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Caliper Clinic: Defective Parts, If Not Monitored, Can Easily Strip A Company Of Its Profits

By Paul Schuck

Defects exist in almost all products. Preferably, defects are found and corrected prior to shipment to the customer. However, on occasion a defect can be overlooked and end up in the customer's hands. Not all defects result in an unsafe condition. But even a product that is boxed or labeled incorrectly can leave the customer with a sour taste in their mouth long after the issue has been resolved.

Defective parts, if not monitored, can easily strip a company of its profits. An automotive parts rebuilding association has been quoted in the past as saying that the automotive hydraulic parts industry has an average of between 4%-6% warranty and defects rate. Defects as well as warranty claims not only affect a company's profits; they erode customer confidence in a specific rebuilder's product as well as potentially that of all rebuilt products. With the stakes this high, anyone can see why it is so critical to be able to define the root cause of defects and warranties and to take corrective action quickly.

Defects and warranties can be separated into two categories - Actual and Alleged. This is important not only to harness a customer who may be manipulating you for their own benefit, but also to show you which customers actually need to learn proper diagnostics and installation procedures. Additionally, separating actual from alleged warranties will allow you to focus your efforts on correcting actual root causes of a return.

Some people are unaware of the difference between a defect and a warranty. A defect is a fault or imperfection of a part prior to installation or use. A warranty is a defect that has affected the integrity or implied performance of a part. In most cases, a warranty occurs after the part has been installed.

To help define these further, some common examples of brake caliper defects and warranties are listed below. Note that the types of defects and warranties listed below may be caused by an actual defect at the rebuilder's facilities, however, it is possible to cause many of these same conditions while installing the product on the vehicle.

Types of defects
Stripped Threads - May have been damaged during rebuilding, however, it's also possible that the damage was done by the customer during installation.

Missing Parts - Parts may have been left out during rebuilding or possibly pilfered by the customer.

Leaks - Seal damage may have been done during piston installation by the rebuilder, however, it's also possible to damage a seal with extreme heat or contaminated brake fluid.

Boxed incorrectly - The box may have been labeled incorrectly, but occasionally the customer orders the wrong part number and simply needs to return the one that was sent.

Caliper will not fit - A caliper that will not fit over the rotor could be caused by brake pads that are too thick, an incorrect bracket, or a piston that is too long. On occasion the cause is a rotor that is too thick.

Types of warranties
Stuck piston - The use of a substandard piston will cause sticking, however, using contaminated fluid may also cause the seal to swell and the piston to stick. Extreme heat around the seal area can also affect piston movement.

Premature pad wear - There are many things that can affect brake pad wear, however, there are some telltale signs that may help determine the true cause. Extreme inner pad wear with normal outer pad wear can be caused by seal swell or piston damage, but it can also be caused by riding the brake pedal such as in "two-footed driving."

Extreme outer pad wear with normal inner pad wear can be caused by slides, pins, bolts or bushings that are binding or stuck due to lack of lubrication or incorrect lubrication. With this type of situation it is common to find petroleum-based lubricants were used and caused swelling of the rubber which caused the caliper to bind.

Extreme pad wear on both inner and outer pads may be caused by an improper rotor surface, a damaged brake line or hose, or simply aggressive driving habits.

Loose parts - Loose parts may be due to incorrect parts or parts that were installed incorrectly during rebuilding. However, don't rule out a worn casting or possibly incorrect installation by the customer.

Noise - Noise is probably the most common brake complaint when only brake pads have been replaced or when it is required that the technician assemble the hardware and brake pads into the caliper. An improper rotor surface, improper lubrication, loose brake pads or foreign material that has contaminated the friction surface can also cause noise.

The chances of noise can be greatly reduced when the caliper has all pads and hardware properly attached and lubricated. Constrained layer shims can further aid in noise control.

Because many customers will not use a warranty card or take the time to write out the reason for each return, it may be difficult to determine the reason for the return. Incorporating check-off boxes with common return reason(s) printed on the package will allow the customer to fill in the reason easily. It will also ensure that the product is returned in your box.

All product returns should be isolated from all other inventory until the return can be inspected and the true cause identified. Each customer return should be logged on a spreadsheet that lists the product part number, alleged problem and your findings.

One common check that often gets overlooked is to verify that the returned part is actually a part that you produced. Separating product returns into different categories and carefully reviewing them on a regular basis will allow you to determine where there may be production problems, incorrect or substandard parts or materials, incomplete procedures, lack of training or possibly a customer that is "playing games" at your expense. Once this information is determined, what you do with it is up to you.

As you can see, determining the true cause of a return may not always be easy. However, it will tell you a lot about what you may be doing wrong. It may also tell you a lot about your customer or your customer's customer as well.