I just replaced these o-rings. And while you are in there, replace the oil-cooler o-rings as well.

water pump driveshaft seal, N90806302 #9
water pump driveshaft o-ring, N91008902 #10
waterpump gasket 079121119B #3
water pump/thermostat seal, 079121119C #5

oil cooler o-rings (2x079103121AD) #2
Awesome thanks for the info guys. I do actually have the oil cooler o-rings so that’s good. And I bought the entire pump/thermo assembly so I’ll have to look and see what o-rings it has. Looks like I’ll need/want to replace the coolant pipe ones for sure though. Either way thanks again. Got the alternator out tonight and will work on the bracket and oil cooler tomorrow likely into the weekend.
Any idea how much oil I can expect to spill once I unbolt that cooler?
If you have emptied the oil, there will be some but not a gushing amount. I stuffed some towels up there and replaced them half way through the job.
Ed
And if I haven’t drained the oil? Or I should say if I’m trying not to drain the oil - how much bigger of a mess on my hands will there be?
I do not know the answer there, but since it sits higher than the pan you should be able to do it. The manual says nothing about dumping oil, I just happened to be at that stage anyway.
Ed
I’m feeling super stuck trying to get this coolant pump and thermostat off and I’ve got 2 issues I’m hoping to get some help on.
1.) That line which I highlighted in red in my first post really does seem to be in the way. It runs down beneath the pump and it is preventing me from both moving forward and pulling it down to any extent in which I could remove it entirely. So I guess my question is what line is that? And is it safe to remove it temporarily? Or any other suggestions to get this pump pulled out.
2.) While I was able to get the front coolant pipe removed we mangled that rear bolt pretty badly in the process, you can see the pics below with the original bolt on the left. While looking for replacements I thought I had the correct part number - N10124408 - but when the bolts showed up yesterday they don’t look like what I pulled off as they are a touch shorter, have a washer and have a different head. Can/should I use these? Or can anyone point me to a part number for the correct ones?
That line is a power steering line. I am pretty sure all I did was loosen the bracket it is attached to on the engine. I did not drain the PS fluid and disconnect that line when I R&R’d my water pump. If you want to remove it, you will have to drain the PS fluid first, which isn’t a big job, just messy (I hate Pentosin).
The front bolt is N 91032702 M6X16, the rear bolt is N 90780904 M6X20. The difference between them is the length. Neither are available according to an on line Audi parts dealer. FCP Euro has the rear bolt in stock, the only place I could find the front bolt was HS Tuning. Now what you have seems to be pretty close to the stock bolt. Whatever the length difference is, it does not seem to translate into many MM’s and as long as it is less it won’t bottom out. Also the pitch and diameter also seem correct (if you have any nuts to fit the original, use it to spin onto the new part and make sure it spins on easily - or if you have a thread gauge, use that to make sure they are identical), Having said that, unless there are clearance issues, a bolt is a bolt as long as pitch and diameter are identical you can use the new bolt. While the part number you list does not come up as an Audi specific part it is a M6X20 that lists as a Cayenne (Porsche) bolt, as well as Audi and VW.
Ed
Thanks Ed - how did you get that bolt removed from the bracket on the engine? I have the bolt removed on the bracket at the underside of the car which is giving it some wiggle room. However- I see what you mean about the bracket at the top of the engine and I’d like to give this a shot before I disconnect the PS line. I tried getting my stubby ratchet in there with a torx bit as well as a joint adapter but the bolt is well tucked at almost dead center behind that line.
So I have a nice little Blue Point Snap-on ratchet which I would venture to say has an even slimmer profile - but perhaps not. Either way I’ll figure something out. I’m going to get that bolt out and bracket loosened before I try anything else.
Looks like they have a piece that protrudes. The kind I am talking about have the torx bit slide into the ratchet. Kind of like the ratcheting combo wrenches.
Ed
Ended up buying this earlier this morning - should be here tomorrow.
https://www.amazon.com/gp/product/B07YCP213C/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1
That’s real similar to what I have. You can’t get any lower profile than that.
In a pinch I have use a thing small vise grip on just a bit before I got the low profile ratchet.
Ed
Yep - that wrench got it. Still really really tight but after loosening the bracket I was able to move the line vertically just enough to muscle the pump out. Hoping that getting the new one in won’t be half as bad but we’ll see. Should be able to make some headway on it this weekend.
Great news. Yeah I remember is was fiddly getting it in and out, but doable.
Ed
So I had to enlist the help of my neighbor, kick ass guy, but was finally able to get the pump installed this past Saturday. Getting the small hose that attaches nearest the engine and at the same time getting the pump seated correctly on the input shaft was extremely daunting. We really took our time ensuring the pump was seated correctly as I had read fenixgoon’s post on bolting it in and damaging the pump. For me, this job was by far the hardest thing I’ve yet to do to the car. I also wanted to mention that I had the wrong part number for that smaller hose that sits nearest the engine - the correct part number was 07L121081A. The picture showed a small blue tab which threw me off but that ultimately saved me as it kept the tension open on the spring clamp and was likely the only way I was going to get that hose back on as even my long reach flexible hose clamp wasn’t cutting it.
Either way I’m good to go and now have the oil cooler back on with new o-rings as well as a brand new oem alternator. A few more small things to button up and I should finally be able to fire the thing up again. Appreciate all the help as usual!
Great job! Doing the WP is a PITA for sure. Add the oil cooler seals and that only adds to the fun. I disliked that portion more.
Ed
I take it the car must be in service position to do the WP and oil cooler?
Correct.
Ed
I would say yes definitely service position. The oil cooler isn’t too bad - just need to remove the alternator. That water pump though - not fun. Hope you have an easier time than I did. Either way though do yourself a favor and put it into service position.
