# How to: Plenum Access for Drain Inspection & Cleaning



## SwissJetPilot (Apr 27, 2014)

These instructions are for a LHD Mk2 TT so there may be some subtle differences with a RHD vehicle. In addition to drain access, you'll need to remove the Plenum if you want to access the following:

*• HVAC Intake
• ECU Module
• Wiper Motor & Assembly
• Front Shock Tower Bolts & Bearings
• Soundactor **









*Tools - *

• Wiper Arm Puller (Not mandatory but makes the job a lot easier)
• Blue low-tack painters masking tape
• 13mm socket
• Small Screw Driver
• T25 and T27 Torx
• Safety Glasses
• Air gun, canned air or a vacuum cleaner
• Your favorite surface cleaner and rubber treatment

*Procedure -*

1. Turn the ignition to the first position and use the DIS to set the wipers into the Service Position. Turn off the ignition and remove the key.
















2. With the wipers in the Service Position, use a length of blue painters tape about 1-foot long (30cm) to mark where each wiper is located. This way you can put them back at this exact same spot. The blue painters tape is less tacky and won't leave a residue on the glass when you remove it.

While the arms are off, inspect the wiper blades and replace them if they have become hard or cracked or show signs of obvious wear.

Driver Side 22" (550mm) Pinch Tab Flat Style Wiper Blade
Passenger Side 21" (530mm) Pinch Tab Flat Style Wiper Blade








3. Open the hood and use a very small screw driver to pry off the caps. Note the slot in the wiper arm. Use care that it doesn't pop out and go flying into the deep, dark depths of the engine bay, never to been seen again!
















4. While holding the arm in place with one hand, use the 13mm socket to remove the nuts. If either of the arms move out of the Service Position, see the note at the bottom of the post. *Note* - when installing, tighten the nuts to 17Nm.








5. With the nuts removed, carefully position the Wiper Arm Puller to remove the arms from the wiper shaft. As you tighten it, wiggle the arms a bit as this will help break them free. They may "pop" free as they come loose. Some come off easier than others. *Note* - The official wiper puller tool is VAG T10369-1. If you use a non-OEM tool like mine, be careful that the end of the screw sits on the center of the wiper shaft. If it slips off while being tightened, it could damage the wiper shaft threads.








6. As you remove each wiper arm, use a piece of tape and a marker to identify the wiper; (e.g. driver vs. passenger).








7. Once both wiper arms are off, the Plenum can be removed. Start by unfastening the two T25 Torx screws.








8. Carefully lift up one side and release the leading edge rubber trim across the entire length of the Plenum. You don't have to pull it off completely, just roll the seal off the edge of the Plenum. Note the extra protrusion, this may be a specific LHD/RHD feature. Once the leading edge is free from the seal, pull gently and the the rear edge of the Plenum will come away from the windshield.

























*Inspection and Cleaning - *

9. There are actually two drain holes on each side of the Plenum area located just behind the shock towers; the large oval hole with the rubber drain valve, and a round 13mm hole right next to it. Both of these drain into the area behind the wheel well arch.

Inspect the drain valve for any leaves, twigs or other debris that may have accumulated. Check inside the drain valve as debris may have accumulated and not passed through which will continue to block it. Be aware that anything you push through might possible end up trapped behind the wheel well arch. If yours is particularly manky, it may be worth pulling the wheel arch to remove any debris that may be accumulating back there.

Fortunately my drains were clean since the car is garaged, but there was a nice layer of pollen and dust on everything. If you discover one of the drain valves is missing, it may have been shoved down into the opening and is currently caught behind the fender well cover.
















10. If the drain is really blocked, it can be removed, cleaned and re-installed.








11. Once the drains are clear, remove the HVAC intake cover and check for leaves or other debris that may have made their way into this area. You'll need to remove two T27 Torx screws. Inspect the foam seal along the top edge of the cover. Mine was starting to come loose, so I used a strip of window foam seal and replaced it. The OEM seal is about 13mm wide by 9mm high. I don't think it seals anything, it just prevents the cover from rattling against the metal work.
















12. Give everything a good clean, and apply a light coating of your favorite rubber treatment to all the rubber bits. I prefer either Sonax or Nigrin GummiPfleger as I use it on the door, trunk and convertible top seals. Put it all back together in the reverse of disassembly. Remove the tape from the windshield and turn off the DIS Wiper Service Position setting.








*Note* - If you happen to move the wiper arms or the wiper mechanism out of the Service Position at anytime during this procedure - don't panic! Be sure the engine bay is clear and close the hood - it has to be closed or the wiper motor won't operate. Turn the ignition to the first position. Turn off the DIS the Wiper Service Position setting. Then turn on the Wiper Service Position setting. Turn off the ignition. The wiper shafts will once again be in the correct position when you reinstall the wiper arms.

*Parts - *

In the event any of your parts are damaged or missing, here's some of the part numbers you may encounter -

1. Access Cover - 8J1 823 755
2. Drip Channel - 8J1 819 979
3. Side Seal - 8J0 823 721 (verify left or right)
4. Cowl Grille - 8J1 819 401








*Drain Valve - 8J0 805 271*









For additional information on the wiper system, refer to the Work Shop Manual -

*FAQ - Audi TT (8J) Workshop Manuals & Self Study Programs
Electrical System - RG 27 90 93 94 96 97 - A005TT01320*
https://www.ttforum.co.uk/forum/viewtop ... &t=1833829

* For more information on the *Soundactor*, follow this *link*.


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## CharlieS (Jan 5, 2018)

Excellent guide..cheers Swiss!


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## motornoter (Jul 16, 2012)

Nice one SJP - where did you get the puller from to remove the wiper arms?? Some I'v looked at are a bit bulky and look like they wouldn't clear the bulkhead....


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## Graham'sTT (Dec 6, 2014)

Yes, good write up SJP. May be tempted one day...

For information, wiper service position can also be achieved by:
• Ignition on
• Ignition off
• Press wiper stalk downwards - wipers move to service position
• Ignition already off - I would remove key at this point.

When finished:
• Key in and turn ignition on
• Press wiper stalk downwards - wipers return to parked position
• Ignition off.

Easier than going via DIS. Discovered by accident, but some VW handbooks explain it this way and it has worked on both TTs I've had.


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## SwissJetPilot (Apr 27, 2014)

@ *motornoter* - I bought mine from Amazon. It's not exactly like the VAG T10369-1 tool, but close enough to get the job done and not nearly as expensive! 

@ *Graham'sTT* - Very clever! Good to know.


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## MT-V6 (Jan 11, 2015)

Good guide. Identical process for RHD cars though the parts are reversed


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