DIY Jeep Brakes

Jeep models and products have changed over the 50 years of the company's existence, but the basic principle of braking systems has changed very little. Most Jeeps have a front disk, rear drum brake system, with modern models having four wheel disk, and older Jeeps using four wheel drum style brakes. Changing the brakes will take the average backyard mechanic about 30 minutes per brake.

Front Brakes

In the mid-1970s, Jeep rolled out front disk rotors with pads and calipers, which apply friction to stop the Jeep better than the previous drum system. The Jeep retained rear drums until the mid-1990s, when all four disk brakes were introduced. Repair of the disk brakes involves removing the front wheel by jacking up the frame rail and turning the lug nuts counterclockwise, then taking the caliper off of the rotor by unbolting the two mount bolts at the rear of the caliper. The rotor design has changed over the model years, with the addition of a spindle nut and sealed front wheel bearings. With the rotor off, it can be resurfaced and replaced, followed by the caliper and wheel. New pads should be applied whenever the rotor is changed, so that they mate well. Worn pads and a new rotor do not mate well.

Rear Brakes

The drum style brakes that were on the rear axle of older-model Jeeps can be removed in a similar fashion. Jack up the wheel, remove it, and then remove the large drum that covers the brake shoes and assembly. Later models have rear disk brakes, which still incorporate a drum system within their rotors, because calipers cannot be cable-operated. The shoes can be removed by levering off the main springs with a screwdriver or brake tool, then turning the primary spring bolt in the center of each shoe counterclockwise. The shoe slides out toward the front of the assembly. For the rotor/drum combination, remove the rotor as described in section 1, then remove the shoes mounted onto the hub. The rotor/drum combo is actually a double-sided friction surface, and should be replaced rather than resurfaced. Resurface the drum-only style, and replace the springs and drum in the reverse order of removal.

Purging

Typically after the brakes have been replaced or repaired, it is normal to "bleed" the brake lines by opening the master cylinder (under the hood on the driver's side firewall), and continuously pouring in DOT-3 brake fluid with the bleeder nipples opened one at a time. This is usually a two-person job, as someone needs to press the brake pedal while someone else pours the fluid. The bleeder nipples are located on the back of each caliper and on the back of each drum brake assembly (at the top, near the wheel cylinder). Turn them counterclockwise to open, clockwise to close. The fluid should be poured until the stream coming out of the nipple is golden yellow and bubble-free. Once the lines are bled, close the nipples tightly and top off the master cylinder to the correct level.