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Was changing out my power steering fluid the other day and was thinking about the Gen5's that have electric PS. Would braking eventually go this way? Why or why not?

My guess for not is that if you had an electrical failure at some point, you'd lose braking - which is not good. Perhaps you'd need a mechanical-style emergency brake then if this worst-case scenario happened.
 

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Was changing out my power steering fluid the other day and was thinking about the Gen5's that have electric PS. Would braking eventually go this way? Why or why not?

My guess for not is that if you had an electrical failure at some point, you'd lose braking - which is not good. Perhaps you'd need a mechanical-style emergency brake then if this worst-case scenario happened.
Electric brakes already exist. Their characteristics are known... and cars still have hydraulic brakes. The system engineering is safe, the parts are cheap, the mechanics are trained, glycol is neither rare nor dangerous, and they already passed several major opportunities to redo the whole system without using them. There was the shift away from organic linings, then the shift from pure hydraulic to electric override hydraulic (ABS) and they still kept what they've got now. It works.
 

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Your 2011 Subaru ALREADY has a form of 'electric braking'. The ABS pump has the ability to apply the brakes to ANY wheel individually. This is part of the EBD system (Electronic Brake Distribution)

Also, the AWD system is tied into the 'electric braking' thru the ABS pump. While accelerating, any wheel which looses traction will be detected by the ABS system and the brake on that wheel will be applied. This sends the torque to the other three wheels.

Some Subies also use the 'electric braking' to apply the brake to the inside-front wheel as you enter corners. This effectively helps the vehicle pull itself around the corner.

Additionally, the 'electric braking' is used to help the vehicle recover from a skid by using sensors to detect sideways movement and apply the brakes to the appropriate wheels.

After reading the above, I hope you can see that the engineers have already taken advantage of the ABS pump ability to apply brake on any wheel by adding some yaw-sensors and monitoring the wheelspeed sensors.
 

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2007 2.5 L Obsidian Black Outback XTL
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If it was to follow standard industrial automation control strategies then braking would be one of those "fail safe" designs where a failure of the system actually releases something holding the brakes open.

When you start your car and after the computer checks off on a bunch of things being good, then the brakes would be permissively allowed to disengage. If something fails, like power, then the holdback mechanism stops working and the brakes are applied, bringing you to a stop and immobilizing the vehicle.
 

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This is how vehicles with air brakes work.

If it was to follow standard industrial automation control strategies then braking would be one of those "fail safe" designs where a failure of the system actually releases something holding the brakes open.

When you start your car and after the computer checks off on a bunch of things being good, then the brakes would be permissively allowed to disengage. If something fails, like power, then the holdback mechanism stops working and the brakes are applied, bringing you to a stop and immobilizing the vehicle.
 
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