Specific test equipment is required to check the operation and adjustment of the regulator.
If replaced, the adjustment of the regulator should be verified by a certified technician using approved equipment. Improper adjustment of the regulator will affect the vehicle's stability under braking.
- Disconnect the negative battery cable. Remove the hydraulic fluid from the master cylinder with a syringe or hose used only with clean brake fluid.
- Note the location of the tensioning spring bracket and matchmark, then remove the spring.
- Using paint, matchmark the brake lines to the pressure regulator.
- Using a flare nut wrench to loosen, disconnect the brake lines from the proportioning valve.
- Installation is in reverse order of removal noting the following:
- Bleed the brake system, and then check the brake pressure. Attach a set of brake pressure gauges such as VAG 1310 to the left front and right rear brake assemblies and check the vehicle in an unladen (full tank of fuel, spare tire, tool kit and jack) ready-to-drive state.
Do NOT adjust the pressure regulator spring with the brake pedal pressed down.
- Note the following:
- If the rear pressure is too high, loosen the tension on the regulator spring
- If the rear pressure is too low, increase the tension on the regulator spring
- Once the regulator is properly adjusted, remove the gauges and bleed the brakes.