proportional valve

How do you adjust a proportional valve?


These valves are designed to apply a control pressure on the rear brakes of rear wheel-driven vehicles. There are many different electronic flow control valves that are mostly used in the conversion from drum to disc brakes and in other brake systems. Some of them work by collaborating with the brake master cylinder and some work independently. After the creation of front wheel-driven vehicles, these proportional flow valves become more useful. Generally, they are part of a brake system that controls the amount of pressure applied to the rear brakes. It helps the rear brakes to prevent wheel locking and stops your vehicle safely.

Appropriate Adjustment:

For adjusting the proportional flow valve you should increase the preload gradually on the spring that presses the piston. More preload allows more pressure to flow before the closure of the valve. Oppositely, by decreasing the spring preload, low pressure will pass through the electronic pneumatic flow control valve and will lower the speed of the vehicle.

Considering the safety, you must start with the proportional flow control valve settings by choosing the reduction setting. For testing, find an assistant and an empty parking lot. So you can easily test the working of the valve and do the precise testing of the brakes.

Guidelines to correctly adjust the electronic flow valve

Here are some guidelines to correctly adjust the electronic flow valve:

  • First of all, check that the tires have the recommended pressures.
  • To get the best results, you should have half of a fuel tank, no passengers, and a minimum load in the trunk of your vehicle.
  • Run your car at the speed of 30 MPH and stop it instantly hard enough to lock the wheels.
  • Ask the assistant whether the wheels were locked fully or not.
  • If only the front wheels were locked then adjust the proportional flow valve in two full turns to allow more pressure to the rear brakes and perform the test again.
  • After seeing the results, keep adjusting it until the front and rear wheels start locking up in a hard stop.
  • Keep doing that and test again and again until you achieve the maximum braking.
  • When you achieve that then test the braking at the speed of 50 MPH to determine the effects of a dramatic weight transfer and make the adjustment accordingly if required.

When you are bleeding the brakes, then you must open the proportional flow valve to make the bleeding process easier. Note down the rotations you have made to manage the pressure and after that adjust back out the same rotations to finish the bleeding process.

Final Words:

Remember that until your brake system has the proper level of fluid force and the air is out then the brakes of your vehicles will work properly. If the air is let into, fluid is low or the applied force is low and the proportional flow valves fail then the brakes will not engage so you must have the hand brake to stop the vehicle in the case of an emergency.