Polishing Front Brake Calipers for 99+ Mustangs

NOTE: This can only be done on the front on 99+ Mustang v6s or GTs. The pre 99 Mustangs have steel front calipers, and all Mustangs have steel rear calipers which will rust if polished. Do this at your own risk, as the author of this article will take no responsibility for any damaging effects caused by following (or not following) the instructions herein. In other words, proceed at your own risk. This project should not be taken on by the faint of heart, as once you start, you must finish. Also, don't lose faith halfway through and quit, as the final product does not truly show through until the last step. 

Keep in mind that this takes a lot of work to achieve a good result, so TAKE YOUR TIME. If you follow these directions and don't rush the project, it will turn out great. Also, be aware that when using the coarser of the sanding flaps, the die grinder can easily begin to "dig in" to certain areas of the caliper and create an uneven surface.  With this in mind, be sure to keep the grinder moving.   This article written by Ashentep, please do not copy without proper credit.

I will say that if someone wants this done (not only to calipers, but anything aluminum), but isn't willing to put the time into it, then I may (or may not) be willing to do this as a service.  I don't have much free time, so that will be one of the deciding factors, as is your willingness to send me the parts to be polished.  Keep in mind the larger the piece, the longer it will take, so the more I must charge.  Just contact me if you have any questions, and I'll be glad to try and help as best I can.  shastings@swcpas.com

Tools/Supplies needed: 

Die Grinder (or for the very patient and diligent a Dremel tool [not recommended]) Safety Glasses 60 grit sanding flap wheel 100 grit sanding flap wheel 400 (or as fine as you can find) grit sanding flap ***  1000 grit wet or dry sandpaper (1500 and 2000 grit should also be used consecutively to make the polishing step easier) Sanding Block Mother's Aluminum Polish Polishing wheel Buffing Cloth Electric drill  12mm socket Vise-grip pliers Jack 1-3 hours per caliper (depending on experience/patience/level of detail)

***I couldn't find a 400 grit flap wheel, and used a "fine" sanding wheel from Wal-Mart.  The Wal-Mart wheel wasn't supposed to be spun faster than 3500rpm, so be VERY careful if you use the same thing in a die grinder. The die grinder spins at ~20,000rpms, and it is possible for cheap sanding wheels or flaps to literally explode, though my particular bit did fine)***

 Step 1: Place the jack under the A-arm of the front suspension. Jack up the A-arm just enough to take some weight off the wheel. Loosen the lug nuts. Continue jacking up the car until the tire just comes off the ground. Remove the lug nuts and wheel. 

Step 2: Remove the 12mm bolts at both ends of the caliper by using the vise-grips to hold the "nut." Pull the caliper off the brake pads and inspect it, and the pads for any damage or wear. Now is a good time to replace any brake components that are needed. Also during this step, decide exactly what areas of the caliper you want to polish. I decided to polish the top (excluding the heatsink), front, and side edges. Take not that on the top of the caliper is a cast in heatsink. It has fins molded in, sort of like a radiator, to disperse heat generated by the caliper. This area would be extremely hard to polish and is not very visible with the wheel on, so it should be left alone by all but the most particular detail hound. Also, notice the 3 indentions on the face of the caliper. I skipped polishing these also, but could be polished with finer tools. 

Step 3: Rest the caliper back on the brake rotor, and mount the 60grit sanding flap in the die grinder. Use this combination to remove the "PBR" lettering on the caliper and to smooth out the casting lines on the front of the caliper facing the wheel. Be careful with the 60grit flap, as it can remove a lot of material very quickly.  Do NOT sand the curved surface between the top and side of the caliper with the 60 grit flap.  It WILL flatten it.  (You can pick the caliper up and move it around as necessary to sand all sides. ) 

The caliper should look about like this after step 3: 

Step 4: Mount the 100grit sanding flap in the die grinder, and use this flap to further smooth the surface of the caliper. This step is the most important for the side of the caliper facing the wheel, as it is the side that has the most casting lines in it. Be sure to completely flatten the entire face of the caliper and completely get rid of any casting pits or lines in this step. If you do not get the surface completely flat, the finish will not look as good.  You can now sand the curved area between the top and side without flattening it (IF you keep the grinder moving).

Step 5: Mount the 400grit sanding flap in the die grinder and use it to begin the actual polishing of the caliper. You should note that this flap does not remove nearly as much material as either of the other flaps. You should also notice that the caliper is beginning to look much better and feel much smoother. Go over the complete outer surface of the caliper at least 3 times with this grit, as the more you sand now, the less you have to do by hand and polishing later. 

Step 6: Grab the 1000 grit paper, the sanding block, and some water. Get the surface of the caliper wet and sand every surface until you think you've gotten it all, then go over all the surfaces two or more times. Again, the flatter the surface, the shinier the result will be.  A trick to this step is that the caliper will actually dull with the 1000 grit, so make sure to get every part of the surface consistently dull.  Now wash the surface off with a damp rag, and grab the 1500 grit.  Again go over the whole surface, then wash the surface and do the same with the 2000 grit.  The 2000 grit should leave the surface feeling extremely smooth.

Step 7: Mount the polishing wheel in an electric drill. Use your finger tip to apply the aluminum polish to the entire caliper and rub it in well. Using your finger tip is a small trick that works much better than applying the polish with a cloth. Once the polish has been rubbed in well, use the polishing wheel to buff the finish to a shine. Use the buffing cloth to remove what polish may be left after you use the buffing wheel. You may or may not need to polish more than one time. If the caliper doesn't reflect like a mirror now, you didn't sand enough somewhere along the way. The polishing step will bring out the imperfections of the sanding steps, so inspect the entire caliper after polishing. If there are fine scratches in the finish, go back to step 6. If there are deeper scratches in the caliper, you must go to step 5. If, however, the surface is not flat, but rather wavy (a sign that you didn't keep the die grinder moving well enough), you must go back to step 4. If you must go back a few steps, be sure to take more time the second go round, as it will pay off in the end. 

Step 8: Wash off all the aluminum flakes from the caliper, brake pads, and rotor to be sure that they will not be caught between the rotor and the pads. This could gouge the pads or rotor, and cost quite a bit to fix. Remount the caliper (reverse of removal), remount the wheel, and lower the car. Repeat for the other side. 

As a layer of protection, you may want to add a polished aluminum sealer to the surface to keep the shine for a long time.  If kept bare, the finish will begin to deteriorate, though my calipers stayed perfectly polished for about 6 months bare.  In other words, be prepared to come back again later

Results should look something like this: 

Note the face is completely flat. Also notice the 3 notches that were left alone. 

This picture doesn’t really show how it looks on the car, but gives an idea.  I apologize to those who request more pictures, but I have since sold the car to buy an '01 Cobra.

Updated 12/9/03

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