To adjust the rear drum brakes on an older BMW, start by lifting the car securely and removing the rear wheels. Use a 13mm or 14mm wrench to tackle lug nuts, then locate the adjustment hole in the backing plate. With a flashlight, find the star wheel adjuster inside. Turn it clockwise to tighten, counterclockwise to loosen. You typically need about 3 to 5 clicks. Spin the drum to ensure smooth movement. Finish with a short test drive, making sure the brake feels firm and responsive. Explore further intricacies involved in this essential maintenance task.
What Tools Do I Need to Adjust BMW Drum Brakes?
Start your BMW rear drum brake adjustment with the right tools to ensure a smooth and efficient process. Having a comprehensive set of tools and safety equipment is crucial for tackling this task effectively.
Here’s what you’ll need:
- Flathead Screwdriver: Essential for accessing the adjuster through the drum.
- Socket Set (13mm and 14mm): Used for removing the drum and associated hardware.
- Pliers: Handy for handling spring components securely.
- Flashlight: Helps illuminate the assembly and adjuster location.
- Hub Puller: Useful for removing stubborn drums due to rust or wear.
Safety is paramount—wear gloves and safety goggles to protect against sharp edges and debris.
A brake spring tool can also assist in safely handling brake springs without causing damage.
How Do I Access the Rear Drum Brake Assembly?
To safely access the rear drum brake assembly on your older BMW, begin by positioning the car on a flat surface.
Securely lift the rear using a hydraulic jack, and place jack stands beneath the vehicle’s designated lifting points. This prevents accidental collapse. Make sure to disengage the parking brake before lifting.
- Use a 13mm or 14mm box-end wrench to loosen the lug nuts.
- Remove the rear wheels.
- Inspect the drum brake assembly for visible issues.
- Locate the adjustment holes on the backing plate, removing any rubber cover if present.
- Align the bolt hole at the top of the drum for better visibility of the star wheel adjuster.
Once adjustments are made, carefully reinstall the wheels and tighten the lug nuts to BMW’s specifications before lowering the vehicle.
Step 1: Safety Preparation
Before you start adjusting your BMW’s rear drum brakes, ensure the car is parked on a flat surface and secured with jack stands to prevent any movement.
Use wheel chocks to stabilize the wheels, and remember to wear safety glasses and gloves for protection against debris.
Disconnect the battery’s negative terminal to avoid accidental electrical issues while you work.
What Safety Measures Should I Take Before Starting?
Start by parking your vehicle on a flat surface and engage the parking brake to prevent any movement. Secure the front wheels with sturdy chocks to avoid accidental rolling during the process.
For BMW models, use a hydraulic floor jack to lift the car's rear, and place jack stands under the designated lift points for added stability.
Always wear safety goggles and gloves to protect yourself from debris and sharp parts.
Before proceeding with adjustments, closely inspect the brake components for any signs of wear or damage.
This careful preparation ensures a safe and effective repair, reducing the risk of accidents and maintaining brake performance.
Step 2: Initial Inspection
Start by lifting your BMW securely on jack stands to access the rear drum brakes.
Check the brake shoes for any signs of uneven wear or thinning, as common in older BMWs, using a brake gauge to measure their thickness.
Ensure the hardware, including springs and adjusters, is intact and free from corrosion, which can affect brake performance.
How Do I Check the Current Brake Condition?
A thorough inspection is crucial to ensure the effective performance of your BMW's rear drum brakes. Start by visually inspecting the brake shoes for uneven wear, particularly on one side. This might signal misalignment. Use a caliper to measure the brake shoe thickness, ensuring it's at least 3mm. Examine all brake hardware, like springs and retainers, for rust or fatigue.
Check for wear patterns typical in BMWs:
| Inspection Point | Sign of Wear | Action Needed |
|---|---|---|
| Brake shoes | Uneven wear | Check alignment |
| Brake hardware | Rust or fatigue | Replace if necessary |
| Drum surface | Scoring, pitting, or edge lip | Resurface or replace |
| Flexible brake lines | Leaks or swelling | Replace immediately |
Inspect the drum surface for any scoring or a lip, indicating the need for resurfacing.
Step 3: Adjustment Process
To adjust your BMW’s rear drum brakes, locate the star wheel adjuster through the access hole on the backing plate.
Turn the adjuster clockwise to tighten the brake shoes or counterclockwise to loosen them, typically needing about 4 to 6 clicks for proper adjustment.
After adjustments, spin the drum to ensure it rotates smoothly without binding, making further tweaks as necessary.
What Is the Correct Method for Adjusting BMW Drum Brakes?
Accessing the star wheel adjuster on your older BMW's rear drum brakes requires removing the rubber cover on the backing plate.
Once exposed, locate the adjuster at the 9:30 or 2:30 position. Use a flathead screwdriver to rotate the star wheel. Turn it clockwise to tighten the brake shoes or counterclockwise to loosen them. Typically, you'll need about 3-5 clicks for proper adjustment.
Align the wheel so the bolt hole is at the top, making it easier to see the adjuster. After adjusting, spin the drum. You should feel slight resistance without continuous rubbing.
Reassemble the components and replace the rubber cover. Finally, press the brake pedal to ensure proper engagement before driving.
Step 4: Testing and Verification
To confirm your brake adjustment is correct, begin with a short test drive.
Observe the brake pedal—it should feel firm, not too soft, and shouldn’t travel too far when pressed.
Ensure the car stops smoothly without pulling to one side, and listen for any unusual noises like grinding or squeaking that might suggest further adjustment is needed.
How Do I Know If the Adjustment Is Correct?
Once you've adjusted the rear drum brakes on your older BMW, it's crucial to verify that they're functioning correctly.
Start by checking the brake pedal travel. It should engage quickly with minimal travel. A firm and responsive pedal indicates proper adjustment.
During your road test, ensure the car stops smoothly without pulling to one side. This confirms that the brakes are evenly adjusted.
Listen carefully for any unusual noises like grinding, which could mean the brake shoes are off.
Test the parking brake; it should hold securely without excessive movement.
If the pedal feels spongy, there might be air in the brake lines.
Make sure all these checks confirm the brakes are operating normally for safe driving.
What Are Common Mistakes to Avoid?
When adjusting the rear drum brakes on an older BMW, it’s crucial to avoid several common mistakes. Over-tightening is a frequent error that can cause the brake shoes to bind against the drum. This leads to overheating and premature wear.
Ensuring the parking brake is fully released before adjustment is vital to prevent improper shoe positioning.
Here’s a list of common pitfalls:
- Over-tightening: Causes binding, overheating, and rapid wear.
- Parking brake not disengaged: Leads to incorrect positioning.
- Neglecting cleanliness: Skipping cleaning and inspection can affect braking performance.
- Misaligned adjuster screws: Results in uneven wear and inefficiency.
- Improper tools: Using the wrong tools can damage adjusters and complicate future work.
Avoid these mistakes to ensure effective and safe braking.
When Should I Replace Rather Than Adjust?
Recognizing the balance between adjustment and replacement is crucial for maintaining your BMW’s braking efficiency. You should replace the brake shoes if they’re worn down to less than 1/16 of an inch, as adjustments won’t suffice.
Excessive pedal travel or spongy feel might indicate worn components or leaks, necessitating replacement. If the rear drum shows scoring or a significant lip, replacing it will ensure effective contact. Uneven shoe wear can signal malfunctioning parts.
| Scenario | Action Needed | Why? |
|---|---|---|
| Brake shoes < 1/16 inch | Replace shoes | Shoes are too worn for adjustment |
| Excessive pedal travel | Replace parts | Potential underlying issues |
| Scored or lipped drum | Replace drum | Ensures effective braking contact |
| Uneven shoe wear | Inspect/Replace | Indicates possible component issues |
| Fluid leaks/spongy pedal | Replace parts | Suggests deeper mechanical problems |
People Also Ask
How often should BMW drum brakes be adjusted?
You should adjust the drum brakes on your BMW every 6,000 to 10,000 miles for best performance.
If you drive in heavy traffic or carry heavy loads, check them more often.
Regular checks help keep your brakes working well and your car safe.
Can I adjust drum brakes without removing the wheel?
Yes, you can adjust drum brakes without removing the wheel.
Look for the adjuster through the hole in the backing plate. Use a screwdriver to turn the star wheel for adjustments.
Make sure the parking brake is off and check the brakes after each turn.
What causes BMW drum brakes to need frequent adjustment?
BMW drum brakes need frequent adjustment mainly because the brake shoes wear down over time, causing less contact with the drum.
Rust and wrong installation can also lead to problems.
Using the parking brake a lot without adjustments makes the shoes wear faster too.
Regular checks help keep brakes working well.
How much does professional BMW drum brake adjustment cost?
The cost for a professional BMW drum brake adjustment is usually between $100 and $200.
This price can change based on the shop’s rates and if any parts need to be replaced.
It’s a good idea to get quotes from different service centers.
Wrapping Up
To keep your BMW’s rear drum brakes in top shape, adjust them regularly for optimal performance and safety. Proper adjustment ensures effective braking and prevents uneven wear. Use the right tools, follow safety protocols, and pay attention to symptoms of poor adjustment like noise or reduced braking efficiency. If adjustments don’t solve issues, consider replacing components. This maintenance not only extends the life of your brakes but also ensures your vehicle remains reliable and safe on the road.