Caliper piston seals do not last forever, and once they start to leak it's the end of the road for the caliper and the pads. Fluid leaks are dangerous because they can lead to a loss of hydraulic pressure in the brake circuit that may cause the brakes to fail. Brake fluid leaking from a caliper can also contaminate the brake linings and cause them to grab or pull.
A caliper may also have to be replaced if it's sticking. Internal corrosion can cause pistons to jam or freeze, preventing the caliper from working normally or releasing completely. External corrosion on the caliper mounts, bushings or slides can also cause problems by preventing a floating caliper from moving normally when the brakes are applied. The result here may be uneven pad wear, uneven braking, dragging or a pull. With a loaded caliper, the caliper is replaced along with the pads.
Many technicians and do-it-yourselfers have learned the hard way that attempting to rebuild old calipers is often a waste of time. In many instances, the old calipers are so badly corroded or worn that they can't be rebuilt - or they leak when they are put back on the vehicle. Disassembling a caliper to replace the piston seal and dust boot is a messy job, and may be difficult or impossible if the piston is stuck in place. Steel pistons often can't be reused because they're too badly corroded, and scratches or pits in the caliper bore may cause the caliper to leak even after a new piston and seal are installed. That's why most technicians prefer to replace old calipers with new or remanufactured calipers.
Replacing the hardware is also important because old, corroded hardware can cause braking problems. We've heard of shims that have worked loose and caused a rotor to fail by rubbing and cutting through the rotor hat. If you forget to install an anti-rattle clip or installs one that does not fit properly, the newly installed pads may be noisy. Loaded calipers reduce these risks by providing the proper hardware and ensuring that everything that should be replaced is replaced.
The type of friction material that icomes with a loaded caliper assembly is critical because it should be the same as the original or better. If a vehicle was originally equipped with ceramic pads, the loaded caliper should have the same type of friction material. The same goes for semi-metallic pads.
To avoid a mismatch of friction side-to-side when installing loaded calipers on a vehicle, both calipers should be replaced at the same time. If only one caliper is being replaced, be sure to use the same friction material on both sides.
When a loaded caliper is installed, the brake system should always be flushed and refilled with clean, fresh fluid that meets the OEM requirements for the application (DOT 3 or 4 fluid).
Caliper slides and bushings should be lubricated with a high-temperature brake lubricant, and related brake components such as hoses, lines, rear-wheel cylinders and the master cylinder should all be inspected to make sure these components are in good working condition and are leak-free.
Why Remanufactured Parts?
Everybody knows remanufactured replacement parts are usually less expensive than brand new parts, but are they as good? The answer to that question depends on who supplies the parts and how much expertise and effort they put into remanufacturing their products.
There are top-quality remanufacturers that are QS-9000 certified and turn out reman products that are just as good as many brand new parts. Their prices may be 20-40 percent less than a comparable new part or an OEM part, and they typically offer warranties ranging from one year up to a limited-lifetime warranty.
There are also bargain-priced, low quality remanufacturers. Their prices are extremely competitive, but they may provide nothing more than a short-lived cheap fix. Warranties typically range from 30 to 90 days at most. These kinds of parts might be OK for a do-it-yourselfer who has a very limited budget, or somebody who is fixing a car or truck so he can sell it. But these "second line" reman parts may be no bargain if they don't last or perform like new.
The issue of quality is an important one for professional technicians because comebacks can really hurt their business as well as their reputation. If a reman part fails, the customer usually blames the shop or the person who installed it, not the parts supplier. Comebacks like these not only cost a shop the goodwill of their customers, it can also hit them hard in the pocketbook - even if the reman caliper supplier replaces the parts for free because most parts warranties do not cover installation labor.
Another benefit of using reman parts is that it recycles metal that would otherwise be thrown away. This may require a core deposit when purchasing reman calipers, but you'll get the money back when you bring in or exchange your old calipers.
REMAN BRAKE CALIPERS
The casting on a reman caliper is cleaned, remachined and returned to like-new condition. Items that are subject to wear and corrosion such as seals, bushings, caliper and wheel cylinder pistons, valves, bleeder screws, springs, etc., are usually replaced with all-new components. Most quality remanufacturers then test the parts to make sure they function correctly before they are boxed and shipped for distribution.
Reman calipers generally provide good value for the money and can lower repair costs if you're trying to save money. So if you choose reman calipers over new, go with a reputable brand that is backed with a warranty.
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WARNING: DO NOT USE OIL, GREASE, ANTI-SEIZE OR LUBRICANTS OF ANY KIND WHEN TIGHTENING LUG NUTS! Proper torque on lug nuts is very important for three reasons. One is to keep the lug nuts from loosening up and the wheel coming loose, another is to prevent distortion of the brake rotor behind the wheel, and a third is to prevent broken studs. A torque wrench should be used for final tightening of the lug nuts, and the nuts should always be torqued to the recommended specifications. CAUTION: Torque specifications for lug nuts are always for CLEANand DRY studs and lug nuts. That means no oil, no grease, no anti-seize and no lubricants of any kind. Any of these products will reduce the friction between the threads. This may seem like a good thing to prevent rust and frozen lug nuts, but the reduction in friction means a much higher percentage of the applied torque (up to 25% or more) will go toward loading the lug nuts. The end result may be brake rotor distortion or broken studs! Wheel studs should be cleaned with a wire brush to remove rust and dirt BEFORE the wheels are mounted. If the lug nuts are heavily rusted or have damaged threads and won't turn easily on the studs, replace the lug nuts. The same goes for any wheel studs with damaged or badly corroded threads. And remember to mount the wheels DRY with nothing on the threads. |
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