Audi A4 Cab Rear Lights Water Ingress

[Mario T]

Hi All,

Another problem to solve. After many days of rain and dampness outside I've noticed that NSR light has water beads internally. Clearly, there is water getting and I wondered if anybody had a fix for this.? I removed the light recently, cut an old innertube into large washers, and replaced the light bulbs. TBF if anything it's got worse......  I did run a bead of mastic around the outer groove of the lens but I suspect it hasn't set very well due to the weather. Is there any goto trick that anybody has out there or am I chasing shadows with this attempted fix.

 

As always your help is greatly appreciated. 

[Magnet]

Hello Mario,

It’s possible that adding a bead of mastic has made things worse since you’ve probably now ‘locked in’ the condensation. 
Kind regards,

Gareth. 

[Mario T]

Hi Magnet, it's a good point. I will remove and dry out this week. Is there any known water ingress areas on this cluster type.?

 

Thanks

 

 

 

 

[Magnet]

Hello Mario,

It’s not uncommon to have condensation within light units. You could try removing your ‘mastic’ and thoroughly drying out the unit with a hair drier, before carefully resealing it with a good quality sealant. 
Kind regards,

Gareth. 

[Mario T]

Yeah I think that's a job for this weekend. I'll buy some good mastic and spend a morning getting it right. I just can't see where water would be getting in.

[Mario T]

I'm almost ready to give up..... I've sealed the edges of the light 3 times have taken my time. After the recent heavy rain the water is back. I'm at a loss it can't be my sealing as I really took my time.

What am I missing is it getting in the bulb holders. Does anybody have any experience please.?

Is there another area I need to look at.? I did my Skoda ones and gave them no where near the same care and they've been fine.

 

If not where is the cheapest to get new ones although I'm not ready to give in quite yet.

 

Many Thanks 

Again

 

Mario

[Mario T]

Right ok - touchwood I've fixed it. Hopefully this may help somebody else.

I wasn't prepared to give up and so removed the light again. This time I really looked closely at the seals and was convinced the lense was sealed to the bulb unit. So after further inspection on the rear of the unit I noted some tiny hair line fractures almost went unnoticed. The rear plastic moulding of the light must get brittle. It wasn't just in one place. So I glue gunned all the cracks 3 in total and touchwood the lamp after some reasonable rain hasn't beaded on the inside.

 

Thanks Maz

[Steve Q]

Could water be getting in where the roof and boot meet? Isn't there a seal there that could fail?