Perspective is our individual concept of the relationship between objects. The New Merriam-Webster Dictionary defines one measure of perspective as the scientific methods applied to paintings for the purpose of relaying depth and distance. Imagine coming upon a stop sign while driving a vehicle at sixty-five miles per hour. When well functioning brakes are applied, the approach to the stop sign seems reasonable and controlled. But replace the feel of solid brake pad with the spongy, bottomed-out effect of failed metal-to-metal stopping power, and the driver's perspective of the stop sign, its nearness, and the speed of his vehicle will all shift into a drastic new viewpoint. Maintaining dependable automobile braking power is critical to motor vehicle safety. Warning signs of an impending brake failure: Vehicles utilize two braking systems: drum and disc. Our focus is on disc pad replacement: how to recognize the warning signs, determine the cause, and respond to the need. Here are some pointers: Abnormal noise: grinding, squelching, or bumping sounds indicate trouble. Listen also for the high squeal of a low pad warning mechanism. Visual: metal shaving, excessive brake dust, or a sudden decrease in brake dust can all indicate a major pad issue. Physical feedback: a low pedal, a spongy pedal, a too hard pedal, a pulling or grabbing effect (either in the pedal or the steering wheel), or a vibration and back pumping pedal effect are all possible signs of impending brake failure. ABS light: this light is most often related to the brake hydraulics. It can indicate anything from low brake fluid to a bad master cylinder. When the signs indicate that something in the truck brake shoe system is out of order, try peering through the slots in the outside wheel/rim assembly (you may have to remove the wheel). The rotor is sandwiched between the inner and the outer pads. A metal-on-metal condition demands immediate attention. Otherwise, there may be a bit of time, yet anything under 1/4 inch of remaining pad surface should be addressed as quickly as possible. Too early is always better than too late. Confirmed bad: how to change brake pads Tools: we assume the mechanic is equipped with a standard tool kit, auto lift jacks, and a tire tool. However, a disc pad change-out will work easier if you have a 3/8 by 10 inch slotted screwdriver, a set of 12 to 16 inch tongue and groove pliers, and a 4 to 5 inch C-clamp. Work conditions: any place that is level and suited to the current weather. Safety: block the rear wheels, insure that the transmission is in park, and unless working on rear pads set the parking brake. Wheel lugs: loosen the front lugs, both sides. Don't take them off; just break them free of immediate pressure. Lift the vehicle: the lifting method is source dependent. Watch out for oil pans and bendable body parts. Make certain to stabilize the raised vehicle on jack stands. Tires and wheels: work on and remove only one wheel at a time. For additional safety, slide the wheel into a secure position beneath the vehicle body. Examine the components: the elements of a disc brake assembly consist of a rotor (the bright metal disc on which the tire mount bolts are attached); two heat-resistant bus brake pad that hover on either side of the rotor; a caliper (either floating or fixed) that engulfs the pads and retains them to the side of the rotor; and various clips, washers, and bolts for holding the assembly in place.