If you own a 1998 Jeep Cherokee XJ, you know it is a legendary off-road machine that refuses to quit. However, even the most durable vehicles need maintenance, and the rear drum brakes are a common point of wear. For many DIY enthusiasts, the thought of tackling drum brakes can be intimidating, often leading to expensive shop or frustrating afternoons with springs flying across the garage. This guide is designed to demystify the entire process, providing you with a clear, diagram-driven approach to installing new rear drum brakes on your XJ.
Understanding how to perform this job yourself is not just about saving money; it is about gaining confidence in your vehicle’s safety and reliability. In this comprehensive article, you will learn the exact components involved, the tools required, and a step-by-step procedure that mirrors a professional mechanic’s workflow. We will break down the complex spring and shoe arrangement into a simple, visual process, ensuring that by the end of this guide, you can complete the installation with precision and ease. Whether you are a seasoned wrench-turner or a first-time XJ owner, this guide will equip you with the knowledge to get the job done right.
Understanding the 1998 Jeep XJ Rear Drum Brake System
Before you touch a single wrench, it is critical to understand what you are working with. The 1998 Jeep XJ uses a duo-servo drum brake system on the rear axle. This design is known for its powerful self-energizing effect, meaning the rotation of the drum helps pull the shoes into the friction surface, increasing stopping force. The system consists of several key components: the backing plate, wheel cylinder, brake shoes, return springs, hold-down springs, self-adjuster mechanism, and the parking brake lever. Each part plays a specific role, and a failure in any one of them can lead to poor braking or complete brake.
The most common issue with the XJ’s rear drums is that the self-adjuster mechanism seizes up due to rust and road grime. This leads to excessive pedal travel and uneven shoe wear. Additionally, the wheel cylinders are prone to leaking brake fluid, which contaminates the shoes and reduces braking efficiency. When you purchase a replacement kit, it typically includes new shoes, springs, and an adjuster assembly. However, you should always inspect the wheel cylinders and drums themselves for scoring, cracking, or excessive wear. A good rule of thumb is to replace the wheel cylinders whenever you replace the shoes, as the labor cost of doing it later is high.
For the 1998 model year, the XJ uses a 10-inch drum brake system. The axle is typically a Dana 35 or a Chrysler 8.25, but the brake hardware is identical for both. A common mistake is mixing up the primary and secondary shoes. The primary shoe is shorter and faces the front of the vehicle, the secondary shoe is longer and faces the rear. Installing them backward will result in poor braking performance a dangerous driving condition. Always lay out your new parts in the order they will be installed, referencing a diagram to ensure correct orientation.
Essential Tools, Parts, and Safety Preparations
Key Takeaways
- ✓ Always replace the wheel cylinders and hardware kit when installing new shoes to prevent future leaks and ensure proper spring tension.
- ✓ The primary shoe (shorter) must face the front of the vehicle; the secondary shoe (longer) faces the rear. Installing them backward is a critical error.
- ✓ Use the two-bolt method to remove a stuck drum; never pry on the drum edge with a screwdriver.
- ✓ Adjust the star wheel until the drum locks, then back off 10-15 clicks for proper clearance and self-adjuster function.
- ✓ Bleed the brakes in the correct order (rear passenger, rear driver) and check the master cylinder fluid level frequently to avoid introducing air into the system.
Frequently Asked Questions
Why is my brake pedal going to the floor after installing new rear drums?
This is usually caused by air in the brake lines or the self-adjuster set too loose. First, re-bleed the brakes, starting with the rear passenger side. If the pedal is still soft, check that the star wheel is adjusted correctly. You may also have a leaking wheel cylinder, which will introduce air into the system. Inspect the backing plate for fresh brake fluid.
Can I reuse the old brake springs and hardware on my 1998 XJ?
It is not recommended. The springs lose tension over time due to heat cycles and corrosion. Weak springs cause the shoes to drag or fail to retract, leading to premature wear and poor braking. A new hardware kit is inexpensive and includes all the springs, clips, and the adjuster assembly. Always replace the hardware when you replace the shoes.
How do I know if my brake drums need to be turned or replaced?
Inspect the inner friction surface of the drum. If there are deep grooves, scoring, or a lip on the edge, the drum should be turned (machined) or replaced. Measure the drum’s inner diameter with a brake drum micrometer. If it exceeds the manufacturer’s maximum diameter (usually stamped on the drum), it must be replaced. A warped drum will cause a pulsating brake pedal.
What is the correct torque for the wheel cylinder bolts and lug nuts?
The wheel cylinder bolts should be torqued to 10-15 ft-lbs. Over-tightening can warp the cylinder body and cause leaks. The rear lug nuts on a 1998 XJ should be torqued to 85-95 ft-lbs. Always use a torque wrench for lug nuts to prevent wheel warpage and ensure the wheel is seated evenly.
My parking brake does not hold after the install. What did I do wrong?
The most common cause is that the parking brake cable was not properly connected to the lever on the shoe, or the cable is stretched. Ensure the retaining clip is fully seated. Also, check that the self-adjuster is working correctly. If the shoes are too loose, the parking brake will have excessive travel. If the is stretched, it may need to be adjusted at the equalizer under the vehicle, or replaced entirely.
Conclusion
Installing rear drum brakes on a 1998 Jeep XJ is a rewarding task that saves money and deepens your connection with your vehicle. By following this step-by-step guide understanding the diagram of the duo-servo system, you learned how to safely disassemble, replace, and adjust the brakes. The key to success lies in preparation: having the right tools, using a complete hardware kit, and paying close attention to the orientation of the primary and secondary shoes. Remember that bleeding the brakes and performing the final adjustment are not optional steps; they are critical for safe and effective braking.
Now that you have the knowledge, it is time to put it into practice. Gather your tools, order your parts, and set aside a Saturday morning to tackle this job. Your XJ will reward you with confident stopping power and the satisfaction of a job well done. If you encounter any issues, refer back to this guide or consult the XJ community forums, where thousands of owners share their experience. Drive safe, and enjoy the reliability of your properly maintained 1998 Jeep Cherokee.
“Cars aren’t just machines. They’re freedom, memory, and a little bit of grease under your fingernails.”
I’m Theodore Roosevelt—though my friends just call me “Ted” (and no, I’m not related to the president, though I do share his love for adventure). I grew up in Detroit in the 1970s, back when the city was still the heart of the American auto industry. My first love was a rusted-out 1967 Mustang my father and I rebuilt in our garage when I was fifteen. That project taught me that cars have souls. After spending twenty years as a mechanic and another ten writing for magazines, I started this blog to help everyday drivers and weekend wrenchers feel confident under the hood. Whether you’re restoring a classic or just trying to keep your daily driver alive for one more winter, I’m here to help you get there.
