C5 Mk1 WARNING -Removing rear view mirror cracked windscreen

[aspire_helen]

Argh!! To cut to the chase, as I attempted to pull the internal rear view mirror housing from its windscreen mounting, a crack approx 40cm long appeared horizontally under the mounting point (photo) ! And I wasn't even trying too hard, and its was my 3rd attempt! Haynes says "pull down sharply"....to release the housing from its (strong) spring clip.
The crack appears to have originated around the attachment point, and travelled in both directions, but I cannot detect a seed stone-chip. Just unlucky I guess. The housing is still stuck there, and I will not try again as the crack is sure to grow before it comes off. I will leave that to the windscreen replacement people.....£75 excess!! I have a spare mirror housing (photo) and it may be advisable not to simply pull it off but to gradually encourage the spring away from its mounting by forcing a wedge or spatula (wood) between the glass and housing and levering it off gently. I will watch how the fitter does it!

So why was I doing this? To access the rain sensor. Lexia3 was unable to establish dialogue during the global test with the "rain sensor/brightness ECU". Looking at the sensor, it looks poorly mounted to the glass. The windscreen was replaced a few years ago and I trusted the fitter to do it all properly. Indeed, the automatic wipers do operate in the rain and also when tested today with water splashes. However, the windows no longer close when it rains, when locked, as they did and should. I have 2nd hand rain and solar sensors so I thought I would connect those.

Grrrrr!

[Hell Razor5543]

When I replaced the mirror on my first C5 (with a 'reactive' mirror) I just slid the mirror DOWN the windscreen, rather than pulling it AWAY from the windscreen. I wonder if Haynes could have phrased it better?

[myglaren]

When I replaced the mirror on my first C5 (with a 'reactive' mirror) I just slid the mirror DOWN the windscreen, rather than pulling it AWAY from the windscreen. I wonder if Haynes could have phrased it better?

Yep, same here.

[GiveMeABreak]

A word of caution here.

Once the sensor gel pad becomes opaque, that's it basically. You will start to get problems with the wipers on automatic mode and it may also affect the light sensor too.

Each time I have had C5 windscreens replaced I insisted the rain sensor was replaced too - after the last attempt on my C5 X7 resulted in poor operation. The fitters tried the old water over the wiper trick - but I wasn't having any of it, explaining that on my vehicle there were about 19 wiper speeds in automatic mode and that chucking a load of water over the screen is not going to show that it is working with light rain.

After proving the point when I grabbed his water gun and lightly sprayed over the windscreen and nothing happened he gave in and I had already taken a photograph before the replacement windscreen showing how clear the sensor was. It was clear to see that the sensor was now partly opaque.

I demanded a new one on their insurance at a cost of over £240 for the sensor and provided the correct part number too. He then came up and fitted it under my supervision and all was well.

So my advice is, don't let them get away with it if there is any opaque or milky appearance on the sensor - insist it is replaced. They have insurance to cover this sort of thing.

[aspire_helen]

The Haynes wording (page 11.14) is "Grasp the mirror base/sensor cover and slide it sharply downwards (see illustration)". The photo is of little use because it shows the base already separated. I agree a better wording would be "....slide the base downwards along the windscreen". As the screen is raked back at 30degs?? "downwards" as in vertically downwards is pulling the base more away from the glass NOT down it. I should claim!!

Marc Re the rain sensor, it already looks pretty naff and far from evenly fitted from last time, so I am confused how I could demand Autoglass provide or pay for a new one with the replacement screen????

[GiveMeABreak]

Ok, so your issue now will be that the naff sensor is as a result of the last fitting. If I'm correct, the glass fitters more recently tend to take photos of the windscreen and areas of the car to cover themselves in case of later claims of damage. This being the case, they may well take a picture of the sensor so it can be referred to later if a claim is made against them for a sensor replacement.

In my case my sensors were in perfect condition and I also had my own photographic evidence to I could show them that the sensor was now opaque in parts of the gel pad after they had detached and reattached the sensor - as this can destroy the adhesion leaving the opaque marks - much like reusing sellotape when it has fingerprints on it.

In this scenario you may not be able to make a claim especially if it was some time ago since the windscreen was replaced.

All is not lost though, as there are 'Gel Kits' that you can buy that contain the solution and syringes to re-make the silicone pad. These are quite cheap. An example here:

https://www.amazon.co.uk/Windscreen-Sen ... 4726&psc=1

Or you can buy the complete replacement pad for about £9 that goes on top of the sensor, like this if that's too much of a faff:

https://www.ebay.co.uk/itm/233585528636 ... olid=10050

[aspire_helen]

Thanks Marc. Re gel pads. I had seen the silicone pads on Ebay. They are none-adhesive - instructions say to wet the pad presumably to form a vacuum. However, a reviewer gave it 1* as it did not stick. SensorTack also make silicone pads sold by pma-tools - they have "how to use" videos on pma-tools website.
I have also seen Marcy pads -code RSP15 for C5 Mk1 (27mm) - which are self-adhesive flexible acrylic....also about £10 delivered.
https://www.gpat.co.uk/?i=Search+Results&s=rsp15
https://eshop.pma-tools.com/en/C5-01-08 ... icone.html

I plan to see what the fitter will use next tuesday and will probably ask him not to fit the sensor or mirror so I can explore why Lexia global test returns "no dialogue with rains sensor/brightness ECU". I did not think the sensors would have a separate ECU somewhere.

[GiveMeABreak]

It’s built into the sensor itself

[aspire_helen]

Just a catch up. The technician did not use a pre-formed gel pad. He removed the existing rain sensor and formed a liquid gel ring on the sensor itself, and let it set a while before fitting it to the new screen. The resulting sealing ring is far better than the one he removed.

[GiveMeABreak]

Nice One.