Brakes – Page 2 – UnderstandYourCar

If you’ve never installed your own brake pads before, the installation process is a whole lot simpler than you might realize. One problem that newbie DIY mechanics face, however, is that both the inside and outside brake pads look almost identical. So, which one goes on the inside? If the brake pads do not come with “inside” and “outside” indicators, then it doesn’t matter which one goes on the inside and which one goes on the outside, as they are usually identical. There are a few different types of brake pads, at least in terms of how they are shaped. For the most part, the inner and outer ones are identical and interchangeable, unless you specifically see instructions or indicators marked directly on the pads. How Do Brake Pads Work? If you know how brake pads work, it's pretty easy to understand why the inside and outside brake pads are generally interchangeable. No matter what shape the brake pads come in, they typically work the same. The brake pads are held in place, on opposing sides of the rotor, by the brake calipers. The rotor is the smooth, thick steel plate hidden just behind the wheel. When you take the wheel off of your vehicle, you will see the rotors with the caliper attached over the top, concealing the upper portion of the rotor like a hood. The caliper both holds the brake pads in place and contains the small tubes that carry pressurized brake fluid to the brake pads. When you stomp on the brake pedal, the brake fluid serves as a strengthening agent. The pressure and the nature of the brake fluid increase the pressure of your foot a hundredfold. When you press the brake pedal, a series of mechanisms push the drums inside of the caliper towards each brake pad. The brake pads, pressed forward by the drums, come into hard contact with the spinning rotor, using friction and strength to stop the rotation of the wheels, bringing your vehicle to a halt. Brake Pads that are Marked When you install your brake pads, they go directly into the caliper, which is then placed back over the rotor, with a brake pad on each side of the caliper and the meat of each brake pad facing the rotor. If your pads are marked L and R, then you must assume that they are aligned as if you are in the driver's seat, facing forward. That means that the L pad will be on the outside if you are installing the brake pads on the driver's side rear or front. The L pad will be on the inside if you are installing the pads on the passenger side rear or front. Some brake pads are simply labeled with “inside” and “outside” indicators. That means that no matter which brake pads you are installing, the “inside” marked pad will always go on the inside of the rotor. While most brake pads are interchangeable, you will notice that brake pads that are made with indicators may have a very slight difference in their overall aesthetic. If your vehicle is FWD (Front Wheel Drive), you will notice that the front brake pads are generally much larger than the rear brake pads. The same holds true in the opposite way if you have a RWD (Rear Wheel Drive). Sometimes, with AWD (All Wheel Drive) vehicles, there will still be a difference in the sizes of the brake pads, with the larger brake pads up front, where most of the weight is from the engine. Brake Pads with Wear Indicators These brake pads have indicators on them that have nothing to do with whether or not you place them on the inside or outside unless only one of the two pads for each rotor has the marking. The wear indicator is a marking that you can usually see through the wheel or by looking inside the wheel well. It tells you if your brake pad has worn down far enough that you need to install new ones. Sometimes, the wear indicator is designed for your particular style of vehicle and only on the outside pad, because that makes it easy to spot, without having to remove the wheel and tire. If this is the case with yours, you will know that the brake pad without a wear indicator is the one that goes on the inside. Sometimes, the wear indicator will go on the inside brake pad and not on the outside brake pad. This will be indicated when you remove them from the box, either by the paperwork that comes with them or by the markings on the pads. Usually, if you have a wear indicator, you will also have a left, right, inside, or outside indicator as well, so there is never any confusion as to where the wear indicator should be located. What Happens if You Install Them the Wrong Way? As we mentioned above, not every pad is marked and most brake pads are virtually identical. If they aren’t marked and have the same size and thickness, it really isn’t going to matter which side you install them on. Even when your brake pads have clear markings to indicate which side they go on, you will still be fine if you place the outside one on the inside and vice versa. This is only true if the brake pads are identical, which they are in most cases. If there is a slight difference in the two pads—as we mentioned above, the difference may be very subtle but still noticeable—you need to make sure you get the right one on the inside and the outside. Manufacturers who put together brake pads like this will always have indicators on each pad. All Things Considered Most of the time, it doesn’t matter which brake pad goes on the inside and which one goes on the outside, even if they have markings that indicate otherwise. However, you should always pay close attention to the size and shapes of each brake pad that comes out of the box and read any instructions or indicators carefully.