For Rear Drum Brakes (Most Common):
The adjustment is typically done using a star wheel located inside the backing plate. You'll need to:
1. Jack up the truck and secure it on jack stands. Safety first! Never work under a vehicle supported only by a jack.
2. Remove the wheel.
3. Locate the access hole in the backing plate. This is usually a small, round hole. You may need a flashlight to see it clearly.
4. Insert a screwdriver (often a flathead) into the access hole. You'll feel the star wheel.
5. Turn the star wheel. Turning it clockwise tightens the brakes, and counter-clockwise loosens them. Turn it a small amount at a time, then rotate the wheel to check for drag. You want just enough tightness to eliminate play in the brake pedal but not so much that the wheel is difficult to turn.
6. Repeat for the other rear brake. Ensure both sides are adjusted similarly.
7. Reinstall the wheel.
8. Lower the vehicle.
9. Test the brakes thoroughly. A test drive is crucial to ensure proper braking performance.
Important Considerations for Drum Brakes:
* Adjusting too much: Over-tightening can cause the brakes to drag, leading to overheating and potential damage.
* Adjusting too little: Insufficient adjustment results in a soft brake pedal and reduced braking power.
* Worn Brake Shoes: If your brakes are frequently requiring adjustment, it's likely your brake shoes are worn and need replacing. Regular inspection of the shoes is recommended.
* Brake Drum Condition: A scored or damaged brake drum can also lead to poor braking performance and frequent adjustments. Consider replacement if necessary.
For Rear Disc Brakes (Less Common):
Rear disc brakes on a 1997 Silverado would require a different adjustment procedure. They generally don't have a manual adjustment like drum brakes. Instead, they rely on the caliper's piston to maintain the brake pad contact. If you have rear disc brakes, you would likely need to:
1. Inspect the brake pads for wear. If worn, they need replacement.
2. Check for sticking calipers. A seized caliper piston will cause uneven braking and may require repair or replacement.
If you are unsure about whether you have drum or disc brakes, or if you're uncomfortable performing this task, it's best to consult a qualified mechanic. Working on brakes is a safety-critical task and incorrect adjustment can lead to dangerous situations.
