GM 18014469
Pressure Metering Valve

Washing the proportioning valve is forbidden because its internal components arrive with specific grease already in place. Start the repair by removing both the bracket from the master cylinder followed by the master cylinder reservoir. Use needle nose pliers to remove proportioning valve caps together with O-rings , springs , and proportioning valve pistons while making sure to protect the piston stems. Check the pistons for signs of corrosion and deformation before changing any damaged parts. Use clean denatured alcohol to sanitize all pieces then use non-lubricated compressed air for drying. When replacing the components use the silicone grease from the repair kit to lubricate the O-rings together with proportioning valve seals and proportioning valve piston stems. Install the new proportioning valve piston seals by positioning the lip seals upward and install the components into the master cylinder body. Position the springs inside the master cylinder body while placing new O-rings in the proportioning valve cap grooves. Tighten the proportioning valve caps to 27 Nm (20 ft. lbs.) torque specification.Replace the bracket to both the master cylinder and the master cylinder reservoir afterward. Finally, bleed the brakes.

To remove the proportioning valve instead, first, do not clean the part in any cleaning preparation since its components are pre-lubricated with a special grease. First, doff the bracket from the master cylinder, master cylinder reservoir next. Then remove the proportioning valve caps, O-rings, and springs, after which remove the proportioning valve pistons with the use of needle nose pliers not to damage the piston stems. Replace the piston seals (proportioning valve seals) from the pistons and look for corrosion and deformation of the pistons, replacing them as required. Treat all the parts with clean denatured alcohol and dry then with a non-lubricated compressed air. During installation, lubricate the O-rings and the proportioning valve seals, and piston stems with the silicone grease that is included in the repair kit. Set new seals to the proportioning valve pistons with the lips facing up towards the cap and re-install pistons and seals into the master cylinder body. Mount the springs and new O-rings into the grooves of the proportioning valve caps, then tighten caps to 27 Nm (20 ft. lbs). Finally, reattach the bracket and the master cylinder reservoir, and then proceed with bleeding of the brakes.

Lubricate the O-rings, proportioning valve seals, and proportioning valve piston stems with the silicone grease supplied in the repair kit.

Connect the brake pipe fittings to the proportioning valve with a backup wrench.

Remove the master cylinder reservoir.