Brake repairs - critical? Of course! Your brakes keep your family safe. Brake repairs and parts for BMWs - expensive? You bet! Brake rotors for import cars, unlike domestics, are built with minimal thicknesses to save weight - meaning they can't be "turned"; they must be replaced.
BMW brake rotors for imports are also more sensitive to warping from heat, and overheated brakes are the second most common cause of failure (first is wear-and-tear).
Save money on BMW brake repairs and parts with these tips:
Use Your Eyes & Ears to Inspect Your BMW's Brakes
Visually inspect your brakes' condition at least every six months. Here are some things to look for:
BMW Brake Rotors (discs) should be inspected all the way around the surface and on both sides for any concentric scoring (grooves) or obvious defects. If defects are found, replace your rotors immediately. Any rotor discoloration may be a sign of overheating and an inspection by a BMW brake repair professional is needed.
BMW Brake Pads will normally match rotor scoring but should also be inspected for uneven wear, breakage or cracking on the friction surface. Again, if defects are found, replace the pads immediately. Many cars also have brake pad sensors to warn of pad wear. If your BMW uses sensors, replace these at the same time as your pads.
BMW Brake Drums (if equipped) should also be inspected on a regular basis. Check for the same types of flaws as noted above. The drums should not have excessive grooves or have a deep "trough" dug into them where the shoes ride.
BMW Brake Shoes (if equipped) should be worn evenly and have no rivets protruding to the friction surface.
BMW Additional Troubleshooting: When inspecting brakes, check calipers, wheel cylinders, hoses and fittings for any hydraulic fluid leakage.
Inspect the master cylinder, reservoir and proportioning valve assemblies as well. Replace or rebuild as required.
A "spongy" brake pedal or one that's gotten lower underfoot also needs looking into. It could be caused by sticking calipers, worn pads, low fluid or hydraulic system problems.
If you can't "pump them up", then you definitely have hydraulic problems that need work. If you always have to pump them up, at the very least your hydraulic fluid needs replacement.
To check brakes by sound, know how your brakes should sound and listen for out-of-the-ordinary noises.
Most cars have a slight brushing sound from the pads lightly touching the rotors. This is perfectly normal. Sounds to beware of include:
Squeaking may be caused by dust or dirt on the brakes, loose pads vibrating when applied or worn pads.
Rhythmic noise might mean you have a warped rotor. Instead of a solid squeaking noise, it pulsates. In extreme cases, the brake pedal will also pulsate underfoot.
Constant brake noise is never a good sound and any grinding noise spells real trouble!
Most importantly: As soon as any problem is noticed, get it repaired immediately. Delaying brake repairs is extremely dangerous.
Overstressed rotors and drums can break. Brakes may be too worn or damaged to stop your BMW in an emergency.
Even if you manage to avoid physical harm, the longer you delay fixing brake problems, the more you increase the cost of doing so.
Badly worn, warped or overheated rotors can damage wheel bearings and the complete wheel hub assembly. These parts often cost as much or more than the brakes themselves.
Even if you like doing your own work, every few years your BMW brakes should be examined by a BMW professional. Checking brakes for "run-out", warping, wheel bearing play, proper proportioning balance, among others, are normally more involved than can be accomplished in your garage. This inspection can also uncover underlying problems that could eventually become costly or dangerous.
Important Things to Remember
Heed these tips and you're on your way to ensuring your BMW brakes won't fail:
BMW Repair Tip #1: Keep the hydraulic reservoir at the proper level with the fluid type recommended by BMW. Never substitute or mix types of fluid. Remember also that hydraulic fluid absorbs water. Never use old hydraulic fluid - always use a fresh container.
BMW Repair Tip #2: Keep brakes clean by washing them off at the same time as your car. This keeps squeaky dust and dirt off the pads and makes brakes easier to inspect and work on.
BMW Repair Tip #3: Never spray, touch or drip any oil or lubricants on the brake friction surfaces. If this occurs, spray immediately with brake cleaner to remove completely.
BMW Repair Tip #4: There are no shortcuts or quick fixes to brake problems. They either function properly or they don't. Know your brake system - how it should work, feel and sound - before it acts up so you'll know when something's wrong.
BMW Repair Tip #5: Most imports don't have serviceable rotors. They must be replaced at the same time as the pads. The rotors cannot be "turned" to remove imperfections. There isn't sufficient metal thickness to safely accomplish this.
BMW Repair Tip #6: Keep a repair log with receipts when any service is performed on your BMW. It helps when you need to check if your warranty is still in effect. More importantly, it's a great gauge of performance and an indicator of other problems.
BMW Repair Tip #7: Whenever the pads are replaced, the hydraulic system must be bled to remove any air bubbles. Most BMW specialists recommend changing the fluid with every pad replacement. If you're unsure of the proper technique for bleeding the hydraulic system, don't perform the job yourself. Seek help from a BMW professional. ABS equipped cars should be bled only by professionals.
BMW Repair Tip #8: Most noises are usually related to your pads. However, whenever replacing pads, you should also replace the sensors and seriously consider replacing the rotors at the same time.
BMW Repair Tip #9: After installing new pads, remember to "set" them properly. This conditions them for maximum performance and prevents premature failure. Instructions for setting pads is usually provided in the package with your new pads.
BMW Brake Parts Shopping List
When shopping for BMW brake parts, remember two important things:
1. OEM/OES (original equipment manufactured/supplied) or equivalent pads and rotors are not always cheap. You do, however, get what you pay for. OE parts will give you the most trouble-free driving and peace of mind. And . . . isn't that what's most important?
2. Before requesting any brake parts for your BMW, make sure you have the year, exact model designation, engine size and type, brake configuration, type of rotors (solid or vented), vehicle ID number (VIN) and production date. For Volvos, you'll also need rotor diameter, caliper manufacturer and mount and shape of the pads.
Here is a list of parts you should consider when working on BMW brake systems: