Introduction

Recently I discovered a lot of water in the trunk of my Seat Leon Mk3 / 5F (2014+) . After much investigation I saw drops falling in the grill on the left and right side.

As the joint between the sunroof and the car is not perfectly waterproof there is a system catching the water. The water collected there is then left out through 4 drains (2 front, 2 rear behind the back window). If those drains are blocked the water cannot leave and will go over the border and enter the car.

In my case I was lucky to have water in the trunk, so there's no damage in the inside/finishing.

The drains can be blocked at the entrance (roof) or a the exit of the tube. In my case the entrance was perfectly clean, but the exits were blocked.

This howto is to help you clean the exit from the front of the car, and the rear of the car.

  1. VrTbPt32ejMSx2bF
    VrTbPt32ejMSx2bF
    AwF56CSCd3GQ4KBy
    • Open the sunroof completely

    • Locate the sunroof drains, verify if there's no dirt inside at the entrance point. (aka: you can see the clean hole like the picture)

    • Poor water in the rail to test if it works.

    • Wait for the water to disappear. This should take a few seconds, not more. You should see the water come out at the bottom of the car next to the tire.

    • If the water remains it means the drain is blocked at the exit.

    • Do this over for the 4 corners of the roof. To test the back drains just poor water on the most rear part of the opening. You will see the water go below the back window and come out below the car.

    • If you put too much water you might see drops coming out from the vent in the trunk.

  2. qR2mKYTtZSXVdktI
    • Empty the trunk

    • Remove the spare tire

    • Remove the equipment

    • For your comfort remove the plug. Push it down and rotate.

  3. XyZtwfjNstJAdWIZ
    XyZtwfjNstJAdWIZ
    TWbTQyKPtGSnJxPv
    BIVMGZrNRrdRUFyr
    • on the left side pull up the vertical plastic

    • unclip the 3 plastic "caps" in the back

    • do the same thing for the right side of the trunk

  4. D5ZhOByU3RDnWpEB
    D5ZhOByU3RDnWpEB
    GSKQFkrpqQ5YqGfg
    • now we need to take out the middle piece, as this holds the sides in place

    • unscrew the 3 torx screws from the inside of the trunk

    • once unscrewed, pull up the plastic thing from one side, you will hear clips coming loose (sounds like something breaks)

    • pull gently on the other side

    • take the big piece completely out of the trunk

  5. UCTFunRWhFsGIkHU
    UCTFunRWhFsGIkHU
    laannrxb42PPqSLJ
    WChqdZoNBQcK1JQZ
    • Now we're going to take out the top plastic thing

    • Unscrew the 2 torx screws on the left. The back screw is smaller than the one hidden behind the seat handle

    • Pull gently in the bottom side of the plastic. Then gently on the top side. Wiggle a bit. You should hear a sound of the pins coming loose. If you pull too hard you might break one of the plastic pins. (if you break one it's not a disaster)

    • there is no need to completely pull it out, just pull it so that the bottom grey soft "wall" comes loose

  6. u2NYgLDaXUqSUQxs
    u2NYgLDaXUqSUQxs
    LAu42EvLMNhhUrV2
    uZYkxldb5jpLYyjd
    • Pull the grey soft side towards you and you should see the water drain behind

    • Do NOT pull the tube now

    • Pull the black end out of the bottom. Leave the tube attached.

    • Once out, you should see the full plug.

  7. BNCBvfMXscoAfUvq
    • Notice how dirty and clogged the drain is.

    • Unplug the drain from the tube, take care not to pull on the other side of the tube as you don't want it to be detached on the other side

    • Once you have the black end in your hands, clean it inside.

    • Once clean, FIRST put the black end back in the hole of the car

    • Afterwards push the tube in the black end so it fits back together

    Good point about not pulling on the tube. In my case the tube had become detached at the top, it is just a short push fit and had become detached during use. Relatively easy to get at. remove the white side pillar cover which is held in place with 1 screw and 3 clips, then carefully pull the headlining down. this gives access to the top connection.

    Dave Creasy -

  8. QDnYDDW2cUyZP1Jy
    QDnYDDW2cUyZP1Jy
    R3cxqsugZ22oxHRX
    • Follow the steps backwards.

    • When closing the left big plastic, and BEFORE putting the screws, keep in mind the joint on the back. The joint needs to be put back above the plastic. It's easy if you start at one end and gently slide it above the plastic using your fingers. Do not use anything that cuts.

    • Same story for the big middle piece, FIRST the joint, THEN the screws

  9. WAaB6bKBDQIBSEFO
    WAaB6bKBDQIBSEFO
    6wUgmN5Q1isRcH3c
    qVWNZkGVNXTTbrCr
    • Open the hood of the car

    • On the outer left and outer right you can see a foam. Gently take it out. Take care not to break the fragile end. This will reveal a plug.

    • Take a plier and gently pull the plug out

    • Take the pin out of the plug. This is needed when we will re-assemble everything. Later, at re-assembly we'll first put the plug, and then the pin.

  10. aZAlZVSFAmlJ3Mg5
    aZAlZVSFAmlJ3Mg5
    bsjNb5XginWWolia
    • Remove the 3 clips

    • You can do this easily with your hand. Hold on tight and pull/slide them out. Make sure they don't fall in the motor.

  11. 5QZYKKiTuU4ParQO
    5QZYKKiTuU4ParQO
    jEjjNYeAKYc6RHt2
    AQevwk5JIqpWjUV4
    • Raise the plastic grid and see what's below. While I did not manage to take the plastic out, it naturally came loose a bit later. You can force if to come loose by pulling it UPWARDS on the side of the WINDOW.

    • On the left side you will see two screws (10mm) holding a covering plastic. This is meant to prevent water to come in the air-intake.

    • If you gently lift the plastic up and unscrew those two bolts. Make sure you DO NOT DROP THEM.

    • To remove this plastic, push the left (big) side (towards the car). The right (small) side will come loose and you can pull the whole thing out by taking the right (small) side out first.

  12. dt4XmjepnMxWZCVm
    • Still on the left side of the car, raise the plastic grid again and you'll see our water drain exit valve.

    • To clean it you can squeeze it with the hand, put your finger in it.

    • Once cleaned, poor some water in the open roof to force some water to come out and continue the cleaning.

    • On the right side of the car you will find the drain well hidden behind the mechanic of the windscreen wiper.

  13. UcdVcIBEhkkNpKvL
    • Follow all the steps in reverse and you're done.

    • If, like with me, the plastic grid came loose on the windscreen side you will need to push it back to its place over the whole windscreen. Press firmly on the border of the plastic / windscreen to force it in place.

    • Poor some more water in the drains in the roof and you're done !

    Good evening I saw your tutorial on disassembling the front of the plastic grille ... I wanted to know how to disassemble the cable on the right that goes through the plastic panel

    Luciano De Cataldo -

Conclusion

Poor some more water in the roof drain and enjoy how everything drains away quickly !

Christophe Vandeplas

Member since: 13/07/18

377 Reputation

10 comments

Thanks for this guide. It saved me a lot of time troubleshooting the pool of water in my spare wheel well.

I did find an easier way to clean the exit plugs of the rear drains. You can get to them from under the car without disassembling anything. The left one is in plain sight (and reach). The right one is hidden behind a metal sheet but there are holes in it so you can still clean the plug with a long tool.

Albert Einstein -

I have removed the red “valve flaps” at the end of the drain to allow for continuous flow and no buildup of debris. Naturall, those flaps are there via some designers calculations, however I Cannot fathom the reason. Scared of ants climbing up the tube ? Having fun seeing how much water can the tube safely hold before releasing ? I just dont know. If someone has a good idea why these flaps are there, let me know. Obviously, the tension holding the flaps closed is too strong. Anyway, my drains are now free of sludge and free flowing. 2018 VW Alltrack

Studio POP -

Thanks! This is a very good manual! It worked for me! My Seat Leon ST 2019 had some water where the spare wheel is based. It looked like a smaal pool. Also the backseat was soaked. I also removed those red ‘valve flaps’ at the end of the drain. Maybe it prevents that spiders go inside? For cleaning the front drains I used a small iron cable ant put some plastic on top of it just to prevent to poke holes in the hose. Hopefully the leakage is know gone!

Michiel van Rooijen -

Discovered a leak into the boot of our Seat Ateca so took to google for ideas when I came across your instruction. Going to see if this is the culprit as soon as possible. Thanks for sharing.

Meta Rich -

Many thanks for this post…. Sorted my issue with these brilliant instructions. Had to bail out about 30 litres of water from where the spare wheel is… and this has provided the fix!!! Many thanks!!!

james shapland -

This is a brilliant guide. Really helpful and well put together. Helped me out with this very problem. Thank you!

James Wagstaff -

Lot of thx!! Saved me a lot of money and it's fun to know my car better. I will remove the red valve's also for a continuous flow and the tip of some sort of cable to clean the front hose is very handy too

Ferdi -

Had water coming from left side into the spare wheel well. Like the first commenter, I ended up not dismantling anything, since particularly the back left drain is very easy to clean from underneath the car. Turns out, thick grease from the sunroof mechanism (they had used it very liberally in the last service) had clogged the drain.

A. Peteri -

Best instruction ever! Thank you so much, this saved me a lot of money because i could fix it by myself! Step by step and easy.

Daniel B. -

This is an excellent guide, i had done this before I read this, there's actually a service bulletin from seat about this issue, i removed those red caps too, i don't see the point in them the tubes were blocked with about an inch of muck, i need to check the front tubes next.

neil rapsey -