The authors take no responsibility, whatsoever, at any time, or place, or planet, for the contents of this site. Screw up your own car on your own time. BUT - we did three cars in a row. This is the easiest, best, cheapest mod you can do to your M5 to enhance brake cooling. This is absolutely a two-man job unless you have 4 hands and really long, bendy arms.
| You need only 2 parts - the left and right brake duct extensions, part numbers 51 11 7 890 013 and 51 11 7 890 014- and some medium-small cable ties (hot pink if you like - we used black.) The ducts are shown here upside down - the single hole goes toward the bottom.
OK, ready? |
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| 1. Jack up the front of the car and support it with jack stands. |  |
| 2. Remove right fender liner. You need an 8mm and 10mm socket with extension.
These lower liners take all the abuse when you exit steep driveways or have a "curb encounter". You might want to examine yours before you order any parts as you may want to replace one or both while you're at it. |
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| 3. Unsnap the thermometer from the right fender liner - then remove. Carefully pass thermometer through the liner. You can let it hang by its wire.
Remove the left liner too... |
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| 4. Remove the aluminum ducts. Ever wonder why they are there in the first place when the factory didn't connect them? Now you know - they are necessary to hold up the center lower panel. Note that there are 3 8mm bolts along the top (one way forward is a bit hard to see), and a 10mm bolt and two Phillips screws running underneath. |  |
| 5. Now that you can see what you are doing from the front, it is time to drill out the cooling holes. We found that a 1/2" wood boring bit was perfect, and that by slowing it down toward the end of the cut we got neater holes. Clean up the holes with a Dremel if you wish. Refer to later pictures for hole locations. Be careful not to drill the far inboard holes - they are too far in.
YES, I'm sweating - it was hot that day! |
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| 6. This installation stabilizes the front of the ducts to this lattice grill by means of cable ties that go around it, then back through the duct and one of the cooling holes. The lattice grill is held onto the lower bumper by means of locating pins on the bumper, held on by star washers. Push the grill rearward and drill a small hole in its lower lip. The hole should be big enough to pass the shank of the cable tie but not the head. Place a cable tie through this hole (from the front), then maneuver the grill back onto the locating pins and replace the star washer from the back. (two man job) |  |
| 7. Now maneuver the black duct into place, and, starting with the upper two ties, maneuver cable ties into place. There are already convenient holes and slits in the upper surface of the bumper to get the ties in from the front - the guy holding the duct needs to push them down into the duct through its mounting holes as he moves the duct into place. (This is the tricky part - have patience!) The guy in front has to keep hold of the heads of these two ties, and then... (This pic shows the right corner - the next one shows the left - but they are symmetrical.) |  |
| 8. Use Special Tool PN# 056-34876-CH (shown to the right) to fish the ties back through the holes in the grill, and connect them to the tie heads. Get a few clicks, but don't tighten yet. A needle nose pliers (to hold the cable tie head) and good light really help here... |  |
| 9. Now use the same technique to get the bottom tie up through the duct and connected out the front - and cinch up all 3 ties. |  |
| 10. Re-install the aluminum ducts. |  |
| 11. Find a piece of cardboard and cut it so that it can be aligned to the lower and rear edges of the fender liner. Mark the liner's location on the car, then place the cardboard template there and slowly enlarge the pattern hole until it is the right size. Once you have the template made, line it up on the fender liner, trace the hole and cut out the hole. Flip the template over and do the same for the other liner. We tried a few tools and found a Dremel with the little metal saw blade (a round disk with teeth on it, like a miniature radial saw blade) worked like a champ. "Like butta." |
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| 12. Replace the liners, put the wheels back on, and let 'er down.
Don't forget to final-torque the wheel lugs! |
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That's it. You're all done!
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This site was prepared by Greg Heumann for the benefits of all the crazies, weirdos and obsessive-compulsive driving addicts (like me) at http://www.bmwm5.com. Copyright (C) 2001 bmwm5.com. If you have questions, search the message board at bmwm5.com and search on "brake duct". You'll almost certainly find the answer. If not, post your question there and enjoy the collective expertise of over 300 M5 owners.