# Vacuum leak found!



## CincyJSW (Jul 10, 2018)

Can somebody help me with this semi rigid plastic hose number? It’s located behind the n75 valve and mine is super rigid and brittle and has a nice crack in it that I taped up a bit and now you can really hear that hiiisssssssssssing leak. If I’m being thorough, I should also replace that little check valve and the rubber hose above the check valve. Any help is much appreciated, please drop some knowledge on me!





























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## QCOUPETT (Dec 21, 2012)

CincyJSW said:


> Can somebody help me with this semi rigid plastic hose number? It’s located behind the n75 valve and mine is super rigid and brittle and has a nice crack in it that I taped up a bit and now you can really hear that hiiisssssssssssing leak. If I’m being thorough, I should also replace that little check valve and the rubber hose above the check valve. Any help is much appreciated, please drop some knowledge on me!
> 
> 
> 
> ...


This might help you with the part #:

https://parts.audiusa.com/Audi__TT.html

Good luck!


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## CincyJSW (Jul 10, 2018)

QCOUPETT said:


> This might help you with the part #:
> 
> https://parts.audiusa.com/Audi__TT.html
> 
> Good luck!


Shoot - not having luck navigating on mobile. Found a few diagrams that seem to show that line but don’t label it! Also seem to all be regular vw/Audi 1.8T and not the transverse that’s in the TT so it isn’t really helping. It’d be that “number 8” check valve and the lines on both sides of it I think, but again, they’d be different in the TT, right? 










Hmmmm, now found a post about what appears like that line and it might be a broken brake booster line?! Oops! WHAT ARE THOSE PART NUMBERS PLEASE?! Brake booster lines and check valve! 

https://forums.vwvortex.com/showthread.php?4719133-Cracked-Brake-booster-line




















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## asiwa (Dec 18, 2014)

All I did was put in the criteria for a MKI TT with the 180 motor on ECS and searched "brake booster":

https://www.ecstuning.com/b-kayser-parts/brake-booster-vacuum-pipe/1j0612041gq~kay/

Granted I am not nearly as familiar with the 180 as I am the 225, but based on your pictures that appears to be the correct part. If not you should be able to find what you need with some additional searching.

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## CincyJSW (Jul 10, 2018)

asiwa said:


> All I did was put in the criteria for a MKI TT with the 180 motor on ECS and searched "brake booster":
> 
> https://www.ecstuning.com/b-kayser-parts/brake-booster-vacuum-pipe/1j0612041gq~kay/
> 
> ...


Literally just got in an order from ECS - should’ve probably just asked them straight away. I searched that part and found a thread of a guy who bought that part to fix my same problem but couldn’t get it to fit? Linked here - https://www.audiworld.com/forums/tt-mk1-discussion-9/part-number-help-please-2905873/ 


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## asiwa (Dec 18, 2014)

CincyJSW said:


> Literally just got in an order from ECS - should’ve probably just asked them straight away. I searched that part and found a thread of a guy who bought that part to fix my same problem but couldn’t get it to fit? Linked here - https://www.audiworld.com/forums/tt-mk1-discussion-9/part-number-help-please-2905873/
> 
> 
> Sent from my iPhone using Tapatalk


He has an AMU motor. My guess is that he purchased the wrong part for his engine code. The AMU (225) has different lines from the 180 in some places. 

If you search for brake booster line under your car on ECS you'll get a whole host of results, many of which specify a year/VIN range and engine code. If you match them up you shouldn't have a problem.

Edit: I could be incorrect, as the brake booster line specifically appears to be the same between all TT models. The part I linked is the only one that really matches.


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## CincyJSW (Jul 10, 2018)

Was able to remove and attempt to bandaid it enough that the engine wouldn’t run rough, but man, when that brake booster line leaks the engine gets unhappy. After a good cleaning found part number for the line to be 1J0612041DS.










In trying to find whether this line is the essentially the damn part as the part number previously suggested (1J0612041GQ), I have found zilch. Anybody have any info? Thanks! 


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## asiwa (Dec 18, 2014)

Does this look like the part you're replacing?

https://www.pelicanparts.com/More_I...S-VAG&SVSVSI=&catalog_description=VACUUM PIPE

That's the only website I could find with a picture. The GQ part does not appear to be a revision of the DS part, so they are unrelated. A picture comparison confirms that; the GQ line is much longer and has several bends.

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## CincyJSW (Jul 10, 2018)

asiwa said:


> Does this look like the part you're replacing?
> 
> https://www.pelicanparts.com/More_I...S-VAG&SVSVSI=&catalog_description=VACUUM PIPE
> 
> ...


Thanks!! Hmmm the top part from the brake booster connection to the check valve looks about right, but the other side is too short and not the right connection. I’ve sort of traced the shape in blue and highlighted connectors in red in the attached photo. There’s a triple connect at the front end (so the single line joiner in the DS pic from Pelican doesn’t make sense), a straight run of about 18” followed by a nice 90 degree upturn into a check valve, followed by a half moon sort of hook (that does clip into a little body mounted plastic retention hook on the firewall) that has a nipple that connects to the front of the brake booster.











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## CincyJSW (Jul 10, 2018)

Went ahead and just ordered part no. 1J0612041GQ from ECS and will report back. Super common issue it appears but people just don’t finish out their threads and explain/show what they did! Frustrating to be sure. 

I’ll show old vs new and install DIY notes when it arrives in another week or so. AutoX helmet just arrived! 











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## MCPaudiTT (Nov 26, 2006)

For a better temporary fix, wipe it down (and the split) with alcohol (clear, any flavor, or rubbing). Let that dry. Put a THIN layer of caulk on the faces of the split, and a thin layer on top. Let that cure. Then tight stretch electrical tape over the top.


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## CincyJSW (Jul 10, 2018)

MCPaudiTT said:


> For a better temporary fix, wipe it down (and the split) with alcohol (clear, any flavor, or rubbing). Let that dry. Put a THIN layer of caulk on the faces of the split, and a thin layer on top. Let that cure. Then tight stretch electrical tape over the top.


Good for a quick fix, but as the leak directly affects braking ability and engine stability, going to have to remove and replace but thanks for the tip!


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## CincyJSW (Jul 10, 2018)

Replacement wasn’t too hard, getting the nipple into the brake booster was the hardest part. Weird that the part numbers didn’t line up, but the parts were absolutely the same - I couldn’t get a straight answer from VW about this, but who knows. No more boost leak, buttery smooth acceleration. Replaced the n75 and diverter valve before I found the absurd cracks all over the brake booster line, but whatever, they were probably due. Brakes are noticeably less spongy as well now since replacing the brake booster line. If you’ve never checked yours, check it. 





























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