How to troubleshoot a parking brake or emergency brake that won't hold the car

The emergency brakes will not hold the vehicle if the parking brake level is stuck, the parking brake cable is stretched, or the brake pads or pads are worn.

The parking brake is designed to hold the vehicle in place when it is at rest. If the parking brake does not hold the vehicle, the vehicle may roll over or even damage the transmission if it is automatic.

Most cars have disc brakes at the front and drum brakes at the rear. Rear brakes usually do two things: stop the car and keep it stationary. If the rear brake pads are so worn that they cannot stop the vehicle, the parking brake will not hold the vehicle at rest.

Vehicles can be equipped with rear drum brakes that stop and act as a parking brake, rear disc brakes with integrated parking brakes, or rear disc brakes with drum brakes for the parking brake.

If the parking brakes do not hold the vehicle, check the following:

• Parking brake lever/pedal misadjusted or stuck
• Parking brake cable stretched
• Worn rear brake pads/pads

Part 1 of 3: Diagnosing Parking Lever or Pedal for Adjustment or Stuck

Preparing the vehicle for testing the parking brake lever or pedal

Necessary materials

• Channel locks
• flashlight
• Safety glasses
• Wheel chocks

Step 1: Park your vehicle on a level, firm surface.. Make sure the transmission is in park (for automatic transmission) or in first gear (for manual transmission).

Step 2: Install wheel chocks around the rear wheels, which will remain on the ground. Apply the parking brake to block the rear wheels from moving.

Checking the condition of the parking brake lever or pedal

Step 1: Put on safety goggles and take a flashlight. Locate the parking brake lever or pedal.

Step 2: Check if the lever or pedal is stuck. If the lever or pedal is frozen in place, it could be due to rust at the pivot points or broken pins.

Step 3: Back of the lever or pedal to attach the parking brake cable. Check if the cable is broken or worn. If you have a cable with a bolt attached, check to see if the nut is loose.

Step 4: Try installing and resetting the parking lever or pedal. Check the tension when applying the parking brake. Also check if there is a regulator on the lever. If there is, check if it can be rotated. If the lever adjuster cannot be turned by hand, you can put a pair of channel locks on the adjuster and try to release it. Sometimes, over time, the regulator becomes rusty and the threads freeze.

Cleaning after diagnosis

Step 1: Gather all the tools and get them out of the way. Remove the wheel chocks from the rear wheels and set them aside.

If you need to repair a parking brake lever or pedal that is out of adjustment or stuck, see a professional mechanic.

Part 2 of 3: Diagnosing the parking brake cable if it is stretched

Preparing the vehicle for the parking brake cable test

Necessary materials

• flashlight
• socket
• Jack stands
• Safety glasses
• Wheel chocks

Step 1: Park your vehicle on a level, firm surface.. Make sure the transmission is in park (for automatic transmission) or in first gear (for manual transmission).

Step 2: Install wheel chocks around the rear wheels, which will remain on the ground. Apply the parking brake to block the rear wheels from moving.

Step 3: Raise the car. Using a jack recommended for the weight of the vehicle, raise it under the vehicle at the indicated jack points until the wheels are completely off the ground.

Step 4: Install the jack stands. The jack stands should be located under the jacking points. Then lower the car onto the jacks. For most modern cars, the jack stand attachment points are on a weld right under the doors along the bottom of the car.

Checking the condition of the parking brake cable

Step 1: Put on safety goggles and take a flashlight. Locate the parking brake cable in the cab of the car.

Step 2: Check if the cable is taut. If you have a cable with a bolt attached, check to see if the nut is loose.

Step 3: Go under the car and check the cable along the undercarriage of the car. Use a flashlight and check if there are any fasteners on the cable that are loose or come off.

Step 4: Look at the Connections. Inspect the connections to see where the parking brake cable attaches to the rear brakes. Check to see if the cable is tight at the attachment point to the rear brakes.

Lowering the car after diagnosis

Step 1: Gather all the tools and vines and get them out of the way.

Step 2: Raise the car. Using a jack recommended for the weight of the vehicle, raise it under the vehicle at the indicated jack points until the wheels are completely off the ground.

Step 3: Remove the jack stands and keep them away from the vehicle.

Step 4: Lower the car so that all four wheels are on the ground. Pull out the jack and set it aside.

Step 5: Remove the wheel chocks from the rear wheels and set them aside.

If necessary, have the parking brake cable replaced by a professional mechanic.

Part 3 of 3. Diagnosing the Condition of the Parking Brake Pads or Pads

Preparing the Vehicle for Checking the Parking Brake Pads or Pads

Necessary materials

• flashlight
• Flat head screwdriver
• socket
• Jack stands
• SAE/metric socket set
• SAE wrench set/metric
• Safety glasses
• Sledgehammer 10 pounds
• Tire iron
• Wrench
• Wheel chocks

Step 1: Park your vehicle on a level, firm surface.. Make sure the transmission is in park (for automatic transmission) or in first gear (for manual transmission).

Step 2: Install wheel chocks around the rear wheels, which will remain on the ground. Apply the parking brake to block the rear wheels from moving.

Step 3: Using a pry bar, loosen the nuts on the rear wheels.

• Attention: Do not remove the lug nuts until the wheels are off the ground

Step 4: Raise the car. Using a jack recommended for the weight of the vehicle, raise it under the vehicle at the indicated jack points until the wheels are completely off the ground.

Step 5: Install the jack stands. The jack stands should be located under the jacking points. Then lower the car onto the jacks. For most modern cars, the jack stand attachment points are on a weld right under the doors along the bottom of the car.

Checking the condition of the parking brake pads or pads

Step 1: Put on safety goggles and take a flashlight. Go to the rear wheels and remove the nuts. Remove rear wheels.

• AttentionA: If your car has a hub cap, you need to remove it first before removing the wheels. Most hub caps can be removed with a large flathead screwdriver, while others must be removed with a pry bar.

Step 2: If your car has drum brakes, get a sledgehammer. Hit the side of the drum to free it from the wheel studs and centering hub.

• A warning: Do not hit the wheel studs. If you do, you will need to replace the damaged wheel studs, which can take some time.

Step 3: Remove drums. If you can't remove the drums, you may need a large screwdriver to loosen the rear brake pads.

• Attention: Do not pry the drums to avoid damaging the base plate.

Step 4: With the drums removed, check the condition of the rear brake pads. If the brake pads are broken, you will need to take repair steps at this point. If the brake pads are worn, but there are still pads left to help stop the car, take a tape measure and measure how many pads are left. The minimum number of overlays must not be thinner than 2.5 millimeters or 1/16 inch.

If you have rear disc brakes, then you will need to remove the wheels and check the pads for wear. Pads cannot be thinner than 2.5 millimeters or 1/16 inch. If you have disc rear brakes but have a drum parking brake, you will need to remove the disc brakes and rotor. Some rotors have hubs, so you will need to remove the hub lock nut or the cotter pin and locknut to remove the hub. When you've finished inspecting the drum brakes, you can reinstall the rotor and assemble the rear disc brakes.

• Attention: Once you have the rotor removed and have the hub in it, you will need to check the bearings for wear and condition and it is recommended to replace the wheel seal before installing the rotor back on the vehicle.

Step 5: When you have finished diagnosing the car, if you plan to work on the rear brakes later, you will need to put the drums back on. Adjust the brake pads further if you have to move them back. Put on the drum and wheel. Put on the nuts and tighten them with a pry bar.

• A warning: Do not attempt to drive the vehicle if the rear brakes are not working properly. If the brake linings or pads are below the threshold, then the car will not be able to stop in time.

Lowering the car after diagnosis

Step 1: Gather all the tools and creepers and get them out of the way.

Step 2: Raise the car. Using a jack recommended for the weight of the vehicle, raise it under the vehicle at the indicated jack points until the wheels are completely off the ground.

Step 3: Remove the jack stands and keep them away from the vehicle.

Step 4: Lower the car so that all four wheels are on the ground. Pull out the jack and set it aside.

Step 5: Take a torque wrench and tighten the lug nuts. Make sure you use a star pattern to make sure the wheels are tightened properly without a wobble or wobble effect. Put on a cap. Make sure the valve stem is visible and not touching the cap.

Wheel Nut Torque Values

• 4-cylinder and V6 vehicles 80 to 90 lb-ft
• V8 engines on cars and vans weighing 90 to 110 feet.
• Large vans, trucks and trailers from 100 to 120 ft lbs
• Single Ton and 3/4 Ton Vehicles 120 to 135 ft.lbs

Step 5: Remove the wheel chocks from the rear wheels and set them aside.

Replace the parking brake pads if they fail.

Fixing a parking brake that doesn't work can help improve your vehicle's braking performance and prevent damage to your brake system and transmission.