Aygo Mk 1 headlight holding water

[DavyBoy888]

As the title says,  my nearside headlight is holding water,  is there an easy way to solve this e.g. a blocked drain hole or something,  alternatively can I dismantle the unit and reseal it ?  Picking the brains of anyone who has had a similar problem.

Thanks in advance as always.

[flash22]

No not really, water is getting in somehow these are designed not to come apart - time for a replacement unit, drilling a hole at the lowest point may be a short term solution

[DavyBoy888]

Thanks Bob.  I'll pull it out and see if there's anything obvious... despite the warmer summer weather,  there's a fair old bit of water in there.  Unfortunately I don't smoke or vape - locating the hole would probably be the only useful purpose for those vices !  I suppose I could submerge it in a bath of water and see where the ingress is.

[flash22]

A syringe and a bit of tube to suck the water out, available at most chemists or fleabay

iirc it's a bumper off job to remove the headlight https://www.youtube.com/watch?v=_OaH_nMLK8k

 

[Stecha]

Is the headlight bulb rubber seal missing ? Big black thing, bet that's missing

 

[Derek.w]

I drill a small hole low down after removing light then when its dry you can seal across the top and down the edjes with any clear silicone sealant then refit it again.

[DavyBoy888]

14 hours ago, Stecha said:

Is the headlight bulb rubber seal missing ? Big black thing, bet that's missing

 

Are you talking about the rubber at 1:34 in this vid here ?  

 

[DavyBoy888]

@Derek.w Thanks for that... I'll give that a go.

[mrfixer]

Take the headlight out and remove the bung and the bulbs/holders.  Get the headlight bone dry (use a hairdryer, blowing air inside too).  Clean the lens-housing joint using something like brake cleaner.  Run a bead of clear exterior-grade silicone sealant around the join and let it harden before refitting the light into the car.

[Stecha]

1 hour ago, DavyBoy888 said:

Are you talking about the rubber at 1:34 in this vid here ?  

 

Yes, that's the one mate

[DavyBoy888]

OK... a follow up on this.

I took the bumper off,  removed the headlight and removed the bulbs etc....

First off the rubber bung is there and is intact... so it's not that.

There was a fair bit of water in there so I slowly rotated the headlight around with the water against the lens seam as I thought that may be a good way of locating where it was leaking.  No water emerged anywhere !  It would appear that the seam is water tight !

So I'm perplexed as to where the leak is.

For a change,  today is lovely and sunny so I got as much water as possible out by shaking the light and then left it cooking in the sunshine and it now seems to be dry inside.

 

Now one thing I'm confused about is the vent hole(s) or the lack of them.  My understanding is plastic headlights should have vent holes so that the temperature can be regulated - and moisture can escape.  But I can't locate them on the Aygo lights.   Anyone know where they are... or if they don't exist whether I should drill one ?

 

[flash22]

No vent holes in any modern headlight I've seen, years of condensation and no use of the headlights (heat from the bulbs drive off the moisture

[DavyBoy888]

Really ?  I've a Renault Clio and Ford Focus Mk2 and both have vent holes.  Unless the housing is vacuum sealed [i.e. like a double glazed window] moisture and condensation will get there and will need to be released in some way or other even if it's evaporated by the heat of the bulbs.

 

https://www.thevehiclelab.com/condensation-in-headlights/