How Do Brake Systems Work in Subaru Vehicles?

How Do Brake Systems Work in Subaru Vehicles?
Thursday, 19 April, 2012

How Do Brake Systems Work in Subaru
| How Does Subaru’s Brake Assist
System Work? | What Are Some Good Braking Tips?

How Do Brake Systems Work in Subaru Vehicles?

All these questions and more are
answered in today’s lesson:

Schmecnical Lesson 1: Subaru Brake Systems

Have you ever wondered how your brake system functions ? Or possibly you have never picked up that owner ‘s manual and read it cover to cover to in full understand your vehicle. Well, wonder no more ! We are here to present some of the more technical aspects of vehicles and their function and operation. Introducing our new web log series “ technical Schmecnical ” will be an ongoing serial and serves as a helpful lead and resource for vehicle owners to better understand their vehicles. All of our information comes from owners manuals, quick reference book guides, technical manuals, and tied our technicians themselves !

Braking Tips:

  • WARNING! Never rest your animal foot on the brake pedal while driving ! This can cause dangerous overheating of the brakes and needle wear on the brake pads and linings.
  • When the Brakes Get Wet: When drive in the rain or after washing the vehicle, the brake pads may get wet. As a leave, brake stopping distances will be farseeing. To dry the brakes, drive the fomite at a safe accelerate while lightly depressing the brake pedal to heat up the brakes.
  • Use of Engine Braking: Remember to make practice of locomotive brake in addition to foot brake. When descending a grade, if only the foot brake is used, the brakes may start working improperly because of brake fluid overheating, caused by overheat brake pads. To help prevent this, shift into a lower gearing to get stronger engine brake.
  • Braking When a Tire is
    Do not depress the brake bicycle on the spur of the moment when a tire is punctured. This could cause a loss of manipulate of the fomite. Keep driving straight ahead while gradually reducing amphetamine. then lento pull off the road to a safe station .

Subaru Brake System:

  • Two Separate Circuits: Your fomite has two freestanding lap brake systems. Each circumference works diagonally across the fomite. If one racing circuit of the bracken system should fail, the early one-half of the arrangement calm works. If one circuit fails, the brake pedal point will go down much closer to the floor than usual and you will need to press it down much heavily. And a much longer outdistance will be needed to stop the fomite.
    • Brake Booster:

      The brake booster uses engine manifold vacuum to assist braking
      force. Do not turn off the engine while driving because that will
      turn off the brake booster, resulting in poor braking power.

      The brakes will continue to work even when the brake booster
      completely stops functioning. If this happens, however, you will
      have to depress the pedal much harder than normal and increase
      braking distance will increase.

    Brake Assist System:WARNING! Do not be cocksure about the brake help. It is not a organization that brings more brake ability to the vehicle beyond its brake capability. Always use the extreme caution when driving regarding vehicle amphetamine and safe outdistance.

    When you need to brake abruptly, continue depressing the brake pedal strongly to bring the effect of the brake aid.

    • Brake serve

      is a driver assistance system. It assists the brake power when the
      driver cannot depress the brake strongly and the brake power is
      insufficient. Brake Assist generates the brake power according to
      the speed at which the driver depresses the brake pedal.

  • Note: When you depress the brake pedal powerfully or on the spur of the moment, the comply phenomenon happen. however, tied though these occur, they do not indicate any malfunctions, and the bracken aid system is operating by rights :
    • You might feel that the brake pedal is applied by lighter force and generates a greater braking effect .
    • You might hear an ABS operating noise from the engine compartment .

Anti-Lock Brake
System (ABS)
How Do Brake Systems Work in Subaru Vehicles?

The ABS system prevents the lock-up of wheels which may occur during sudden brake or braking on slippery road surfaces. This helps prevent the loss of steering restraint and directional stability caused by bicycle lock-up .
When the ABS system is operating, you may hear a chatter noise or feel a flimsy shaking in the bracken pedal point. This is normal when the ABS operates. The ABS system will not operate when the vehicle travel rapidly is below approximately 6 miles per hour ( 10 kilometers per hour )
WARNING! Always use the extreme concern in driving-overconfidence because you are driving a vehicle with the ABS system could well lead to a serious accident !
Caution! The ABS system does not always decrease stopping distance. You should always maintain a condom following distance from other vehicles .

  • When driving on badly surfaced roads, perplex roads, frigid roads, or over deep newly fallen snow, stopping distances may be longer for a vehicle with the ABS system than one without. When driving under these conditions, therefore, reduce your amphetamine and leave ample distance from other vehicles.

    **Just because you drive a Subaru does not make you invincible ! Use common sense, drive at a condom speed, and do not put others in damage ‘s way by driving aggressively !

  • When run down chains are installed, stopping distances may be longer for a fomite with the ABS system than one without. Be certain to reduce your rush and maintain a safe distance from the vehicle in front man .
  • When you feel the ABS system engage, you should maintain constant brake pedal blackmail. Do not pump the brake pedal since doing therefore may defeat the operation of the ABS system .

ABS System Self

just after the fomite is started, you may feel on the brake pedal a vibration exchangeable to when the ABS operates, and you may besides hear the sound of the ABS working from the engine compartment. This is caused by an automatic functional test of the ABS system being carried out and does not indicate any abnormal condition .

Brake Force Distribution (EBD System):

  • The EBD system maximizes the potency of the brakes by allowing the rear brakes to supply a greater proportion of the braking military unit. It functions by adjusting the distribution of braking force to the rear wheels in accord with the vehicle ‘s load condition and focal ratio.
  • The EBD system is an built-in contribution of the ABS system and uses some of the ABS system ‘s components to perform its affair of optimizing the distribution of braking force. If any of the ABS components used by the EBD system malfunction, the EBD arrangement besides stops working.
  • When the EBD system is operating, you may hear a chatter noise or feel a slight vibration in the brake bicycle. This is convention and does NOT indicate a malfunction .

What to Do if the
EBD System Malfunctions:

  • If a malfunction occurs in the EBD system, the arrangement stops working and the bracken system warning light and ABS warning light illuminate simultaneously .
  • The EBD system may be malfunctioning if the brake system warning system light and the ABS warn light up illuminate simultaneously while driving .
  • even if the EBD system malfunctions, the conventional brake system will still function. however, the rear wheels will be more prone to locking when the brakes are applied harder than usual and the vehicle ‘s apparent motion may therefore become reasonably harder to control .
  • If the brake arrangement warning light and ABS warning easy light simultaneously, take the follow steps :
  1. Stop the vehicle in the nearest safe, flat location .
  2. Shut down the locomotive, apply the park brake, and then restart it .
  3. Release the parking brake. If both warning lights turn off, the EBD system may be malfunctioning. Drive cautiously to the nearest SUBARU dealer and have the system inspected .
  4. If both warning lights light again and remain illuminated after the engine has been restarted, shut down the engine again, apply the parking brake, and check the brake fluid level .
  5. If the bracken fluid level is not below the “ MIN ” target, the EBD system may be malfunctioning. Drive cautiously to the nearest SUBARU dealer and have the system inspected .
  6. If the brake fluent is below the “ MIN ” score, DO NOT drive the vehicle ! alternatively, have the vehicle towed to the nearest SUBARU principal for repair .


  • Driving with
    the brake system warning light illuminated is dangerous. This
    indicates your brake system may not be working properly. If the
    light remains illuminated, have the brakes inspected by a SUBARU
    dealer immediately.
  • If at all in doubt about whether the brakes are operating by rights, do not drive the vehicle. Have your vehicle towed to the nearest SUBARU principal for repair.

How Do Brake Systems Work in Subaru Vehicles?
Brake Override
System (BOS)

The brake override organization ( BOS ) is an active safety feature first introduced on all 2012 Impreza 2.0i models and will be standard equipment on ALL 2013 Subaru vehicles, starting with the newfangled 2013 BRZ. The BOS can help prevent claims of unintentional vehicle acceleration because it monitors the coincident application of both the bracken pedal point and the accelerator pedal point by the driver while the vehicle is moving. here are the key features of the system :
Override System Features:

  • System Activation Delay- The system has built-in activation delay which senses the accidental depression of both the brake bicycle and the accelerator pedal. This energizing check allows the driver to realize that both pedals are being depressed simultaneously. If both the brake and accelerator pedals are immediately released by the driver, the system will not activate. If both pedals are not immediately released, the system will activate .
  • System Activation– The system activates when BOTH the brake bicycle and accelerator pedal point are applied. On initial activation, the system is time-delayed until the ABS control unit raises the brake fluent press to a specific charge to control vehicle bowel movement. Engine operation is reduced by the closure the choke plate. physical application of the catalyst pedal point by the driver has virtually little or not effect on engine or vehicle travel rapidly .
  • Dual
    Stage Activation
    • Light brake pedal point application-The system will take longer to activate when both the accelerator pedal point is depressed and the brake pedal point is lightly depressed. This delay activation allows the driver to apply the brake concisely and hush maintain accelerator bicycle restraint .
    • Heavy brake pedal point application -The organization will immediately activate when both the accelerator and the brake pedal are depressed.
  • Deactivation–
    The system deactivates when it senses only INDIVIDUAL operation of the brake pedal or the catalyst pedal point. During deactivation, brake fluid imperativeness is released and the choke home plate is momentarily activated to maintain drivetrain pressure. The system positions the accelerator plate above baseless to operation to prevent the vehicle from lunging forward. The system then synchronizes the linear operation of the restrict plate and accelerator pedal for convention vehicle operation .

Read more about the Subaru Brake Override System here.

As constantly, please use caution and common sense while operating your vehicle. Do not become then cocksure in your fomite abilities that you forget the fundamentals like keeping a dependable outdistance from other vehicles, maintaining the rush limit, and paying care to your vehicle, its warning lights, and please please please remember that servicing your vehicle every 3,000 miles is important to keep your vehicle running smoothly. Do not underestimate the importance of oil changes, submit inspections, and vehicle guard checks, such as Stanley Subaru ‘s 27-Point Inspection. If you have questions, please contact our Service Department by calling 800-439-8989 or by emailing our Service Manager .
Have a question or subject suggestion you would like us to cover ? Let us know in the comments below and we will do the research and get it covered for you !
Have a great day and glad reading !

[Update: read more about the brake warning lights, what they mean, and what you have to do about them in our Dashboard Lights Deep Dive.]

Have more questions? Need to know what other stuff means? Check out the Technical Schmecnical tag or try our FAQ.

source :
Category : Car Brakes