Fixing the leaky roof antenna

Car stuff Apr 15, 2021

It took me way too long to figure this one out, but finally, the water leak has been found.
It was the roof antenna gasket - or rather, the gasket being absence.  

This would cause a very moist interior, electronics would go haywire (doors not locking/unlocking, windows would work sporadic) and mold would develop in the car.

Overall, not very nice. It's very easy to spot if the Polo is moist or not on the inside:

Moist spots are white, and marked with a yellow border

As a temporary fix I put some acid free petroleum jelly around the seals - the same I've used on the gaskets for both rear lights last year.

Before and after the petroleum jelly got applied:

The roof antenna, with a missing gasket
The roof antenna, with a temporary waterproof seal

Of course, this is not a long term fix. As soon as the temperature rises, the petroleum jelly starts to runs down from the roof antenna. And with that, the seal will become leaky again.
My older sister wanted to help me with this, and why not, let's do it together :>  

Sadly, I did not focus on making pictures that well this time. But the pictures I have will give a solid idea of what happened.

The roofantenna gasket repair kit, the gasket, an o-ring, and a new 22mm nut.

The roof antenna is fixated with a 22mm nut, which is quite hard to reach in a place full of untreated glass fibre - above the headliner.
For this you have to loosen three trim parts, as marked in the picture below.

Three cosmetic parts need to be taken off, first the red part, then the two yellow sides

With some fiddling, the nut got loose and the antenna popped out with no problem.

The roof antenna nut and the push on connector

This mess was what the petroleum jelly left behind:

The hole in the roof left behind without the roof antenna

The watery looking part is also petroleum jelly, which already started to run off.

Next, replacing the o-ring:

The roof antenna itself, with no gasked and a rather squished o-ring

My sister made sure the mating surfaces were nice and clean.  

The roof antenna with a new o-ring and some silicone grease

And putting everything back together, from the gasket itself I do not have pictures from when the antenna was detached from the car.
This was fairly straightforward, there's only one way it would fit on the roof antenna.  
The roof antenna automatically aligned itself with the roof, and the o-ring made a good seal.

It was not easy to get a good picture, but I think it looks pretty neat. 

Finally, we were done! :>


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