A proportioning valve is used to reduce the hydraulic pressure to the rear brakes because of weight transfer during high speed stops. This helps to keep the rear brakes from locking up by improving front-to-rear brake balance.
On 1970-71 Crown models, the proportioning valve is attached to the side frame side rail, about halfway between the front and rear wheels. On all other models, it is located in the engine compartment, near the master cylinder.
REMOVAL & INSTALLATION
- Disconnect the brake lines from the valve unions.
- Unfasten the valve mounting bolt, if used.
- Remove the proportioning valve assembly.
If the proportioning valve is defective, it must be replaced as an assembly. It cannot be rebuilt.
- Installation is the reverse of removal. Bleed the brake system after it is completed.