Like all modern systems, the anti-lock brake system relies on a lot of information and input in order to function properly. Without an ABS speed sensor ring (located within the speed sensor) to monitor the speed of your wheels, and signal the activation of the entire system, all you have are over-priced brakes. If you need a new speed sensor ring for that ABS, then we have the no-nonsense guide to helping you get one.
One ABS, many designs
One would think that a system as "standard" today as the anti-lock braking system would be fairly similar across all makes and models. But the thing is, there are actually different designs-each design requires only a specific number of speed sensor rings at only specific locations. So, we'll discuss the different designs only insofar as to help guide your purchase.
Considered by many to be the best arrangement because it maximizes the number of channels used, ABS in this arrangement have speed sensors on all four wheels. If you're looking to replace one or more of the rings in these sensors, you have to consider if the replacement is a fit for the front or rear, then driver- or passenger-side.
This design is usually found on lighter trucks that have ABS on all four wheels. The speed sensor has an incorporated valve for each of the front wheels. In the rear, there is only one speed sensor for both of the wheels-additionally, its location on the rear axle means that it is vastly different in size and appearance.
Pickup trucks with rear-wheel ABS utilize the single-channel design. This design uses only one sensor for the entire ABS. Again, this is located on the rear axle, making the appearance and size radically different from sensors located on the wheels bases themselves.
The smart choice
Though the size differences among the actual rings themselves is very small-in the order of a couple of millimeters-you have to realize that these rings need to be an exact fit in order to function properly. Once you've identified-using the guide above as reference-the specific system installed in your vehicle, the next step is to confirm that the ring is a match. The simplest way is to check for a part or manufacturer's number as these are used to help make purchasing easy. You can readily find these etched on the rings themselves or, failing that, in your ride's manual.