Coolant pump help

I’m trying to get the coolant pump/thermostat removed as I have a replacement but I’m struggling to see how it would pull out. Bentley says to remove the front coolant pipe which needs to have the alternator removed first (I’m also in the process of replacing that too) but the line highlighted in the picture I can’t determine what it is and it definitely appears

to be blocking me from pulling straight out from the front. Any ideas on what that line is and if it does need to be removed? Also anyone happen to have any part numbers for any replacement o-rings? For the front coolant pipe or if any are need to where the coolant pump bolts back up.

That pipe does not get removed. The silver one does. The pump pulls forward then down.

It’s been a while but I believe I may have loosened the bracket above on that hard line to give me some more room.

Unfortunately I did not take any pictures of that job.


Ok thanks for the feedback. Do you happen to remember if you replaced any o-rings? Either behind the coolant pipe or the pump itself?

I replaced all O rings for any parts removed. I believe the pump came with them but I am not sure.


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

Coolant pipe is #31
#32) o-ring 07L103121N
#33) o-ring WHT000881

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.


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.


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?

  1. 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).

  2. 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.


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.

I think I used one of those low profile ratchets similar to this:

Low Profile Ratchet


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.


Ended up buying this earlier this morning - should be here tomorrow.

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.


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.