Once your cars brakes reach a certain age about 5 years or more you will have probably gone through a few sets of brake pads and possibly a set of rotors. During that time if you haven’t been doing the work yourself or if you happen to buy a used vehicle your disk brake calipers are likely to have collected a lot of surface rust.
Just because your calipers have surface rust is no reason to replace them. Although remanufactured or even new aftermarket calipers for many smaller vehicles can cost under $75 a side the OEM calipers should be able to last 200,000 miles with no problems.
If you find that a caliper seal is leaking you can replace them for only a few dollars with only a few hand tools and this is also true for other parts of the caliper like caliper bushings and pins that can get worn or deteriorate.
All of the parts above effect the way the caliper works and its ability to stop your vehicle. However when you are working on an older set of calipers with a lot of surface rust it can be dirty and more difficult then a detailed pair.
If you have a newer vehicle and you install a set of aftermarket wheels that expose the caliper then you may want to perform this work long before your brakes need it just to improve the look of your car.
What Type Of Paint Is Best?
Aftermarket calipers that come painted are often powder coated in the factory. This type of paint is baked on and provides a very good surface to repel brake dust, oils and road salt. If you happen to have or are thinking of buying your own powder coating system I would not suggest that you perform the work yourself on brake calipers, drums or rotors.
Although the powder coating baking process is below the maximum heat range that many of the parts will see during operation the metals used in brakes are formulated to provide the maximum hardness for better stopping. When you heat the parts for a prolonged period there is a slight possibility that you could change the metal properties and end up with parts that warp quicker and perform less effectively over time.
If you wish to powder coat your brake parts then take them to a professional that not only powder coats automotive parts but specifically brake parts.
Spray Paint
For the rest of us who don’t own a machine shop we have the option of using high temperature spray paint. Caliper paint is rated to 900F this is 500 degrees higher then engine enamel so you should not interchange the two products or you are likely to see short life on your project.
Preparing The Parts
Caliper Paint must be applied to clean dry surfaces which means you will need to clean your parts with a wire wheel and brushes prior to painting.
This job should be performed just prior to installing new brake pads. Although you can protect areas by masking and clean the surfaces with brake cleaner to remove overspray the best results will be found by replacing your pads after you have detailed and thoroughly cleaned and painted all the parts you wish to restore.
Any maintenance such as replacing bushings or seals should also be performed after you have cleaned and painted your calipers.
Using a 4 inch grinder with a wire wheel will provide a quick way to remove a large amount of surface rust. You will need to determine if you need to remove your brake banjo line and this may be reasonable if you have a lot of rust. If you do remove it you will need to bleed your brakes after the work is done.
Remove your rubber bleeder valve protector and use a few layers of aluminum duct tape to protect your rubber caliper pin bushings.
Clean the brakes thoroughly with brake cleaner to remove any brake pad dust you may inhale.
You MUST wear a dust mask. A heavy dust mask is best and should be rated not only for standard shop use but for brake work. They only cost about a dollar so get a couple.
YOU MUST WEAR EYE PROTECTION wire wheel fibers will fly off of the wheel during this extended grinding procedure along with a lot of rust and it will get in your eyes… there is no may about it .. it WILL get in your eyes.
Allow the grinder to do the work with only light pressure. If you have a large amount of rust like the brakes I am working on in the picture you can expect the procedure to take between 30 and 45 minutes per side just to remove most of the surface rust.
While grinding you will notice that when the metal is clean it will turn gray in color like a brand new frying pan this is because the parts are a type of cast iron.
You should be able to remove about 90% of the rust with your grinder and wire wheel but you will have to work some areas with a small toothbrush sized steel brush.
Once you have removed all the rust that you can you should clean the surface with water and then compressed air, then finally with brake cleaner.
You will need to allow the brakes to dry before painting.
Painting The Calipers
Even though you will be replacing your brake pads it is important to protect protect the parts you do not want paint on. Cover your axle threads with masking tape and use newspaper to protect other large areas.
In this detailing paint will also be applied to the hub area of the rotor. It is not expected that the paint applied in this area will last for a long time because of the heat produced but it will give some added protection.
The rotors will most likely need resurfacing or replacement some time in the future so the disks are not masked off. If you are painting your calipers in place and not removing them like is done here then you may want to mask them off with plastic or newspaper.
Unlike painting a fender you do not want to first apply a thin tack coat on cast iron. You should apply a full wet coat so that the paint soaks deep into the porous surface. Allow your first coat do dry for at least 15 minutes and then follow up with a second or third coat as needed.
When you start your painting you want to hit the groves or deeper edges quickly and then come back and apply a long brushing type stroke across the whole surface.
One can should be enough to do two calipers with a little left over. You may want to come back after the calipers are done and hit your backing plates just to clean them up.
Final Note
This is a labor intensive job and it is both dirty and could be dangerious if you do not use the correct protection such as very good eye protection or goggles that seal tight to your face and a good dust mask or respirator.
About half way through you are likely to ask yourself why you didn’t fork out that $150 for new calipers instead of paying $15 to do the job yourself but in the end you should be happy with the results.
Heat is a problem for keeping your surfaces painted and clean. You can expect to redo your work every 100,000 miles or so depending on your driving conditions.
If you are purchasing new Calipers then you should clean the parts of machine oil and then apply paint prior to installing them.