# DSG Fluid Leaking After DIY Change?



## notamechanic (Oct 26, 2012)

Hey guys, 

I have a 2010 VW CC with the 2.0T TSI engine and the DSG transmission. 

I did the DSG fluid change at 40,000 miles as specified by VAG. New fluid, filter, o-ring for the filter cap. Around 7,000 miles later, it began leaking from the filter cap. 

So I changed the fluid again. Again, 8,000 miles after the fluid change it is leaking from the filter cap again. I made sure on the second change that the filter cap threads were clean of any debris and made sure it was on stout. Pulled the battery out to tighten up the filter cap and it was on securely, but I was able to snug it up a little further. 

Anyone aware of what I might be doing wrong. I have no idea on how much fluid I may have lost, but driving it this way but it doesn't seem to have any issues shifting. How should I refill to make sure I have the correct amount of fluid in the trans without draining everything and refilling AGAIN?


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## DasCC (Feb 24, 2009)

did you allow excess to drain out after getting the fluid up to temp?


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## strayts (Aug 12, 2013)

DasCC said:


> did you allow excess to drain out after getting the fluid up to temp?


 +1. 

I'm hoping to tackle this in another 2.5k miles or so, and I want to learn every possible mistake that could be made. OP, did you drain the excess?


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## DasCC (Feb 24, 2009)

strayts said:


> +1.
> 
> I'm hoping to tackle this in another 2.5k miles or so, and I want to learn every possible mistake that could be made. OP, did you drain the excess?


 There is a great write up for this on another forum. The guy even made it a PDF. You'll need VCDS to check fluid temp.


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## DasCC (Feb 24, 2009)

http://forums.tdiclub.com/showthread.php?t=169356


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## notamechanic (Oct 26, 2012)

DasCC said:


> did you allow excess to drain out after getting the fluid up to temp?


I did the top fill method. I don't have VAG-COM.


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## DasCC (Feb 24, 2009)

notamechanic said:


> I did the top fill method. I don't have VAG-COM.


The leaking then probably from it being overfilled. You need to let the fluid get up to temp and let the excess drain from the bottom. The pressure is forcing it out of the filter cap.


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## notamechanic (Oct 26, 2012)

DasCC said:


> The leaking then probably from it being overfilled. You need to let the fluid get up to temp and let the excess drain from the bottom. The pressure is forcing it out of the filter cap.


Makes a great deal of sense, but I only put 4.5 liters in the trans when I did the fill. 

I suppose anything is possible, but is it likely that it is leaking because I overtightened the filter cap? I know that the cap isn't cracked though.


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## texbaz (Jan 10, 2011)

Interesting. Just double check make sure the o ring for the filter housing is not shoved all the way up against the filter housing flange and is sitting in the specific groove just under the flange. If you did the top fill measure what came and put back in what came out it should not leak . Check the O ring


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## notamechanic (Oct 26, 2012)

Okay, so I talked to a buddy of mine who is a VW tech. He thinks that I may have tightened the cap too much, pinching the o-ring.

Pulled the filter cap off, o-ring looks fine. Spun the filter cap back on by hand after cleaning the threads on the transmission and the filter cap. Then torqued to 15 ft. lbs. using a torque wrench. Checked it today after driving it for two days and oil is still collecting around the filter cap.


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## notamechanic (Oct 26, 2012)

Just to elaborate, this is the procedure I used.



Remove filter cap
Remove filter
Remove metal drain plug
Remove plastic snorkel
Replace plastic snorkel
Replace metal drain plug with new crush washer
Pour 4.5L of DSG fluid in
Install new filter
Install filter cap with new o-ring


I did *not* let any fluid drain after pouring the new fluid in, because I do not have a VAG-COM to measure the fluid temperature and I thought the transmission is supposed to hold exactly 4.5L...and I know I poured exactly 4.5L in. However, perhaps it is possible I overfilled it?

If you pour exactly 4.5L of new fluid in, does it still drip some out if you use the VAG-COM method of checking the fluid temperature?


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## DasCC (Feb 24, 2009)

Tough to say. Depends on how much fluid may have stayed in the trans when you drained it. 


Sent from my iDevice using Tapatalk


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## Allyn (Dec 23, 2001)

Anything further on this? I'm seeing the same, and have followed the same as the OP so far.

I'm good on level, but wanted to chime in on a fact - if overfilled, fluid will leak from the vent way before it leaks from the oil filter cap. The oil filter cap is supposed to form a complete seal.


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## SnoopisTDI (Jan 8, 2005)

If he over-filled it, why would it take 7k miles to start leaking? 

I think I'm in the same boat - changed it about 6k miles ago, and now it appears I have a small leak. I haven't actually had a chance to find the source, but I'm pretty sure it's DSG fluid. Are there any "common" leak spots?

I'll probably warm it up, pull the plug to see if I anything comes out (doubt it), and then add 250mL and repeat.


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## Yareka (Mar 5, 2002)

For those that have leaking around the filter housing, did you use the vaico filter or the OEM?
Have seen the Vaico filter/oring combo leaking on a few cars. Swapped out for the OEM filter/oring combo on those vehicles and have had no more issues.


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## Allyn (Dec 23, 2001)

Some of these filters are coming with thinner o-rings. If you see a leak, chances are that's the cause. The o-ring should be thick enough to pass 2-3mm past level with the plastic housing groove. I'd say just keep the factory o-ring on there unless you get a replacement from VW. Don't trust the ones coming in the kits.


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## SnoopisTDI (Jan 8, 2005)

I checked mine last weekend and the o-ring that came out was flat, almost like a rubber band. I don't know if that was from being squeezed in place or if it was a bad o-ring. I know the oil filter o-ring on my TDI never came out flat like that. 

Replaced the o-ring and filter, cleaned up the oil that had pooled around the filter housing, and I think it's all good now. 


Small side note, though: after checking the level and replacing the drain plug, I noticed I had dropped the washer. I shut the car off, and removed the drain plug thinking I could put the washer back on and replace the drain plug without changing the fluid level... wrong move. Apparently, if the car is not running, you lose more fluid. Or at least that's what it seemed like. I lost more in those few seconds than when I drained the excess while running .


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## RD-GLIDER (Jun 10, 2013)

Looks like I'm going in to replace the o ring. Starting leaking last week and has been 7-8k since service. Was able to reach in and give it a little turn however that didn't stop the drip.


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## jhboult (Feb 7, 2011)

I have a similar problem on the wife's 2009 Jetta TDI/DSG. Car has 74k miles on it, and we did the service at the 40k mark. Out of the blue, it started leaking, and it looks like it is from the filter cap. 
This car has been 100% bulletproof, and this is the first issue. (all maint done on schedule, etc.). 

My question is. What is the part # of the Filter Cap? If it is around $30, i may get a new cap (i hear they can warp slightly) and a new O-ring. It barely leaked as far as i know (pooled on splash guard and dripped slightly in garage). 

So i may pour in a half a liter, replace the items above, and wait until 80k to do a full service at my Indie. He charges about $400, so i won't want to do it too prematurely. 

thoughts? Part #'s?


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## notamechanic (Oct 26, 2012)

jhboult said:


> I have a similar problem on the wife's 2009 Jetta TDI/DSG. Car has 74k miles on it, and we did the service at the 40k mark. Out of the blue, it started leaking, and it looks like it is from the filter cap.
> This car has been 100% bulletproof, and this is the first issue. (all maint done on schedule, etc.).
> 
> My question is. What is the part # of the Filter Cap? If it is around $30, i may get a new cap (i hear they can warp slightly) and a new O-ring. It barely leaked as far as i know (pooled on splash guard and dripped slightly in garage).
> ...


Purchase a new cap (comes with o-ring) and add fluid, pull metal drain plug and any excess will drip out. That is all there is to it.

Not sure what the part number is, I'm at work. Hopefully someone can chip in on that.


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## jhboult (Feb 7, 2011)

That's what i was thinking. Not ideal, and not exact (i know the DSG is picky about fluid level), but should be fine for another 5-6k miles. 

My indie shop said he has seen a lot of warping/cracked housings and has had really good luck with these. http://www.uspmotorsports.com/DSG-Cool-Flow-Aluminum-Filter-Housing.html

Might be worth the extra cash . It is really odd that i can't find the part # for the OEM plastic housing.


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## UNFORGIVABLE (Oct 20, 2012)

did you lube up your o-ring


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## georgy (Nov 14, 2010)

Just curious...how much (will any?) oil will come out of the filter housing if I open it to replace the o-ring without draining any oil?

I seem to have a leak coming out of the filter housing as well on my 2011 GTI.


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## georgy (Nov 14, 2010)

Well it seems only the oil within the housing...
My leak seems to have stopped after replacing both the housing and the o ring. I had lost about 250 ml of fluid.

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## mfractal (May 16, 2005)

same problem... vaico filter and o-ring.

replaced the Oil about 5kkm ago, let the excess drain as required. problem is i have no idea how much of it has leaked so will have to do the whole oil change procedure all over =////

major pita.

Anyway, ordered the USP cool flow filter + housing and OEM o-ring (it comes without it).

Part number is : N91084501 if anyone needs


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## S WORD (Jul 21, 2011)

Just had same issue. Had DSG serviced back in Dec. All was fine. Then when doing oil change noticed a wetness on DSG. Noticed fluid on top. Found out that the o ring was flat. Replaced the filter housing and oring with a new set and problems solved.


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## S4BiT (Mar 11, 2014)

Found out the same problem with my car today, dripping oil from the filter housing  Not shure how long it was like that so there can be some oil missing from the gearbox, hope its not fcked up something in there. Try to get it sorted tomorrow or friday with the new o-ring, do i have to put the new housing for shure?


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## Ed52 (May 21, 2001)

S4BiT said:


> Found out the same problem with my car today, dripping oil from the filter housing  Not shure how long it was like that so there can be some oil missing from the gearbox, hope its not fcked up something in there. Try to get it sorted tomorrow or friday with the new o-ring, do i have to put the new housing for shure?


Replacing an O ring in a day or two - leak from filter.


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## Ed52 (May 21, 2001)

Ed52 said:


> Replacing an O ring in a day or two - leak from filter.


Replaced the O ring. The filter housing cap leak was due to a flattened O, actually D ring.


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## S4BiT (Mar 11, 2014)

Ed52 said:


> Replaced the O ring. The filter housing cap leak was due to a flattened O, actually D ring.


Exactly like mine was, flattened O ring, now theres no leaks. While i was there i put the new filter in also and corrected the oil level.


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## motoracer47 (Jul 3, 2012)

I have not tried it myself, but I found a setting in: VCDS\transmission controller--- for fluid level check. No idea if its meant for the DSG or not, but thought I would throw that up. Might be a way for people who have had a little fluid leak out to figure out how much they need to put in. Then again, it might have nothing to do with the DSG, and is therefore useless info. 


I will say I think we can sum up this problem as this:

The leaking is caused by non factory O-rings for the filter housing cap. If you are not confident that the o-ring you got with your filter is the factory one, inspect the old o-ring, make sure there are no tears or rips, and re-use it. MAKE SURE TO LUBRICATE THE O-RING!!!!!!!! Probably would not hurt to dip your finger in DSG fluid, and smear a thin layer of fluid on the filter housing itself where the o-ring will make contact.


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## notamechanic (Oct 26, 2012)

Just wanted to touch base on this thread after putting another 40k miles on the car after resolving this issue.

Now at 97k miles, I have had no issues with the transmission. This is despite it leaking unknown volumes of fluid over the period of time it was leaking. I find no reason to worry about any damage to the transmission in the event of a slight leak. Just resolve the problem when necessary.



motoracer47 said:


> The leaking is caused by non factory O-rings for the filter housing cap. If you are not confident that the o-ring you got with your filter is the factory one, inspect the old o-ring, make sure there are no tears or rips, and re-use it. MAKE SURE TO LUBRICATE THE O-RING!!!!!!!! Probably would not hurt to dip your finger in DSG fluid, and smear a thin layer of fluid on the filter housing itself where the o-ring will make contact.


I completely agree. If you are concerned about the new o-ring sealing properly, you should have no issues using the old one.


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## Ed52 (May 21, 2001)

If the O ring external sealing surface is still round, not flattened I would reuse it. 



leaky flattened O ring left, new right.


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