# TT MK2 Vacuum Pump Leak (BWA 2L TFSI Engine)



## Hadaak (Dec 25, 2008)

I noticed a minor leak as per the pic. Any ideas?


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## Hadaak (Dec 25, 2008)

no hints. mmmm I will have to go ask Elsa about his aprt of the engine then.


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## TT-driver (Sep 14, 2010)

I think it's the unit for the variable camshaft, or is it part of the vacuum pump for the brake booster?

I'd try to fasten the screw a bit more.


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## Hadaak (Dec 25, 2008)

Leak is getting serious. I think it has to do with the coolant liquid connection. I will try to isolate the leak. I had a coolant leak issue back in at about 2010 12.000 km when the expansion tank was almost empty. Audi dealer couldn't find an issue and refilled it. I guess the issue is coming back. When I check yesterday the coolant is way below minimum.


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## Hadaak (Dec 25, 2008)

Helpful doc here containing info about the bwa engine: 
http://vwts.ru/engine/axx_bwa/axx_bwa_20_fsi_eng.pdf

If link does not work copy and paste in your browser.


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## Hadaak (Dec 25, 2008)

I think the leak is coming from the water connection on the pic.


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## Hadaak (Dec 25, 2008)

I suspect this guy:


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## Hadaak (Dec 25, 2008)

Cooling flange. Part number 06F121132G. That's number 56 on the pic. Seems to be a common cause for coolant leak according to google and the some VW forums.


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## Hadaak (Dec 25, 2008)




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## Hadaak (Dec 25, 2008)

The G version was replace by the H version starting from January 2011.


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## Hadaak (Dec 25, 2008)

After additional checking I found the leak. it's the vaccum pump.


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## Hadaak (Dec 25, 2008)

The whole pump should be replace even if the culprit is the seal on the external side.
the seal is not sold separately so I have 3 solutions:
1. come up with a custom sealant from some hardcore material => someone mentions RTV sealant on the VWVortex forum 
http://forums.vwvortex.com/showthread.p ... -Pump-Leak

2. get a new pump and replace the whole unit
3. get a new pump and change the sealant only. The new pump is a new version so not sure this will work.


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## Hadaak (Dec 25, 2008)

Anybody know why this pump is not serviceable? I mean you cannot change the seal so why was it made to be opened knowing that opening almost anything with a seal in a car means changing the seal !!! Plus there are a lot of cases of leaking VW vacuum pumps on the net. Why doesn't VW put the damn seal/O-ring for sale?
I guess I'll just open it and JB weld the cover back :x


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## Hadaak (Dec 25, 2008)

BMW sells both seals. Engine side and external cover side.


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## TT-driver (Sep 14, 2010)

Hadaak said:


> Anybody know why this pump is not serviceable?


VAG mechanics lack the skills to fix something. They only know how to replace :wink:

By the way, hope you and the people around you are OK there in Paris.


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## Hadaak (Dec 25, 2008)

TT-driver said:


> Hadaak said:
> 
> 
> > Anybody know why this pump is not serviceable?
> ...


I'm good TT-Driver, thanks. Family is ok too. Hard times over here


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## Hadaak (Dec 25, 2008)

TT-driver said:


> Hadaak said:
> 
> 
> > Anybody know why this pump is not serviceable?
> ...


Only thing I can think of is they didn't seal the damn thing completely because you might need to remove the external cover in case something goes wrong inside the pump to have access to its internals and unlock/remove it.


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## Hadaak (Dec 25, 2008)

But I will go the RTV sealant way first. i don't want to shed the 280€ for a damn seal. Why throw a good pump because of the seal. this is stupid. I even thought of welding the external cover completely but like I said I might need to open it in the future if something goes kaput inside. So I'll just open it and use the RTV sealant it for the moment.


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## Hadaak (Dec 25, 2008)

some more material :


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## Hadaak (Dec 25, 2008)

As per the video I don't see why there is any oil in this pump in the first place !!!!
some blowby maybe but there shouldn't be any enormous oil flow/pressure in there. so an RTV sealant will do the job.


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## Hadaak (Dec 25, 2008)

ordered this:


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## TT-driver (Sep 14, 2010)

Good to see you're all OK. Hang on in there, stand tall!

That sealant stuff: that would be my way forward too.

Welding would be too tricky. Heat can distort the casing.


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## Hadaak (Dec 25, 2008)

Not I will remove the pump from the engine or just remove the cover. If I remove the pump I'll have to change the o-ring located between the pump and the engine. I guess it's easier to just leave the pump where it is is and work on the cover only. On the other hand removing the pump completely will make it easier to prep and seal....


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## TT-driver (Sep 14, 2010)

Hmmmm I'd leave it in place.... one less seal to worry about.....


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## Hadaak (Dec 25, 2008)

I think I'll leave it on. The leak is certainly a minor one on the lower side. 
I will remove it if the RTV fix does not hold in the future.


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## Hadaak (Dec 25, 2008)

Great video for applying rtv silicone and very funny at some points. Very professional.


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## TT-driver (Sep 14, 2010)

I really like that suggestion of how to remove grime from the screw holes.


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## Hadaak (Dec 25, 2008)

and the use of the studs to make sure the oil pan goes right in place. I'm gonna use that for sure.
The gun and the "hey dad" part were a very funny touch in the serious procedure


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## TT-driver (Sep 14, 2010)

Indeed those studs, but I knew that one. The hey dad part.... I can remember those moments with my dad. 40 years ago when my father wanted to make sound recordings of me having talks with him, I was more interested in the tape deck and the microphone than the whole conversation. Listening back those recordings is hilarious :lol:

My dad also had to lock his toolbox. I started using his tool to take various things apart. Great fun for a 5 years old, not so great for the parents....


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## Hadaak (Dec 25, 2008)

old times


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## andez1781 (May 27, 2015)

Hay , just a note on that vid if you're going to do that access cover that is way to much sealant . (even for a sump) you don't want any pushing out on the inside as there will be a chance of it coming away and blocking internal oil paths . the auld alliance !! Vive le France ! ..


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## Hadaak (Dec 25, 2008)

Thanks for the tip. I know I won't need much sealant since the leak is not that important. I will keep the original seal and just put some rtv on the outer lower side of the pump cover. I'll have more info when I open it up. Like you said Vive la France


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## WoRkZ (Sep 19, 2015)

If there's a leak, you should seal the whole thing up (not just smear a bit of liquid seal on part of the cover)... or the oil might simply leak out from just a bit further up the seal you have made. Also, you need to flush all the oil, clean things up, then seal, then put oil back in. Good luck and let us know how it went.


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## Hadaak (Dec 25, 2008)

Like I said before there is no oil in there. It's a vacuum pump. At least that's what I understood. It is used by the brake boister. I don't really know where the leaking oil is coming. The pump is connected to the camshaft so this might explain some oil getting through. I also think that this leak is probably a consequence of the low oil pressure warning i used to have before replacing the pcv. The seal was probably stressed by the malfunctioning pcv. I will remove the cover, clean everything, put a tinay line of rtv around the origina seal and tigbten it up. There are no torque specs for the cover screws as they are not supposed to be removed. I will update this thread with pics of the operation and later on with some feedback after some km.


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## Hadaak (Dec 25, 2008)

OK So new foundings:

1. Vacuum pump needs oil. so oil flows in there. a lot apparently.
2. Vacuum pump can go bad for different reasons  I guess mine is suffering because of the way I brake. I tend not to keep my foot on the brake pedal when nearing a stop. I apply, release the brake several times, well not too many times though, and this can lead to wear on the vacuum pump. I do this so as not to put too much strain on the brake disks and the brake pads so they don't get hot.

here is a good video of how it works:


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## Hadaak (Dec 25, 2008)

Just opened the pump. The leaking side has metal touching metal with plastic seal completely squeezed back in its seat. This is the lower part of the pump. The sealing is really bad on this pump.


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## Hadaak (Dec 25, 2008)

leak repaired with rtv silicone. here are some pics of the operation. I will test drive after 24 hours, that's how long it takes for the RTV to completely cure according to the instructions:










Pics are here:

http://s664.photobucket.com/user/hadaak ... k%20Repair


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## Hadaak (Dec 25, 2008)

I applied a tiny line of rtv at the outer edge of the cover (outer side of the oem seal). This way the extra rtv will be squeezed around the oem seal and I hope won't reach the inside edge of the pump.


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## TT-driver (Sep 14, 2010)

And? Vacuum on the booster OK and no leaks?


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## Hadaak (Dec 25, 2008)

Test drove it today after 22H of rest (yes I almost respected the 24 hours curing period ). No leaks. Braking is OK. So far so good


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## Hadaak (Dec 25, 2008)

For the record TT is 97500 KM old. 
We'll see how many KM the patching I did will hold.


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## TT-driver (Sep 14, 2010)




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## Hadaak (Dec 25, 2008)

looks like my patching won't be holding long. There is no apparent oil on the engine beneath the pump but when rubbing my finger on the underside of the pump I found traces of oil. I have cleaned this part when I reinstalled the pump. This means I will have to re-think the patching. next step is re-tighten the screws as I didn't do that after the 22h RTV cure.


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## TT-driver (Sep 14, 2010)

100% sure it's not from the cam cover seal? Just double checking. I'd expect a liquid seal to work properly first time. It works on the sump exactly the same way.


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## Hadaak (Dec 25, 2008)

no leaks detected from the cam cover seal. What makes me think it is still the bottom side of the vacuum pump leaking is that before there was visible oil on the engine and the wires underneath the pump. now the engine is clean since I did the patching but when I pass my finger under the bottom side of the pump I find oil traces. so the leaking diminished considerably but it is still there. I guess this was also caused by the fact that I applied the rtv over (on the outside) of the oem rubber seal. I should have removed the oem rubber seal and completely and replaced it with the RTV. What I will do next is get a BMW seal since it looks like the one on the TT but it is all round, squeeze it in place and test it.

BMW vacuum pump seal


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## Hadaak (Dec 25, 2008)




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## Hadaak (Dec 25, 2008)

not sure of the size but I will try either getting the BMW seal or something similar or even bigger diameter and then cut it to fit in the pump and seal it with some rtv on the upper side.


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## Hadaak (Dec 25, 2008)

TT seal:


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## Hadaak (Dec 25, 2008)

or just get something like this ((HIGH TEMP) O-RING CORD) with the right diameter and use some RTV to join it.

http://www.ebay.co.uk/itm/NEW-VITON-75- ... uU-6Zp_AvA


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## Hadaak (Dec 25, 2008)

or make my own with high temp RTV 

http://www.instructables.com/id/Homemade-silicone-O-rings-and-tubing/


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## TT-driver (Sep 14, 2010)

I love this French attitude to DIY fixing  
Keep up the good work!


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## Hadaak (Dec 25, 2008)




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## Hadaak (Dec 25, 2008)

So I went ahead and removed and re-rtved it it again with a thicker line right above the oem seal. I've used the TT the whole week and so far no leaking and no traces of oil.


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## brittan (May 18, 2007)

Yes, vacuum pump.
Can you find a place that sells seal, bearings etc and identify an O-seal that fits?


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## Hadaak (Dec 25, 2008)

I measured the diameter and width of the seal. I will look around for a replacement soon. For the moment the rtv patch is ok.


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## Hadaak (Dec 25, 2008)

Just a quick update here. 4000 Km later and the RTV patch is still holding fine


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## brittan (May 18, 2007)

[smiley=thumbsup.gif]


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## Hadaak (Dec 25, 2008)

33.000 Km later and the rtv seal is still holding


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## Hadaak (Dec 25, 2008)

49.000 km later and still holding


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## Hadaak (Dec 25, 2008)

I discovered a hissing sound today near the brake pedal. So I think the brake booster is leaking. 
I will clean the old RTV patch and re-apply a new one, then replace the brake booster if it is really on it's way out.
I have a tiny oil leak I cannot trace to anything !! 
It is like the vacuum pump or the valve cover is spurting oil on two wiring looms which are far from any oil parts !!! I will put a camera in the engine compartment to see where the oil is coming from.


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## Hadaak (Dec 25, 2008)

These guys are selling accum pump re-seal kits:


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## Hadaak (Dec 25, 2008)

Volvo have a kit which looks the same as the one on the TT:


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## andez1781 (May 27, 2015)

Well done hadaak, getting three years out of your fix is a plus for me to you. Can you post a pick of your oil leak location area . Valve covers are known for working loose ..


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## Hadaak (Dec 25, 2008)

Thanks. I will upload pics later.


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## Hadaak (Dec 25, 2008)

No modifications to make. The RTV is holding solid. Checked the vacuum pump for leaks last night, nada.
So no pics :lol: :lol: But I keep the RTV in the tool box just in case.


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## Hadaak (Dec 25, 2008)

160.000 km


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## Wolvez (Jun 22, 2018)

You just need to replace the o rings


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## Hadaak (Dec 25, 2008)

I don't have any issues with the rtv. The big o-ring is not for sale. As a separate item.


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## happychappy (Feb 9, 2015)

I wonder why an O ring kit is not readily available?

A replacement pump from VAG is £230 plus VAT in the UK!


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## Wolvez (Jun 22, 2018)

happychappy said:


> I wonder why an O ring kit is not readily available?
> 
> A replacement pump from VAG is £230 plus VAT in the UK!


You can buy o-ring kit at RKXtech


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## happychappy (Feb 9, 2015)

Costs a small fortune though!

Why on earth don't VAG dealers stock the parts....


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## Hadaak (Dec 25, 2008)

So rkxtech have a repair kit available like Wolvez stated.

https://www.rkxtech.com/collections/vac ... m-pump-kit


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## 66yyhhnn66 (Jul 23, 2018)

I've fixed mine a few weeks back with removing the old gasket and applying a silicone instant gasket maker in it's place.

Seems good so far - no leaks anymore.


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## Hadaak (Dec 25, 2008)

Hadaak said:


> For the record TT is 97500 KM old.
> We'll see how many KM the patching I did will hold.


Just for the fun of it I'm updating this thread again. RTV is still holding at 181.000 km


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