This document provides guidance on bleeding the brakes of a 120 series Toyota Prado and addresses common concerns regarding brake pedal feel.
Problem
The vehicle owner was concerned about the proper brake bleeding procedure for a 120 series Prado, as a workshop manual suggested an unconventional method involving brake line clamps and bleeding the master cylinder first. They also observed a soft brake pedal that slowly sinks to the floor when stationary.
Solution
- Standard Bleeding Procedure: Bleed the brakes as you would with most vehicles. Start with the wheel furthest from the master cylinder and work your way closer.
- Maintain Fluid Level: During the bleeding process, ensure the brake fluid reservoir is consistently topped up with the correct DOT specified brake fluid to prevent air from entering the system.
- Load Sensing Proportioning Valve (LSPV): Only early 120 GX models without ABS have a Load Sensing Proportioning Valve (LSPV) that needs to be bled after the wheels. Models with ABS have Electronic Brake Force Distribution (EBD).
Brake Pedal Feel Troubleshooting
- Soft Pedal: The Prado is known to have a relatively soft brake pedal compared to other vehicles.
- Pedal Sinking to Floor: A brake pedal that slowly sinks to the floor when stationary is not normal and indicates a potential issue.
- Possible Causes:
- Internal Leak: An internal leak within the braking system could be the cause.
- Defective Master Cylinder: The master cylinder might be faulty.
- Recall: There may have been a recall related to a seal issue in the master cylinder on certain years/models. Check vehicle history.
Relevant Parts
- DOT Specified Brake Fluid: Use the correct DOT specified brake fluid. Do not use old or unknown brake fluid.
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