HOW TO: BMW Z3 (pre-facelift) 3rd brake light gasket replacement

[pangsterZ3]

A common complaint with leaks on the BMW Z3 seems to be in the boot and specifically around the third brake light - the root cause for this is because the gasket perishes over time.. it's a fairly cheap and straight forward process - but I couldn't find any guides for it so thought I'd throw one together as I've just done mine.

Tools/Parts needed:
1 x BMW replacement gasket (p/n: 63 25 8 389 735)
1 x small flat blade screwdriver
1 x medium Phillips head screwdriver
1 x T-8 precision screwdriver
1 x cloth/rag

Step 1:
Open boot and remove black plastic protective cover - this just prise away from the body work (pull it gently):



Step 2:
The PCB which powers the individual brake lights is held in place by 3 x Phillips screws -take your Phillips screwdriver and remove these (highlighted in green circles in below pictures to show location):



Step 3:
Next you need to remove the 2 x T-8 screws which hold the black plastic back plate to the front red plastic lens - these are located either side of the black plastic back plate:



All fixings should now be removed (3 x Phillips screws and 2 x T-8 screws):



All that is now holding the front lens and black plastic back plate in place are the 4 black plastic compression clips - these are located here:



All you do now is work from one side to the other pressing them (gently!) together - once you release the last clip - the front red lens and the back black plastic piece separate:



Step 4:
Remove the old gasket from the red plastic lens and replace with the new gasket:



Comparison shot of old gasket (left) and new gasket (right):


Step 5:
Take your cloth/rag and clean the area around the third brake light to make sure it is free from dirt and grime and to ensure that it's dry:


Final Steps:
Refitting is now just a reversal of removal - this can be quite fiddly though! - although once you have the red lens and black plastic backing clipped together its a fairly easy. The reason I suggested a small flat blade screwdriver above is because this will help enormously when it comes to clipping the black plastic clips onto the PCB.

Job done (and no more leaky boot!! ):


Hope this helps!!

[jmiseo2008]

Nice write up!

[pangsterZ3]

Nice write up!

thanks!! - hopefully it'll help others!

[AutoRotate]

You can go into the stickied "How-to" thread and add this one to it.

[cruzjoseo]

Is there any aftermarket light bulbs. Like leds.

[Z-Thrizzle]

Thanks for the writeup. I plan on doing it this weekend

Is there any aftermarket light bulbs. Like leds.

Yeah I just picked up a set of bulbs form superbrightleds. Do a search...someone posted the right size to get.

[Chadddada]

Does anyone have the part # for that black cover that is first removed? If you search for the 3rd brake light housing I have listed, it doesn't look like it comes with that cover. I think it may be item #26 in this list but just want to make sure http://www.getbmwparts.com/parts/200...iagram=1917375

Some other Part #s that may be worth while to list here:

Third Stoplight Housing: 63 25 8 389 734
Third brake Light Buld: 63 21 8 362 363

[gbirkemeier]

Part number for black cover for under trunk lid on a 97 is 51 47 8 398 919. I picked one up a while ago because the original kept falling off.

[Chadddada]

Part number for black cover for under trunk lid on a 97 is 51 47 8 398 919. I picked one up a while ago because the original kept falling off.

Thanks. That Part # search resolves to that component in the diagram.

[BladeRunner919]

My experience of doing this job is that clipping lens and back piece requires you to press the parts together really, really hard when installing a new gasket.

It's easy to get the impression that they have fully seated, but for the light to leak.

[dklay]

This was a great write-up and very helpful to me - I just bought my m Roadster last September and am in the process of taking care of some of it's minor issues.

I just 'tried' to accomplish this yesterday. I took my leaking 3rd brake light apart yesterday and found that there was no gasket installed! No wonder it leaked. I also found that whatever idiot had installed it without a gasket had broken off 2 of the 3 the plastic bits that the three screws for PCB go into in place (only one holding it in place).

Any helpful hints on getting the black part to 'click' into the lens?? Try as I might, I can't for the life of me press hard enough to get the clips to catch on the lens..... If there weren't a screw on each end I would have the light back in place at all..

[dklay]

FINALLY... got the lens and and black piece to 'click' together. Here's a couple of tips I found on another Z3 forum.

1. The Tabs that are supposed clip into the recesses in the lens get stiff over time and don't want to spring back and grab. Gently heat the tabs with a heat gun and bend them in a bit and allow to cool.
2. With a new gasket it's really hard to compress it enough to get the lens and black piece to click together --- I took my bench grinder and 'sanded' about 1mm off of the edge of the black peice on the side where it meets lens.

Everything went back together quick and easy after these tricks

[Vintage42]

I did the gasket today. The assembly snapped together pretty easily.

The car is a garage queen, 12,000 miles in 4 years, 10,000 miles of that with a new top that had never seen water. So I pulled out the boot carpet to see the bare metal below the sealing frame, and put newspaper in the trunk. I hosed down the rear window and the 3rd brake light and took a look. No water in the boot, but water on the newspaper.

I think the 3rd brake light had been removed perhaps when the car was prepped for sale as a CPO after its initial lease. The edge on one end of the lens was broken, which could only happen from over-tightening. And there was polishing compound on the ledge under the light; perhaps light was removed to repaint the trunk. Finally, the light just came apart as soon as the two T8 end screws were removed, indicating that it had not been snapped together to compress the gasket. No wonder it leaked.

I had a new lens and gasket on hand, and everything snapped together alright. The only problems were having to buy a precision screw driver set containing a T8 ($9 at HF), and dropping one of the T8 screws into the edge of the trunk lid. Don't let those T8s drop; if they bounce from the ledge toward the side, you might not get them out.

The edge of the lid was too pinched to let a magnetic probe get close enough to pick up the hidden screw. But moving a very strong magnet around on the underside of the lid, I could hear the screw moving and rattling. I worked it around to where the probe inside the edge could pick it up. A narrow escape, as where can you find tiny T8 screws?

[z3forlife]

Do you have Ace hardware stores ? I've found they have a good selection of metric and odd hardware/screws ect

[Vintage42]

I have use the hardware stores, and it's amazing how much they have -- walls full of trays of nuts and bolts from the Midwest(?) vendor. But I would never expect to find a T8 screw there. A tiny screw with a tiny star in the head.

[pangsterZ3]

good to see this write up is still helping people!! LOL!

[Dobr]

good to see this write up is still helping people!! LOL!

Doing mine tomorrow. Wish me luck!

[1996 Z3]

This is a great tutorial - thanks very much for posting it. I'm having a problem removing the Torx screws mentioned in Step 3 because my trunk lid doesn't have the 'notches' (seen in pic #2 of your Step 3 above) that are needed to get the screwdriver at the right angle to reach the screws. My 1996 Z3 has an early production date (03/96) and the notches in the lid must have been added at a later date. Any advice on how to reach the screws since the angle to reach them is wrong without the lid notches? Hope this makes sense. I can try to post pics if needed. Thanks for any help you can provide.

[Curt C]

Take a dremel and carefully make your own notch?