1. Check the Cable System:
* Visual Inspection: Start by looking at the parking brake cable(s) running from the lever under the dash to the rear brakes. Check for:
* Corrosion: Look for rust or significant wear on the cable housing. Corrosion can cause the cable to bind or fray.
* Kinks or Breaks: Inspect for any bends, kinks, or obvious breaks in the cable.
* Loose Connections: Ensure the cable is properly connected at both ends (lever and rear brakes). Look for any loose or damaged brackets holding the cable in place.
* Cable Adjustment: Many times, the problem is simply that the cables are too loose. Locate the adjustment mechanism. This is usually a star-shaped wheel or a similar adjuster near the rear brakes. You may need to loosen a retaining nut or clip to adjust. Carefully turn the adjuster to tighten the cable. Test the parking brake after each small adjustment. Be cautious not to overtighten; this can damage the system. It should require a firm pull on the lever to engage.
2. Inspect the Rear Brake Shoes:
* Wear: If the brake shoes are excessively worn, they might not be able to grip the drum effectively, even with a properly adjusted cable. Inspect the shoes for wear. If worn excessively, they'll need replacement.
* Contamination: Grease, oil, or other contaminants on the brake shoes can significantly reduce their effectiveness. Clean them with a brake parts cleaner.
3. Check the Parking Brake Lever Mechanism:
* Internal Issues: Sometimes the problem lies within the parking brake lever mechanism itself. This is less common but possible. If the lever feels loose or doesn't engage firmly, there may be an internal problem requiring further inspection (often requiring removal of the center console).
4. Additional Considerations:
* Return Spring: The parking brake should have a spring to return it to the disengaged position. A broken spring could prevent it from fully disengaging or contribute to its inability to stay engaged.
* Emergency Brake Release: There is usually a cable or mechanism to release a completely jammed parking brake. If completely jammed, consult your owner's manual for the location and operation of the emergency release.
Repair Steps (General):
1. Safety First: Always use jack stands when working under your vehicle. Never rely solely on a jack.
2. Gather Tools: You'll need basic tools (wrenches, sockets, pliers), brake cleaner, possibly a cable lubricant, and possibly new brake shoes (depending on your inspection).
3. Follow a Repair Manual: A repair manual specific to your 2001 Chevy Blazer 4WD is highly recommended. This will provide detailed diagrams and instructions. You can often find these online (e.g., Haynes or Chilton manuals).
4. Take Your Time: Working on brakes is crucial for safety. Don't rush, and if you're unsure about any step, consult a professional mechanic.
If you are not comfortable working on your brakes yourself, it's best to take your Blazer to a qualified mechanic. A poorly adjusted or repaired parking brake can be a significant safety hazard.
