What happens when the proportioning valve goes bad?
Rear wheels lock up. Since the proportioning valve decreases the pressure sent to the rear brakes, the main symptom the valve is going bad is the rear wheels locking up when the brakes are applied. Furthermore, the wheels will lock up more easily on wet surfaces. The rear brakes may feel touchy when applied even gently.
Where is the proportioning valve in a car?
The proportioning valve, also called the combination valve, is located in the disc braking system. It is responsible for controlling the braking pressure between the front and rear brakes. Equal brake force cannot be applied to all of the wheels on the car at the same time because the rear wheels will lock up.
How to deal with a bad proportioning combination?
Find an empty parking lot and have someone come with you so they can watch the back brakes. With the person safely away from the vehicle, drive the car and make a few medium to hard stops. Make sure to press the brake several times to simulate an emergency stop.
How do you get a proportioning valve to work?
Bleed the rear brake line again at the proportioning valve, as you did before if you still have a brake dash light. Bleed the front brake lines on the proportioning valve in the same fashion. This reversal of pressure will eventually break the spool loose inside the proportioning valve, equalizing the pressure between the front and rear brakes.
What kind of proportioning valve does Wilwood use?
Wilwood’s new Combination Proportioning Valve substantially simplifies mounting, plumbing, wiring and brake proportioning adjustments on vehicles with custom brake systems.
What are the symptoms of a bad proportioning valve?
If you suspect there is an issue with your proportioning valve, check for the following symptom: Rear wheels lock up Since the proportioning valve decreases the pressure sent to the rear brakes, the main symptom the valve is going bad is the rear wheels locking up when the brakes are applied.
How do you get a proportioning valve unstuck?
Apply the emergency brake and lift the hood. Unscrew, or unsnap the master cylinder cap and fill the master cylinder with brake fluid to the top limit line. Leave the cap off. Use a floor jack to raise the vehicle at the front end and place two jack stands under the frame near each wheel.