How to test and replace the power brake booster on Subaru Outback?

The power brake booster needs only regular checks of the vacuum hose and case. Test operation by pressing the brake pedal several times with the engine off, ensuring no change in pedal reserve distance. If the pedal lowers slightly when the engine is on, it's functioning correctly. Test air tightness by starting the engine, turning it off after a minute, then pressing the pedal slowly a few times. If the pedal lowers initially but rises after a few presses, the booster is airtight. If defective, replace the booster. Removal involves disconnecting the vacuum hose, removing the master cylinder, disconnecting the booster pushrod clevis, and removing the four booster-to-firewall nuts. Reverse these steps for installation, adjust the pushrod if needed, and bleed the brakes.

Genuine Subaru Outback Brake Booster

Brake Power Booster

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20 Brake Boosters found

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Subaru Outback Vacuum BSTR Assembly LH
Part Number: 26402AL13A
$103.34 MSRP: $149.77
You Save: $46.43 (31%)
Ships in 1-3 Business Days
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Product Specifications
- Other Name: Vac BSTR Assembly Lh
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 2018-2019 Subaru Outback | 2.5i, 2.5i Limited, 2.5i Premium, 2.5i Sport, 2.5i Touring, 3.6R Limited, 3.6R Touring | 2.5L H4, 3.6L H6
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Subaru Outback Vacuum BSTR Assembly LH
Part Number: 26402AL12A
$99.94 MSRP: $144.83
You Save: $44.89 (31%)
Ships in 1-3 Business Days
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Product Specifications
- Other Name: Vac BSTR Assembly Lh
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 2018-2019 Subaru Outback | 2.5i, 2.5i Limited, 2.5i Premium, 2.5i Sport, 3.6R, 3.6R Limited, 3.6R Premium | 2.5L H4, 3.6L H6
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Subaru Outback Vacuum BSTR Assembly LH
Part Number: 26402AJ01A
$282.79 MSRP: $417.10
You Save: $134.31 (33%)
Ships in 1-3 Business Days
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Product Specifications
- Other Name: Vacuum Booster Assembly; Booster Assembly, Brake Booster
- Replaced by: 26402AJ201
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 2010-2014 Subaru Outback | 2.5GT Limited, 2.5GT Premium, 2.5i, 2.5i Limited, 2.5i Premium, 2.5i Sport, 2.5i Touring, 3.6R, 3.6R Limited, 3.6R Premium, 3.6R Touring | 2.5L H4 DOHC, 2.5L H4 SOHC, 2.5L H4 Turbo, 3.6L H6
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Subaru Outback Vac BSTR Assembly LH
Part Number: 26402AN00A
$107.27 MSRP: $155.47
You Save: $48.20 (31%)
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Product Specifications
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 2020-2021 Subaru Outback | 2.4R F/R-O, 2.4R Limited, 2.4R Touring, 2.5i, 2.5i Limited, 2.5i Premium, 2.5i Sport, 2.5i Touring | 2.4L H4 DIT, 2.5L H4 DI
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Subaru Outback Vacuum BSTR Assembly LH
Part Number: 26402AG15A
$355.95 MSRP: $525.00
You Save: $169.05 (33%)
Ships in 1-3 Business Days
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Product Specifications
- Other Name: Vacuum Booster Assembly; Booster Assembly, Brake Booster
- Replaced by: 26402AG260
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 2007-2009 Subaru Outback | 2.5i, 2.5i Base, 2.5i Limited, 3.0R, 3.0R Limited, 3.0R LL-Bean, Base, GT, GT Limited, XT Limited | 2.5L H4, 2.5L H4 Turbo, 3.0L H6
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Subaru Outback Vacuum BSTR Assembly LH
Part Number: 26402AE32A
$121.44 MSRP: $176.00
You Save: $54.56 (31%)
Ships in 1-3 Business Days
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Product Specifications
- Other Name: Vacuum Booster Assembly; Booster Assembly, Brake Booster
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 2002-2004 Subaru Outback | Base, Brighton, Cold Weather, Flat6, Flat6 L.L.Bean, Flat6-S, GT, L, Limited, SUS Flat6, SUS Limited | 2.5L H4, 3.0L H6
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Subaru Outback Vacuum Booster Assembly
Part Number: 26402AJ17A
$282.79 MSRP: $417.10
You Save: $134.31 (33%)
Ships in 1-3 Business Days
ADD TO CART
Product Specifications
- Replaced by: 26402AJ201
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 2012 Subaru Outback | 2.5GT Limited, 2.5i, 2.5i Limited, 2.5i Premium, 3.6R, 3.6R Limited, 3.6R Premium | 2.5L H4 SOHC, 2.5L H4 Turbo, 3.6L H6
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Subaru Outback Gasket Booster
Part Number: 26467AJ00A
Product Specifications
- Other Name: Gasket; Booster Assembly Gasket
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 2010-2017 Subaru Outback | 2.5GT Limited, 2.5GT Premium, 2.5i, 2.5i Limited, 2.5i Premium, 2.5i Sport, 2.5i Touring, 3.6R, 3.6R Limited, 3.6R Premium, 3.6R Touring | 2.5L H4, 2.5L H4 DOHC, 2.5L H4 SOHC, 2.5L H4 Turbo, 3.6L H6
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Subaru Outback Vacuum BSTR Assembly LH
Part Number: 26402AE47A
Product Specifications
- Other Name: Vacuum Booster Assembly; Booster Assembly, Brake Booster
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 2003-2004 Subaru Outback | Baja, Baja-B, Baja-S | 2.5L H4, 2.5L H4 Turbo
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Subaru Outback Vacuum Booster Assembly
Part Number: 26402AC110
Product Specifications
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 1999 Subaru Outback | L | 2.2L H4 Series
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Subaru Outback Vacuum BSTR Assembly LH
Part Number: 26402AE04A
Product Specifications
- Other Name: Vacuum Booster Assembly; Booster Assembly, Brake Booster
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 2000-2001 Subaru Outback | Brighton | 2.5L H4
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Subaru Outback Vacuum BSTR Assembly LH
Part Number: 26402AG04A
Product Specifications
- Other Name: Vacuum Booster Assembly; Brake Booster
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 2005-2006 Subaru Outback | 2.5i, 2.5i Limited | 2.5L H4
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Subaru Outback Vacuum Booster Assembly
Part Number: 26402AE310
Product Specifications
- Other Name: Booster Assembly, Brake Booster
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 2002-2004 Subaru Outback | Flat6, SUS Flat6 | 3.0L H6
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Subaru Outback Vacuum BSTR Assembly LH
Part Number: 26402AG06A
Product Specifications
- Other Name: Vacuum Booster Assembly; Booster Assembly, Brake Booster
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 2005-2006 Subaru Outback | 2.5i, 2.5i Limited, 3.0R, 3.0R Limited, 3.0R LL-Bean, GT, GT Limited | 2.5L H4, 2.5L H4 Turbo, 3.0L H6
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Subaru Outback Vacuum BSTR Assembly LH
Part Number: 26402AE05A
Product Specifications
- Other Name: Vacuum Booster Assembly; Booster Assembly, Brake Booster
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 2000-2001 Subaru Outback | Base, Cold Weather, Flat6, Flat6 L.L.Bean, GT, L, Limited, SUS Limited | 2.5L H4, 3.0L H6
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Subaru Outback Vacuum Booster Assembly
Part Number: 26402FA071
Product Specifications
- Other Name: Brake Booster
- Replaces: 26402FA070
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 1996-1999 Subaru Outback | Brighton, L | 2.2L H4 , 2.2L H4 (New EVAPO), 2.2L H4 Series
View related parts
Subaru Outback Vacuum BSTR Assembly LH
Part Number: 26402AG05A
Product Specifications
- Other Name: Vacuum Booster Assembly; Booster Assembly, Brake Booster
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 2005-2006 Subaru Outback | GT, GT Limited | 2.5L H4 Turbo
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Subaru Outback Master Vacuum Assembly
Part Number: 26402AA236
Product Specifications
- Other Name: Vacuum Booster Assembly; Brake Booster
- Replaces: 26402AA233, 26402AA234, 26402AA230, 26402AA231, 26402AA232, 26402AA235
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 1996-1999 Subaru Outback | GT, L, LS, LS-I, Out Back, SUS | 2.2L H4 , 2.2L H4 (New EVAPO), 2.5L H4
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Subaru Outback Vacuum Booster Assembly
Part Number: 26402FA061
Product Specifications
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 1996-1999 Subaru Outback | Post | 2.2L H4 , 2.2L H4 (New EVAPO), 2.2L H4 Series
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Subaru Outback Vacuum Booster Assembly
Part Number: 26402AE200
Product Specifications
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 2001 Subaru Outback | Flat6 | 3.0L H6

Subaru Outback Brake Booster

Subaru Outback Brake Booster amplifies the brake pedal force to the master cylinder to reduce the effort required to slow or stop the vehicle. Located between the brake pedal and the master cylinder, a Brake Booster multiplies driver effort using a pressure differential, allowing a Subaru driver in any Outback to achieve strong braking with less physical input. This Brake Booster features a vacuum chamber along with a diaphragm and piston inside a two-piece shell. When your Subaru engine provides vacuum to both sides of the diaphragm, brakes stay released. When you press the pedal, a valve opens up atmospheric pressure to the rear half, forcing the piston forward and applying hydraulic pressure. There is also a hydraulic style in the auto field that uses pump-generated fluid pressure for assistance, but the vacuum type is widely noted for reliability. The Brake Booster will continue to assist for only a limited number of stops after an engine stall. Therefore, steady vacuum is vital for every Subaru Outback driver, and the Brake Booster is essential throughout the lineup.

Our website stands as the go-to online destination for OEM Subaru Outback Brake Booster. With complete lines of genuine Subaru Outback Brake Booster available at unbeatable market prices, we ensure top quality, reliability, and durability. Each part comes backed by the manufacturer's warranty, reinforcing your trust in our offerings.

Subaru Outback Brake Booster Parts Questions & Experts Answers

Vacuum BSTR Assembly LH
26402AE32A
Q:
How to test and replace the power brake booster on Subaru Outback?
Posted by Dan K.
A:
The power brake booster needs only regular checks of the vacuum hose and case. Test operation by pressing the brake pedal several times with the engine off, ensuring no change in pedal reserve distance. If the pedal lowers slightly when the engine is on, it's functioning correctly. Test air tightness by starting the engine, turning it off after a minute, then pressing the pedal slowly a few times. If the pedal lowers initially but rises after a few presses, the booster is airtight. If defective, replace the booster. Removal involves disconnecting the vacuum hose, removing the master cylinder, disconnecting the booster pushrod clevis, and removing the four booster-to-firewall nuts. Reverse these steps for installation, adjust the pushrod if needed, and bleed the brakes.
Answered by Subaru Parts Specialist William / May 21, 2022