GM 10289556
Pressure Metering Valve

Begin the repair work on Brake Proportioning and Combination Valve with correct suspension of the vehicle during lift-up. You should remove all dirt and foreign materials both from the brake pipes and from the proportioning valve before starting service. Untwist the brake pipes from the proportioning valve through back up wrench usage before you remove the valve itself. After returning the valve to its spot, attach brake pipes to the valve with a back up wrench. Tighten Proportioning Valve Tube Nut to 15 Nm (11 ft. lbs.) for installation. End the process by putting down the vehicle before performing brake servicing steps.

Take off all components from the master cylinder reservoir by first pulling out the proportioning valve caps followed by removing the O-rings, springs, and valve pistons. Protect the piston stems from damage by using needle nose pliers. Check if the piston seals need replacement after removing them from the pistons. Also inspect and replace damaged or corroded pistons. Use only alcohol and blow dry components with air that lacks lubricant. Before installing parts you must apply silicone grease from the kit to the O-rings , proportioning valve seals , and proportioning valve piston stems . Put new seals onto the proportioning valve pistons and set them in the correct position with the lip seals facing up toward the caps. Replace all components inside the master cylinder. Put new O-rings into the caps' grooves of the proportioning valve and fit the caps onto the master cylinder while torqueing them to 27 Nm (20 ft. lbs.). Bleed the brakes and put back the master cylinder reservoir to finish the job.

Tighten the proportioning valve caps to 27 Nm (20 ft. lbs.).

Remove the proportioning valve seals from the pistons and inspect the pistons for corrosion and deformation, replacing them if necessary.

First, raise and suitably support the vehicle.