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Third brake light replacement DIY

163454 Views 99 Replies 53 Participants Last post by  AddiesCLK550
It is clear from the number of posts here on this topic that this item gives many of us a problem. Even if you have not already experienced a cracked third brake light (officially termed ‘center high-mounted stop lamp’) on your W209 CLK, the chances are that sooner or later you will. The design of the unit seems unable to tolerate the successive shocks that its mounting on the trunk lid is bound to inflict.

Tip: don’t slam the lid.

Editor's note: Repeat, Don't Slam the Lid! Close it gently but firmly, applying pressure only as it latches. This prevents the cracked brake light in the first place!

It is not difficult to replace the unit should you have to, even for the most inexperienced novice. Here’s a bunch of photos that I took when I replaced my cracked brake light recently. If your M-B warranty has expired, this shows you how it is easy to changeout the brake light yourself.

Image 1
my cracked rear brakelight, held together with transparent tape.

Image 2 - Parts required.
new third brake light assembly (part numbers differ according to manufacturer)

Image 3.- tools required
1. 10mm open end spanner
2. Torx 20 screwdriver
3. Pliers
4. Regular screwdriver

Open the trunk lid. Unlock the warning triangle and remove it.

Remove the warning triangle bracket, which also anchors the inner cover. This is held by a ‘spreading clip’, and to remove this you must prise up/out the center pin using a small screwdriver, and then ease out the outer clip with the screwdriver and pliers. These can be re-used so put them to one side.

Slide the bracket to the left, and use a small screwdriver to lift the inner plastic clip to free the bracket. This reverse image shows the fixings and the clip to be released on the bracket. Image 4.

Remove the trunk lid cover. To do this the 10 spreading clips that retain the cover must first be removed as described above. Image 5.



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Anyone know of the cheapest place to get this in the uk?
You can always take a chance on eBay.... but do read posts 10 & 11.
You can always take a chance on eBay.... but do read posts 10 & 11.
Tried ebay nothing on there , just waiting for a reply back from mercedes for a price for 1 , thanks anyway
Could always try the scrap yards i suppose
Many thanks for this info: Managed to complete the job by just by working on the Torx screws & removing the six clips nearest the boot latch. This gave enough room to pull the boot lining down to access the two nuts holding the light to its bracket.
Costs of the replacement would be reduced if the old light bracket was reused.
Thanks again.very generous of you to go to so much trouble on our behalf.
My 3rd brake light fell off yesterday :(
but i'll be replacin it with a new one by saturday :thumbsup:
Dealer replaced mine for free today. :thumbsup: 2004 CLK500 that I have had for about 3 months. I just mentioned that I knew it was a known issue on this model and they took care of it. Mercedes Benz of San Antonio.
I have found a new website that I order all my Genuine Mercedes Parts from.. they are by far cheaper than your local dealer. I have always gotten the parts fast and exactly the same as what the dealer would give you. If you have any questions about part numbers etc.. call them and they can look them up by your VIN... this part is $121.60 on their site...

Sometimes the part numbers don't match what your local dealer gives you.. that is why I always call this place and verify the number first.

Genuine Mercedes Parts
I just replaced this for my boss, easy install!
similar for the e320. very easy to do. $200 for part from dealership. 30min to complete myself. THANK YOU FOR POSTING THIS DYI WITH PICTURES ! THANK YOU !
As eleceel said, is the least expensive. In fact, $85 is dealer cost.
I've yet to find lower cost for new, OEM Mercedes parts anywhere else. I used this web site to order all the parts I need for my CLK and was very satisfied.
just ordered mine. will try this fix as soon as it arrives.
I would like to know how much should a rear centre brake light cost for clk200
I would like to know how much should a rear centre brake light cost for clk200
I paid £87 from a mercedes dealer in the uk , it was a bit fiddly but only took me 30 minutes to fix
thank you so so much for the clearly instruction on the 3rd light replacement and help me to save 100 buck for the labor from MB!i was changing mine under ur instructions,it very easy and cost me 15 min to do it!!thank you so much!!best regard!!cheers
Great DYI! Thank mate! :thumbsup:
I just got my replacement third brake light covers and this write up would really help me save money in sending my car to auto shop to work for it.
Mine just fell off yesterday, and then got run over in the street...

I called Mercedes today (in Vancouver), and they wanted:
$280 for the part
+$100 labour
= >$400 ?!?!

Ridiculous. I'm looking online for alternatives now. And I'm going to do the install on my own.
Just found it online for $95.

Never mind, they don't ship to Canada...
I am also in trouble of fixing my third break and I am in a small town texas, the dealer want 110 for the labour and 180 for the light, so I ordered one today for $101 +$15 shipping and see if I can do it myself~~~~~
The third brake light is a poor design - surprising coming from MB.
The problem is that the arrangement of the assembly contributes to its own
destruction (something like the Third Reich).
If you look at the arrangement, you'll see that the spring bracket actually
hangs on to the threaded studs coming from the rear of the plastic light
assembly. Every time the trunk lid is slammed down, the inertia of the heavy
metal bracket tends to force the rear of the assembly down, eventually
causing it to fail.
I have devised what I think is a solution to this problem.
The lowest price I have found for the light assembly in the U.S. is from for $91.20 plus shipping. My MB dealer matched this price (and
ignored the shipping cost).
After removing the old assembly, be sure to clean the lip of the opening in
the trunk lid. This is where the adhesive gasket of the new light adheres to the lid. Use naptha (lighter fluid), Coleman fuel, or mineral spirits. You should note that the light fits properly only one way. On mine, the part number/writing on the back of the light went in upside down.
Next, remove the paper from the gasket and insert the light into the
opening. While holding the light assembly in from the outside of the trunk, apply
silicone RTV (I used clear, but any color will do) liberally around the
perimeter of the back of the light assembly inside the trunk. It helps to have
the use of someone's small fingers to force the stuff on to the top and
Assemble the metal bracket to the light with the two nuts. This ensures that the light is positioned properly in the trunk lid. Try not to get too much RTV on the bracket. Leave it this way for about 24 hours to allow the RTV to cure.
Now remove the nuts and carefully remove the bracket by pulling it
rearward. It will have been glued to the rear of the light, so you might need to use pliers to do this. Be careful not to rock the bracket up and down too much so as not to break the adhesion of the RTV to the trunk lid and the light.
Now apply more RTV around the perimeter.
Allow another 24 hours, then reassemble the trunk lid parts.
What you have done is glued the light assembly to the trunk lid. The RTV
acts as a glue, seal, and shock absorber. It is a somewhat permanent
solution - the LED's will likely outlast the life of the vehicle. If the light is
damaged, it can still be replaced beause the RTV remains soft and can easily
be removed.
Any good RTV can be used. I used the type that comes in a cartridge that fits in a caulking gun. It is also available in squeeze tubes.
You might be tempted to leave the metal bracket bolted to the light assembly, but it really is not necessary because the light assembly is not very heavy and the RTV will hold it very securely.
Although this procedure sounds time consuming, it will likely preclude your ever having to buy another expensive third brake light.
If you experiment a few times, you'll find that it takes very little downward force to close and latch the trunk lid. This will also preclude damage to the light no matter how it was installed.
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