How to replace the coolant reservoir and radiator on Audi A4?

To carry out the task of replacement of the radiator, first raise the front of the vehicle and hold it firmly on jackstands. Take off the bottom splash cover and empty the cooling system. Secondly, remove engine covers and front bumper and in 2.0L models, position radiator support panel in service position. Detach the upper and lower transaxle cooler lines of the automatic and seal them with a cap. Have the upper and bottom radiator hose clips lifted to detach the hose to the radiator and twist them (where needed) to release the O-ring. Take out the ducts by removing the air duct fasteners of either side of the radiator. Unplug the air conditioning pressure switch and ambient temperature sensor on the driver side of radiator and position the harness aside. Disassemble the mounting fasteners of the power steering cooler and drop the cooler without unscrewing the lines where provided. Removal of air conditioning condenser mounting fasteners and rotate the condenser out of and down the radiator, careful not to kink, stretch or bend the air conditioning lines. Unscrew the two radiator mounting pins, push the pins upwards to unscrew then remove the radiator. Installation of new radiator Before fitting the new radiator, replace any damaged hose clips, radiator hoses, and O-rings. Installation is done in the same manner as it is removed. Installation Refill and bleed the system and then start the engine checking all the leaks. In the case of expansion tank, empty the cooling system by draining it until the coolant drier is removed. Removal: Before removing the tank out of the engine compartment, take out the expansion tank mounting screw, lift the tank and disconnect the coolant level sensor connector. The reservoir should be clean and clear, so wash the reservoir with soapy water, and rinse thoroughly, etc. Installation is done in the same manner as it is removed.

Genuine Audi Coolant Reservoir

Coolant Tank Reservoir

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59 Coolant Reservoirs found

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Audi Expansion Tank Part Number: 4M0-121-403-G
$24.61 MSRP: $39.38
You Save: $14.77 (38%)
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Product Specifications
- Other Name: Tank; Expansion Tank, Reservoir
- Replaces: 4M0-121-403-C, 4M0-121-403-E
Fits the following Audi Models:
- Q7 | 2020-2023 | Premium, Premium Plus, Prestige | 6 Cyl 3.0 L MILD HYBRID EV-GAS (MHEV)
- Q8 | 2019-2023 | Premium, Premium Plus, Prestige | 6 Cyl 3.0 L MILD HYBRID EV-GAS (MHEV)
- RS Q8 | 2020-2023 | Base | 8 Cyl 4.0 L MILD HYBRID EV-GAS (MHEV)
- SQ7 | 2020-2023 | Premium Plus, Prestige | 8 Cyl 4.0 L MILD HYBRID EV-GAS (MHEV)
- SQ8 | 2020-2023 | Premium Plus, Prestige | 8 Cyl 4.0 L MILD HYBRID EV-GAS (MHEV)
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Audi Expansion Tank Part Number: 4N0-121-405-AJ
$62.39 MSRP: $87.38
You Save: $24.99 (29%)
Ships in 1-2 Business Days
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Product Specifications
- Other Name: Tank; Expansion Tank, Reservoir
- Replaces: 4N0-121-405-N
Fits the following Audi Models:
- A8 Quattro | 2019-2021 | L | 8 Cyl 4.0 L MILD HYBRID EV-GAS (MHEV)
- S8 | 2020-2023 | Base | 8 Cyl 4.0 L MILD HYBRID EV-GAS (MHEV)
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Audi Expansion Tank Part Number: 8K0-121-403-AC
$73.78 MSRP: $103.34
You Save: $29.56 (29%)
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Product Specifications
- Other Name: Tank; Expansion Tank, Reservoir
- Replaces: 8K0-121-403-T, 8K0-121-403-G, 8K0-121-403-H, 8K0-121-403-D, 8K0-121-403-Q
Fits the following Audi Models:
- A4 | 2009-2016 | Base, Premium, Premium Plus, Prestige | 4 Cyl 2.0 L GAS
- A4 Quattro | 2009-2016 | Avant, Base, Premium, Premium Plus, Prestige | 4 Cyl 2.0 L FLEX, 4 Cyl 2.0 L GAS
- A5 | 2010-2014 | Cabriolet | 4 Cyl 2.0 L GAS
- A5 Quattro | 2008-2017 | Base, Cabriolet, Premium, Premium Plus, Prestige, Sport | 4 Cyl 2.0 L FLEX, 4 Cyl 2.0 L GAS, 6 Cyl 3.2 L GAS
- Q5 | 2011-2017 | Hybrid Prestige, Premium, Premium Plus | 4 Cyl 2.0 L FLEX, 4 Cyl 2.0 L FULL HYBRID EV-GAS (FHEV), 4 Cyl 2.0 L GAS
- allroad | 2013-2016 | Premium, Premium Plus, Prestige | 4 Cyl 2.0 L FLEX
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Audi Reservoir Part Number: 8D0-121-403-D
$65.45 MSRP: $91.67
You Save: $26.22 (29%)
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Product Specifications
- Other Name: Tank
Fits the following Audi Models:
- A4 | 1997-2001 | Base | 4 Cyl 1.8 L GAS
- A4 Quattro | 1997-2001 | Avant, Base | 4 Cyl 1.8 L GAS
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Audi Expansion Tank Part Number: 4N0-121-405-AF
$195.16 MSRP: $273.33
You Save: $78.17 (29%)
Ships in 1-2 Business Days
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Product Specifications
- Other Name: Tank; Expansion Tank, Reservoir
- Replaces: 4N0-121-405-B, 4N0-121-405-P
Fits the following Audi Models:
- A8 Quattro | 2019-2023 | L, L Plug-In Hybrid | 6 Cyl 3.0 L MILD HYBRID EV-GAS (MHEV), 6 Cyl 3.0 L PLUG-IN HYBRID EV-GAS (PHEV), 8 Cyl 4.0 L MILD HYBRID EV-GAS (MHEV)
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Audi Expansion Tank Part Number: 4F0-121-403-M
$78.54 MSRP: $110.01
You Save: $31.47 (29%)
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Product Specifications
- Other Name: Tank; Reservoir Tank
- Replaces: 4F0-121-403-F, 4F0-121-403-B, 4F0-121-403
Fits the following Audi Models:
- A6 Quattro | 2005-2011 | Base | 8 Cyl 4.2 L GAS
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Audi Expansion Tank Part Number: 4F0-121-403-N
$77.10 MSRP: $107.99
You Save: $30.89 (29%)
Ships in 1-2 Business Days
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Product Specifications
- Other Name: Tank; Expansion Tank
- Replaces: 4F0-121-403-C, 4F0-121-403-G
Fits the following Audi Models:
- A6 | 2006-2011 | Base | 6 Cyl 3.2 L GAS
- A6 Quattro | 2005-2011 | Avant, Base | 6 Cyl 3.0 L GAS, 6 Cyl 3.2 L GAS
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Audi Expansion Tank Part Number: 4K0-121-405-AC
$82.11 MSRP: $114.99
You Save: $32.88 (29%)
Ships in 1-2 Business Days
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Product Specifications
- Other Name: Tank; Expansion Tank, Reservoir, Reservoir Tank
Fits the following Audi Models:
- A6 Quattro | 2021-2023 | Premium, Premium Plus, Prestige | 6 Cyl 3.0 L MILD HYBRID EV-GAS (MHEV)
- A6 allroad | 2021-2023 | Premium Plus, Prestige | 6 Cyl 3.0 L MILD HYBRID EV-GAS (MHEV)
- A7 Sportback | 2019-2023 | Premium, Premium Plus, Prestige | 6 Cyl 3.0 L MILD HYBRID EV-GAS (MHEV)
- RS6 Avant | 2021-2023 | Base | 8 Cyl 4.0 L MILD HYBRID EV-GAS (MHEV)
- RS7 Sportback | 2021-2023 | Base | 8 Cyl 4.0 L MILD HYBRID EV-GAS (MHEV)
- S6 | 2021-2023 | Premium, Premium Plus, Prestige | 6 Cyl 2.9 L MILD HYBRID EV-GAS (MHEV)
- S7 Sportback | 2021-2023 | Premium, Premium Plus, Prestige | 6 Cyl 2.9 L MILD HYBRID EV-GAS (MHEV)
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Audi Reservoir Part Number: 8E0-121-403
$76.15 MSRP: $106.65
You Save: $30.50 (29%)
Ships in 1-2 Business Days
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Product Specifications
- Other Name: Tank
Fits the following Audi Models:
- A4 | 2002-2009 | Base, Cabriolet | 4 Cyl 1.8 L GAS, 4 Cyl 2.0 L GAS, 6 Cyl 3.2 L GAS
- A4 Quattro | 2002-2009 | Avant, Base, Cabriolet | 4 Cyl 1.8 L GAS, 4 Cyl 2.0 L GAS, 6 Cyl 3.2 L GAS
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Audi Reservoir Part Number: 4D0-121-403-C
$74.97 MSRP: $105.00
You Save: $30.03 (29%)
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Product Specifications
- Replaces: 4D0-121-403-A, 4D0-121-403-B
Fits the following Audi Models:
- A8 | 1997-1999 | Base | 8 Cyl 3.7 L GAS
- A8 Quattro | 1997-2003 | Base, L | 8 Cyl 4.2 L GAS
- S8 | 2001-2003 | Base | 8 Cyl 4.2 L GAS
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Audi Reservoir Part Number: 8E0-121-403-F
$88.06 MSRP: $123.33
You Save: $35.27 (29%)
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Product Specifications
- Other Name: Tank
Fits the following Audi Models:
- RS4 | 2007-2008 | Base, Cabriolet | 8 Cyl 4.2 L GAS
- S4 | 2004-2009 | Avant, Base, Cabriolet | 8 Cyl 4.2 L GAS
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Audi Expansion Tank Part Number: 4F0-121-403-T
$105.91 MSRP: $148.33
You Save: $42.42 (29%)
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Product Specifications
- Other Name: Tank
Fits the following Audi Models:
- A6 Quattro | 2010-2011 | Avant, Base | 6 Cyl 3.0 L GAS
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Audi Expansion Tank Part Number: 5Q0-121-407-P
$91.63 MSRP: $128.33
You Save: $36.70 (29%)
Ships in 1-2 Business Days
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Product Specifications
- Other Name: Tank; Expansion Tank, Reservoir
- Replaces: 5Q0-121-407-H
Fits the following Audi Models:
- A3 Sportback e-tron | 2016-2018 | Premium, Premium Plus, Prestige | 4 Cyl 1.4 L PLUG-IN HYBRID EV-GAS (PHEV)
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Audi Expansion Tank Part Number: 4KE-121-405-A
$103.52 MSRP: $144.98
You Save: $41.46 (29%)
Ships in 1-2 Business Days
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Product Specifications
- Other Name: Tank; Expansion Tank, Reservoir
Fits the following Audi Models:
- Q8 e-tron | 2024 | Launch Edition, Premium, Premium Plus, Prestige | BATTERY EV (EV/BEV)
- Q8 e-tron Sportback | 2024 | Launch Edition, Premium, Premium Plus, Prestige | BATTERY EV (EV/BEV)
- e-tron Quattro | 2021-2023, 2019 | Chronos Edition, Premium, Premium Plus, Prestige | BATTERY EV (EV/BEV)
- e-tron S | 2022-2023 | Premium Plus, Prestige | BATTERY EV (EV/BEV)
- e-tron S Sportback | 2022-2023 | Premium Plus, Prestige | BATTERY EV (EV/BEV)
- e-tron Sportback | 2020-2023 | Premium, Premium Plus, Prestige | BATTERY EV (EV/BEV)
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Audi Reservoir Part Number: 8D0-121-403-L
$86.86 MSRP: $121.65
You Save: $34.79 (29%)
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Product Specifications
- Other Name: Tank
Fits the following Audi Models:
- A4 | 1996-2001 | Avant, Base | 6 Cyl 2.8 L GAS
- A4 Quattro | 1996-2001 | Avant, Base | 6 Cyl 2.8 L GAS
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Audi Expansion Tank Part Number: 4H0-121-403-M
$99.96 MSRP: $140.01
You Save: $40.05 (29%)
Ships in 1-2 Business Days
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Product Specifications
- Other Name: Tank; Expansion Tank, Reservoir
- Replaces: 4H0-121-403-G
Fits the following Audi Models:
- A8 Quattro | 2011-2018 | Base, L, L TDI, L W12 | 12 Cyl 6.3 L GAS, 6 Cyl 3.0 L DIESEL, 6 Cyl 3.0 L GAS, 8 Cyl 4.2 L GAS
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Audi Expansion Tank Part Number: 4H0-121-403-N
$98.77 MSRP: $138.34
You Save: $39.57 (29%)
Ships in 1-2 Business Days
ADD TO CART
Product Specifications
- Other Name: Tank; Expansion Tank, Reservoir
- Replaces: 4H0-121-403-H
Fits the following Audi Models:
- A8 Quattro | 2013-2018 | Base, L, L Sport, L W12 | 12 Cyl 6.3 L GAS, 8 Cyl 4.0 L GAS
- S8 | 2013-2018 | Base, Plus | 8 Cyl 4.0 L GAS
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Audi Expansion Tank Part Number: 4F0-121-403-AA
$113.05 MSRP: $158.33
You Save: $45.28 (29%)
Ships in 1-2 Business Days
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Product Specifications
- Other Name: Tank; Reservoir
- Replaces: 4F0-121-403-E, 4F0-121-403-P
Fits the following Audi Models:
- S6 | 2007-2011 | Base | 10 Cyl 5.2 L GAS
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Audi Reservoir Part Number: 5Q0-121-407-Q
$105.78 MSRP: $148.14
You Save: $42.36 (29%)
Ships in 1-2 Business Days
ADD TO CART
Product Specifications
- Other Name: Tank; Reservoir
- Replaces: 5Q0-121-407-J
Fits the following Audi Models:
- A3 Sportback e-tron | 2018 | Premium, Premium Plus, Prestige | 4 Cyl 1.4 L PLUG-IN HYBRID EV-GAS (PHEV)
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Audi Expansion Tank Part Number: 4B3-121-403-B
$99.96 MSRP: $140.00
You Save: $40.04 (29%)
Ships in 1-2 Business Days
ADD TO CART
Product Specifications
- Other Name: Tank
Fits the following Audi Models:
- A6 Quattro | 2000-2004 | Base | 8 Cyl 4.2 L GAS
- S6 | 2002-2003 | Avant | 8 Cyl 4.2 L GAS

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Audi Coolant Reservoir

The Audi Coolant Reservoir is a very important part of your vehicle. Therefore, it has to be maintained in good condition to avoid performance issues and comfortable driving. And these regular checks and replacements will ultimately save you some big repair costs. It is better to choose OEM parts when it comes to the time for fixing them. Why? Because they fit perfectly well and ensure safety. For people who prefer doing their maintenance, the genuine Audi Coolant Reservoir is quite perfect. At AudiPartsGiant.com, we specialize in genuine Audi Coolant Reservoirs only. Also, we offer an extensive online catalog with many categories, ample stock, and secure shopping. The Audi Coolant Reservoir is shipped directly from authorized Audi dealers at competitive prices. So trust us, and we will give you nothing but superior service. Depend on us for all your genuine parts needs, and then we will keep your automobile moving smoothly.

Audi Coolant Reservoir Parts and Q&A

Reservoir
8E0-121-403
Q: How to replace the coolant reservoir and radiator on Audi A4?
A:
To carry out the task of replacement of the radiator, first raise the front of the vehicle and hold it firmly on jackstands. Take off the bottom splash cover and empty the cooling system. Secondly, remove engine covers and front bumper and in 2.0L models, position radiator support panel in service position. Detach the upper and lower transaxle cooler lines of the automatic and seal them with a cap. Have the upper and bottom radiator hose clips lifted to detach the hose to the radiator and twist them (where needed) to release the O-ring. Take out the ducts by removing the air duct fasteners of either side of the radiator. Unplug the air conditioning pressure switch and ambient temperature sensor on the driver side of radiator and position the harness aside. Disassemble the mounting fasteners of the power steering cooler and drop the cooler without unscrewing the lines where provided. Removal of air conditioning condenser mounting fasteners and rotate the condenser out of and down the radiator, careful not to kink, stretch or bend the air conditioning lines. Unscrew the two radiator mounting pins, push the pins upwards to unscrew then remove the radiator. Installation of new radiator Before fitting the new radiator, replace any damaged hose clips, radiator hoses, and O-rings. Installation is done in the same manner as it is removed. Installation Refill and bleed the system and then start the engine checking all the leaks. In the case of expansion tank, empty the cooling system by draining it until the coolant drier is removed. Removal: Before removing the tank out of the engine compartment, take out the expansion tank mounting screw, lift the tank and disconnect the coolant level sensor connector. The reservoir should be clean and clear, so wash the reservoir with soapy water, and rinse thoroughly, etc. Installation is done in the same manner as it is removed.