drill bits.

I removed the 10mm nut behind the flange that has two ground cables on them and pushed them to the side. I then pulled the coolant temp sensor out with the O-Ring and let that hang.

Now disconnect the lower heater core hose. Mine broke because the O-Ring that's inside was swollen and the plastic piece that holds it in place came out. Just an FYI I had to fit in a new one from an O-Ring kit.

From this lower hose a bunch of coolant will drain so have a bucket with a big splash pan underneath the back part of the engine.

Remove the first bolt on the passenger side holding the flange to the block.

Now remove the single philips screw on the coolant reservoir and move that to the side.

Stick your screw driver in and remove the other bolt. This may take a little while so be patient.

Now on the flange there's a T where the flange meets a rubber hose then the hard pipe. Leave this attached as it's a royal PITA to take off. Now there's another hose to the right that has a clamp over it. Remove the hose clamp and pull this hose off the hardpipe.

Now remove the coolant hard pipe from the top of the engine. There should be 3 bolts and two coolant lines to remove including ^ one.

Pull the whole assembly out and replace the flange.

Install is just the reverse.

[Okedokey]

What is the part number for the slut-hose that is glued to the metal hose?

Cheers

[Andrew149]

Rear coolant flange was a pita


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[redbat]

Just completed this rather epic journey, and I have a problem that hopefully someone will be able to help with. Due to my previous super leaky vacuum pump, the rubber hose on the bottom of the coolant flange had developed a nasty bubble, so I replaced that hose as well (connects to heater core next to battery).

The issue I'm having is that the car will not start after being buttoned up. Got code P0118, my OBDII app was showing that the car was reporting coolant temp of -40, which is obviously not correct in late summer in Northern California. Pulled the connector off of the (new) coolant temp sensor, and noticed 2 things - the inside plastic parts around the pins are cracked and loose, AND the housing will not "click" onto the sensor, so it could fall off when driving.

I'm guessing it got whacked somehow when I was pulling the hose through the firewall. Checked ETKA, and it looks like the part is 8K0 973 702, which is fine, but I don't know a) where that wire ends up, and b) how I'm gonna replace it in the first place, as it's not in a super accessible location.

Anyone had to deal with this before? Any tips?

[Theiceman]

So you are saying the wiring harness is damaged ? Can you find a similar connector at a wreckers ( take your old sensor with you for test fit ) and cut and splice it in ?


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[Theiceman]

Also did you make Sure your ground bracket was snug on the back of the vacuum pump/timing cover?


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[redbat]

So you are saying the wiring harness is damaged ? Can you find a similar connector at a wreckers ( take your old sensor with you for test fit ) and cut and splice it in ?


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Yeah, the connector is broken on the inside AND the locking tab snapped off. AND there's a break in the wire insulation for one of the two wires, leaving part of the wire exposed. Here's the connector:



Here's the wire:



I don't even know if the wire is connected on the other end or not - I'm going to just try to fix what I can see and hope for the best. Dealership sold me the replacement connector for $6, and I'll wrap that single exposed wire and then wrap the pair. The oil from the vacuum pump leak disintregrated the ribbed plastic cover over the wires. Hooray.

And yeah, I triple-checked the ground connector on the vac pump - it's in correctly and on there tight.

[redbat]

Update: Fixed! Took apart the old connector and the 90 degree dealie attached to it, wrapped each wire, plugged the wires/terminals into the new connector, put everything back together and it started.

Almost had a heart attack because the radiator fans were on full blast, but then remembered that I still needed to clear the P0118 - did that and all is well now.

Moral of the story: be VERY careful with that electrical connector to the coolant temperature sensor - you do NOT want to have to replace that thing - it's super fiddly to do with almost no clearance, and it has to be done at arms' length because you can't pull the connector toward you very much.

[Audi5gs]

Good afternoon, going to be trying this myself. I want to cut the hose in question, but the provided part number: 06D121065L is actually #6 to your diagram, and is the hard-pipe and not the hose that connects to it. Does anyone have the part number for the hose? I thank all of you in this thread for all of your information, studied every post like it was my job. Thanks again.

[KJack]

Good afternoon, going to be trying this myself. I want to cut the hose in question, but the provided part number: 06D121065L is actually #6 to your diagram, and is the hard-pipe and not the hose that connects to it. Does anyone have the part number for the hose? I thank all of you in this thread for all of your information, studied every post like it was my job. Thanks again.

Here is the short hose that connects the flange to the hard pipe (06D121101B): https://www.ecstuning.com/b-genuine-...se/06d121101b/

And here is the longer hose that connects the flange to the coolant supply (8E1819371T):
https://www.ecstuning.com/b-genuine-...se/8e1819371t/

[Audi5gs]

KJack,

Thank you my friend...

Everyone else, I took the day off from work today. I only did disassembly today, tomorrow will be re-assembly just because my parts are getting delivered tomorrow. I was able to get everything out within an hour, and I really didnt have to remove much. I'll hit you guys with my advice:

-I went right at the coolant reservoir, you need that elbow room
-Coolant temp sensor was next
-Heater core hose with clip, I saw some guys struggled with this, I was able to get both my arms in on the pass side and just wiggle out evenly, came out like cake
-Removed Coolant hose on the metal hard pipe in the front
-Unbolted the hard pipe with the rear two rear hoses still attached.
-Used a good size pick on the hose not attached to the flange. What was nice about it being unbolted from the top of the motor, was the ability to move it and get the pick around.
-Just got in there got both bolts out in under 10 minutes with the nice flat wrench kit that you guys posted on here.
-Pulled flange and hard tube out still attached one piece, and done.

Additional notes:
-A set of good size picks will change your life on these coolant hoses
-The coolant host clamp tool, my god, game changer.
-The ratcheting flat wrench set... MONEY!
-Didnt remove air box, any electrical, vac lines, vac pump are all in place still.
-I'm 6' 205LBS, so my hands aren't tiny, but aren't giant, I would just say, you really need to be able to get your forearms in there good, laying on top hugging the motor, gave me the perfect positioning.
-I'm gonna try and post pictures, but I don't have a site that hosts, but I'll put them up on my Google for everyone.
-Last but not least, couldn't have done it without all you guys sharing your experiences, shortcuts, knowledge and love and hate for your B7's, dont get discouraged, just go in there and keep calm. The right tools and mindset are key.
-07 B7, Northeast car its entire life, first time done at 120K

Let's just hope tomorrow, we put everything back in the same order without issue.

Peace,
J

[RDA990]

3 hours into the job and this just happened. Stripped the driver side T30. Trying to figure out all the ways I can get it out without dropping/pulling the engine. There is absolutely no space in there. Going to start by taking out all the PVC and vacuum pump stuff out of the way.

Did my B6 coolant flange and it was a complete PITA, the B7 coolant flange is PITA x100.

How did this turn out? Were you able to get things taken care of?

After 2 years the stripped coolant flange bolt is out and the leak is finally fixed. The flange wasn't in bad shape, it was the O-ring that failed causing the leak. The coolant reservoir cap had to be opened after every drive for the past 2 years to relieve the pressure or else coolant would leak through the flange.

Since one of the bolts was stripped I had to use a bolt extractor:



I went through 2 or 3 of them until I realized I had to break some of the flange plastic to expose the bolt head a bit more so the extractor could have a better grip on it. It helped that I was also doing the valve cover gasket, PCV, and cam follower so that gave me some more space on the HPFP side. This is where this came in handy:



After breaking some plastic off the extractor easily took the bolt out. I couldn't have done it without these tools either:





Old coolant flange and stripped bolt:




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[wding2000]

Two-year old striped bolt - finally

[mafel22]

Good afternoon all...

I was driving down the highway when my temp gauge spiked quickly. Pulled over, let her cool down and found this. Can't tell exactly what's broken. Is there a quick disconnect style part in between the heater hose and the coolant flange (or attached to the end of the hose)? Or, is the lower part of the flange busted off inside the hose?

Heater hose coolant flange.jpg

Heater hose coolant flange 2.jpg

If it's a disconnect or hose, I would just replace that part. If not, I assuming I should plan to replace the the whole coolant flange (with kit) correct?

08 A4 B7 2.0 Quattro 122k miles

Great write up and comments. I apologize if this was answered already,but I couldn't find it on the diagram or in a posting. Newer member here - really appreciate all the detailed info!

Thanks everyone,

Matt

[ahotboy15]

if u do, dont forget extra o-ring

[mcpcartier]

Good afternoon all...

I was driving down the highway when my temp gauge spiked quickly. Pulled over, let her cool down and found this. Can't tell exactly what's broken. Is there a quick disconnect style part in between the heater hose and the coolant flange (or attached to the end of the hose)? Or, is the lower part of the flange busted off inside the hose?

Heater hose coolant flange.jpg

Heater hose coolant flange 2.jpg

If it's a disconnect or hose, I would just replace that part. If not, I assuming I should plan to replace the the whole coolant flange (with kit) correct?

08 A4 B7 2.0 Quattro 122k miles

Great write up and comments. I apologize if this was answered already,but I couldn't find it on the diagram or in a posting. Newer member here - really appreciate all the detailed info!

Thanks everyone,

Matt

Your hose from the heater core snapped...you'll need a new hose. I'd throw in a new coolant flange at the same time (since your coolant is drained).

BTW....just pull out that metal retainer and the hose to the heater core (what's left of it) will slide down. New hose will come with o-ring held in place so no worries on that front.

looks like you need this....https://www.ecstuning.com/b-genuine-...se/8e1819371t/

[TWiST]

It's funny this thread has been bumped back up as I had a question that someone here may be able to answer. The electrical connector on my coolant temp sensor is broken and does not click into place, so every time I push it back on it eventually pops back off and its really not a huge deal, the fans just run at full speed when its disconnected, but I wanted to try to resolve it once and for all. I saw that @Redbat had replaced the connector and said he got it from the dealership, does anyone know the part number for it? I order 1J0973722 from Amazon but I am not convinced it is the correct part, I will find out on Thursday but if anybody had the correct part number for the electrical connector that would be fantastic!

[redbat]

Part number is 8K0 973 702. Hindsight being 20/20, I'd probably get replacement wires with terminals, install them in the new connector, cut old connector off and then just splice. I didn't have time to wait, so I had to remove the existing wires from the broken terminal and install them in the new connector. Huge pain in the ass, because the existing wires are super short.

[TWiST]

Part number is 8K0 973 702. Hindsight being 20/20, I'd probably get replacement wires with terminals, install them in the new connector, cut old connector off and then just splice. I didn't have time to wait, so I had to remove the existing wires from the broken terminal and install them in the new connector. Huge pain in the ass, because the existing wires are super short.

Thanks for the quick reply, much appreciated! It looks like the one I ordered is extremely close, but not the exact same connector. I have some electrical connector tools, so I am hoping I will be able to disassemble it and just slip the old wires and everything into the new housing as I do not believe the wires are damaged in my case. Luckily when the connector slips off its not the end of the world, just the engine cooling fans go to full speed and my car does not get a proper warm up cycle, but as long as I give her a little gas as I idle it all works out, I am just getting tired of having to reach in the engine push the connector back on and clear the code.

Thanks again for getting back to me so fast man!

[dalmation53]

if u do, dont forget extra o-ring

Don't forget to pay the turbo you stole before recommending.

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