1994 Chrysler Concorde Brake Release Mechanism Issue

Vehicle: Chrysler Concorde 1994

Owner's Problem Description

The owner reports that the foot brake of their 1994 Chrysler Concorde does not release properly. They have to manually manipulate the toggle plate underneath the vehicle to get it to release. Attempts to lubricate the mechanism have not resolved the issue. The owner is concerned that there might be a missing spring or another component involved in the release mechanism.

Professional Technical Analysis

The 1994 Chrysler Concorde is equipped with a hydraulic brake system that utilizes a foot-operated brake pedal which actuates the brake calipers through a toggle mechanism. The owner describes a situation where the brake pedal does not return to its neutral position unless manually assisted, indicating a potential failure in the release mechanism of the brake system. Given the vehicle's age, it is crucial to consider the wear and tear on components such as the toggle plate, springs, and any associated linkages. The brake system's performance could also be compromised by corrosion or debris in the mechanism that hinders movement. In this case, the toggle plate appears to operate smoothly by hand, which suggests that the issue might lie with internal components or the spring that provides necessary tension for the release. Additionally, any binding in the brake cables or linkage should be inspected as well. Safety concerns are paramount here, as a non-releasing brake could lead to compromised vehicle control during operation.

Possible Causes

Most common causes (ordered by frequency):

  1. Toggle Plate Mechanism Failure: The toggle plate responsible for releasing the brake may have a worn or damaged spring, preventing it from returning to its neutral position. This could be due to corrosion or physical wear, common in vehicles of this age. - Manual manipulation of the toggle plate allows for brake release, indicating potential spring or mechanism failure.
  2. Binding Brake Cables: Brake cables may be binding due to rust or improper routing, preventing the pedal from fully returning. A thorough inspection of the cable condition and routing is necessary to identify any issues. - Visual inspection of brake cables reveals signs of rust or kinks that could impede movement.
  3. Internal Brake Mechanism Corrosion: Internal components of the brake mechanism may have corroded over time, leading to binding or failure of the release mechanism. This is particularly common in older vehicles exposed to moisture. - Signs of corrosion or wear on internal brake components during inspection.

Diagnostic Steps

Professional Diagnosis Process

Follow these systematic steps to accurately diagnose the issue. Each step builds on the previous one to ensure accurate diagnosis.

  1. STEP 1 - Visual Inspection: Begin with a thorough visual inspection of the brake pedal assembly and toggle plate mechanism. Look for any signs of wear, rust, or misalignment in the components. Check for proper routing of the brake cables and any binding points that could prevent free movement.
  2. STEP 2 - Toggle Plate Function Test: Manually operate the toggle plate to assess its movement. If it moves freely by hand but fails to release the brake when stepped on, further investigation of the spring mechanism and internal components is warranted.
  3. STEP 3 - Brake Cable Examination: Inspect the brake cables for any signs of fraying, binding, or rust. Ensure that all connections are secure and that the cables are properly lubricated to prevent sticking during operation.
  4. STEP 4 - Functional Test of the Brake System: After addressing potential issues, perform a functional test of the brake system to ensure proper operation. Monitor the brake pedal response and check for smooth release under normal driving conditions.

Repair Recommendations

CRITICAL PRIORITY - Replace Worn Components: If any components such as the toggle plate spring are found to be worn or damaged, replace them immediately to ensure proper brake function. Use OEM or quality aftermarket parts for reliability. Estimated cost for replacement parts ranges from $50 to $150.

Priority: critical

HIGH PRIORITY - Repair or Replace Brake Cables: If the brake cables are found to be binding or damaged, they should be repaired or replaced as necessary. Ensure that all connections are secure and that cables are routed correctly. Estimated cost for cables ranges from $100 to $200.

Priority: high

MEDIUM PRIORITY - Lubricate Mechanisms: Regular maintenance should include the lubrication of the toggle plate and associated linkages to prevent binding. Use a high-quality silicone or lithium grease to ensure smooth operation. This is a low-cost preventive measure, typically under $20.

Priority: medium

Preventive Tips

  • Regular Brake System Inspections: Schedule regular inspections of the brake system to catch potential issues early. Look for signs of wear on components like the toggle plate and cables, and address them promptly to avoid larger repairs.
  • Lubrication Routine: Implement a routine for lubricating brake components, particularly the toggle plate and linkages, to ensure smooth operation. This should be done at least once a year or during brake service.
  • Monitor Brake Performance: Pay attention to the brake pedal feel and response during driving. Any changes may indicate underlying issues that need to be addressed. Use GeekOBD APP for monitoring system health and error codes.

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