Really annoying roof/boot leak on Mk7 ZS

[brownerboy96]

Hi guys, 

Firstly, sorry for asking a question which i know has repeatedly been asked before. I have tried all of the already made suggestions so making my own thread was the only way. 

I've got an infuriating leak on the rear right hand side of my 59 Zs. I've had it for a while and it gets more infuriating everytime I think i've fixed it, only to optimistically look in the boot after a rain shower and see a puddle in the spare wheel well again. 

So far I have:

-Had the bumper off and replaced any tape that was missing/damaged. 

-Had the rear light off multiple times and used enough sealant around it that I probably could have used to reseal half the windows on my house. 

-Put sealant around all the joins on the body joins above the rear right light cluster. 

- Water tested around the rear drivers side window incase it was coming in there

- Had the roof trim off, checked for any holes, cleaned the gulley, and replaced the tape. The tape that came off was a bit damp for the very most rear section, but not soaked, I thought that was just  down to where the water runs down the gulley, as there was no obvious cracks or holes on the metalwork.

I've done another test this morning, pouring the water directly above the central pillar behind the drivers door and observed. 

I've attached a photo of where the water was running down inside the body above the light. 

I will add that no water is inside the main cabin at all, seats are bone dry, floor is dry and the roof is dry with no sign of mould what so ever.

 

[Neb_engineer]

are you sure its not the gasket on the back of the rear light, i see you have put sealant on the top but did you check the actual gasket?

[brownerboy96]

4 hours ago, Neb_engineer said:

are you sure its not the gasket on the back of the rear light, i see you have put sealant on the top but did you check the actual gasket?

On inspection the gasket looked fine, the sealant goes the whole way round the light unit with a layer inside too. Judging by where the water is running down i think it’s coming in further up. 

[Eatonm112]

It will be the grommets from the boot lid to the car, just had a similar thing on my 15 plate.

Also with the rear lights I take them out every year or so and clean, wax then I put silicon grease on the seals before fixing them back in.

[Lenn1974]

I'm having exactly the same issue on my sons 2012 fiesta.  At the weekend, we removed the roof rails, applied sealant and new double sided tape.  Also applied more sealant around vent holes and rear boot grommets. Just waiting to see if the boot fills again.  I do know that if the boot fills enough and you do a bit of driving the water runs down in the rear footwells.  Also put extra sealant around the rear light rubber seals, means they will be more of a pain to remove it needed, but probably worth it.

[Nick_T]

Almost certainly coming in from under the roof gutter trims, I'm assuming the arrow is where the water is runnning in? 

 

On 4/10/2019 at 5:56 PM, Nick_T said:

Will be getting in underneath the black roof trims. Where the side panels and the roof panel meet it is covered with a bead of sealant from front to rear. Once the body shell is painted the black strip is attached over the top using double sided tape.

It's common on the early build Mk7 for this sealant to crack with age allowing water to seep in between the panels and run into the boot area. My car was affected by the same issue, if the water is clean then this is more than likely where your problem lies.

 

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