Description & Operation

Wrangler is equipped with standard front disc and rear drum brake system. A 4-wheel disc brake system is optional on some models. Anti-Lock Brake System (ABS) is also optional. See appropriate ANTI-LOCK article.

As brake pedal is depressed, hydraulic pressure passes through a proportioning valve to brake caliper piston. This force is transmitted to inboard brake pad, forcing it against braking surface of rotor. Pressure then moves outer caliper housing and pad inward on caliper mounting bolts, forcing outer pad against outer braking surface of rotor.

All models use a floating single piston caliper disc brake assembly on the front and rear. A ventilated disc brake rotor is used on the front. Cast brake drums are used on the rear. Models with 4-wheel disc brakes use a solid rotor on the rear. A brake drum is cast into the middle of rotor for parking brake.

All models use a combination valve containing a rear brake proportioning valve and a pressure differential switch. Proportioning valve operates by restricting hydraulic pressure to rear brakes at a given ratio when system hydraulic pressure reaches a certain point. This improves front-to-rear brake balance during high speed braking, when a percentage of rear weight is transferred to front wheels. Valve reduces rear brake pressure and delays rear wheel skid. On light brake application, valve allows full hydraulic pressure to rear brakes. Proportioning valve is not serviceable and must be replaced if faulty.

Two brake warning lights may be used. A Red BRAKE warning light is in circuit with pressure differential (brake warning) switch and parking brake switch. Red BRAKE warning light will come on for 2-3 seconds during start-up as a bulb check, when parking brake is applied or when there is a pressure differential between front and rear brakes indicating a system leak. On models equipped with ABS, an Amber ABS light is used. Amber ABS light will come on for 2-3 seconds during start-up as a bulb check and when an ABS fault occurs.

Parking brake system uses a cable mechanism to actuate standard rear brakes for parking or emergency service. Parking brake system on 4-wheel disc brake models uses cable actuated dual brake shoes secured to backing plate. Parking brake drum is cast into rear disc brake rotor.