How to Remove and Install a Radiator and Coolant Reservoir on Subaru Outback?

Set the parking brake, raise the vehicle, and remove the splash shield. Drain the cooling system, remove the air intake duct, coolant reservoir, and disconnect radiator hoses. Disconnect fan connectors, remove radiator brackets, and lift out the radiator and cooling fans. Inspect the radiator for damage and clean with a hose. Check and replace radiator mounts if needed. Reinstall in reverse order, ensuring the radiator seats completely. Refill the cooling system with coolant, check for leaks, and adjust coolant level. Check transaxle fluid, remove and clean the coolant reservoir. Drain some coolant, remove the top engine cover and tank. Reinstall and refill with coolant.

Genuine Subaru Outback Coolant Reservoir

Coolant Tank Reservoir

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10 Coolant Reservoirs found

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Subaru Outback Reserve Tank Assembly Radiator
Part Number: 45150FE000
$57.37 MSRP: $83.15
You Save: $25.78 (31%)
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Product Specifications
- Other Name: Reserve Tank Assembly-Radiator; Reservoir Assembly
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 2004 Subaru Outback | Baja-B | 2.5L H4 Turbo
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Subaru Outback Tank Reserve
Part Number: 45150AG00A
$58.57 MSRP: $84.88
You Save: $26.31 (31%)
Ships in 1-3 Business Days
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Product Specifications
- Other Name: Reserve Tank Assembly-Radiator; Reservoir, Reservoir Assembly
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 2005-2019 Subaru Outback | 2.5GT Limited, 2.5GT Premium, 2.5i, 2.5i Base, 2.5i Limited, 2.5i Premium, 2.5i Sport, 2.5i Touring, 3.0R, 3.0R Limited, 3.0R LL-Bean, 3.6R, 3.6R Limited, 3.6R Premium, 3.6R Touring, Base | 2.5L H4, 2.5L H4 DOHC, 2.5L H4 SOHC, 2.5L H4 Turbo, 3.0L H6, 3.6L H6
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Subaru Outback Tank Reserve Assembly
Part Number: 45150AN00A
$16.99 MSRP: $24.62
You Save: $7.63 (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 Tank Assembly Water
Part Number: 21132AA121
$80.67 MSRP: $116.92
You Save: $36.25 (31%)
Ships in 1-2 Business Days
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Product Specifications
- Other Name: Tank Assembly-Water; Tank
- Replaces: 21132AA120
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 2005-2009 Subaru Outback | GT, GT Limited, XT Limited | 2.5L H4 Turbo
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Subaru Outback Tank Assembly Water
Part Number: 21132AA075
$117.20 MSRP: $169.85
You Save: $52.65 (31%)
Ships in 1-2 Business Days
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Product Specifications
- Other Name: Tank Assembly-Water
- Replaced by: 21132AA131
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 2004 Subaru Outback | Baja-B | 2.5L H4 Turbo
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Subaru Outback Tank Reserve
Part Number: 45150AE00A
$50.98 MSRP: $73.88
You Save: $22.90 (31%)
Ships in 1-3 Business Days
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Product Specifications
- Other Name: Reserve Tank Assembly-Radiator; Reservoir Assembly
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 2000-2004 Subaru Outback | Baja, Baja-S, Base, Brighton, Cold Weather, GT, L, Limited, L-S, SUS Limited | 2.5L H4
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Subaru Outback Tank Assembly Water
Part Number: 21132AA120
$80.67 MSRP: $116.92
You Save: $36.25 (31%)
Ships in 1-2 Business Days
ADD TO CART
Product Specifications
- Other Name: Tank Assembly-Water
- Replaced by: 21132AA121
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 2005-2009 Subaru Outback | GT, GT Limited, XT Limited | 2.5L H4 Turbo
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Subaru Outback Tank Reserve
Part Number: 45150AE01A
$25.46 MSRP: $36.90
You Save: $11.44 (31%)
Ships in 1-2 Business Days
ADD TO CART
Product Specifications
- Other Name: Reserve Tank Assembly-Radiator; Reservoir Assembly
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 2001-2004 Subaru Outback | Flat6, Flat6 L.L.Bean, Flat6-S, SUS Flat6 | 3.0L H6
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Subaru Outback Tank Reserve
Part Number: 45150AG01A
$51.13 MSRP: $74.10
You Save: $22.97 (31%)
Ships in 1-3 Business Days
ADD TO CART
Product Specifications
- Other Name: Reserve Tank Assembly-Radiator; Reservoir Assembly
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 2005-2009 Subaru Outback | GT, GT Limited, XT Limited | 2.5L H4 Turbo
View related parts
Subaru Outback Reserve Tank Assembly
Part Number: 45151AC000
$52.15 MSRP: $75.58
You Save: $23.43 (31%)
Product Specifications
- Other Name: Reserve Tank Assembly-Radiator; Reservoir Assembly
- Warranty: This genuine part is guaranteed by Subaru's factory warranty.
Fits the following Vehicles:
- 1996-1999 Subaru Outback | Brighton, GT, L, LS, LS-I, Out Back, Post, SUS | 2.2L H4 , 2.2L H4 (New EVAPO), 2.2L H4 Series, 2.5L H4

Subaru Outback Coolant Reservoir

The Subaru Outback Coolant Reservoir maintains air in the cooling circuit and stores excess engine coolant. The plastic tank, which connects to the radiator, receives fluid when it expands due to increased heat and pressure. Likewise, it returns the liquid when the heat and pressure fall. Thus, the liquid will not overflow and will maintain the levels of these fluids in the engine. Molded level markings indicate the correct fill range that is usually checked with the engine cold. Outback utilizes an overflow arrangement and an expansion arrangement as two operational styles. In overflow style, the pressure cap sits on the radiator. The Coolant Reservoir has a simple plastic cap. The simple valve opens to take in coolant when pressure from the radiator overcomes a spring. The valve closes on its own when the pressure is removed. As coolant cools down and a vacuum forms in the radiator, the simple valve opens again to let coolant from the Coolant Reservoir return to the radiator. The expansion type of Coolant Reservoir has the pressure cap itself. The expansion type of Coolant Reservoir is constructed of reinforced plastic and is positioned at the high point of the system. It releases air, but not liquid. When pressure exceeds the rating, it vents out the air. When the engine cools and the coolant contracts, the atmospheric pressure forces air back in. By ensuring safe antifreeze management and reliable temperature control on every Subaru Outback journey, these features ultimately contribute to Subaru cooling performance.

Our website stands as the go-to online destination for OEM Subaru Outback Coolant Reservoir. With complete lines of genuine Subaru Outback Coolant Reservoir 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 Coolant Reservoir Parts Questions & Experts Answers

Tank Assembly Water
21132AA120
Q:
How to Remove and Install a Radiator and Coolant Reservoir on Subaru Outback?
Posted by Nathanael C.
A:
Set the parking brake, raise the vehicle, and remove the splash shield. Drain the cooling system, remove the air intake duct, coolant reservoir, and disconnect radiator hoses. Disconnect fan connectors, remove radiator brackets, and lift out the radiator and cooling fans. Inspect the radiator for damage and clean with a hose. Check and replace radiator mounts if needed. Reinstall in reverse order, ensuring the radiator seats completely. Refill the cooling system with coolant, check for leaks, and adjust coolant level. Check transaxle fluid, remove and clean the coolant reservoir. Drain some coolant, remove the top engine cover and tank. Reinstall and refill with coolant.
Answered by Subaru Parts Specialist Diego / May 05, 2026