How to replace the coolant reservoir and radiator on Volkswagen Passat?

The steps involved in substituting the radiator include first lifting the front of the car and ensuring that it rests on jackstands and then emptying the cooling system. Place the radiator support panel in an accessible location and unscrew the upper and lower hoses of the coolant through prying the clip out of shape and removing the hoses off the radiator and the fan thermo switch electrical connector. In the cases of an automatic transaxle, un-hook transmission oil cooler lines at the lower section of the radiator. In cars that have air conditioning, remove the air conditioning line retaining clamps, loosen the condenser mounting bolts and unbreech the condenser and the radiator without breaking the lines and attach it to the body using wire so that it is not held loose. The second step is to remove the radiator mounting clips and the radiator out of the support panel. Prior to fitting the new radiator, any broken hose clips and fittings should be replaced and radiator checked and cleaned in case of leaks or other cooling problems. Installation is done in reverse sequence of removal and once we have installed, fill the system with correct antifreeze mixture and remove all the air in the cooling system. To perform the expansion tank, drain the system until it is dry, disconnect the coolant recovery hoses, disconnect the reservoir mounting bolts, lift the expansion tank off the firewall, and disconnect the coolant level sensor connector, and then leave the expansion tank out of engine compartment. The reservoir must be clean and free of debris before installation, and it is done in the same order as it is removed, too.

Genuine Volkswagen Passat Coolant Reservoir

Coolant Tank Reservoir

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4 Coolant Reservoirs found

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Volkswagen Passat Reservoir Part Number: 1K0-121-407-F
$58.43 MSRP: $81.16
You Save: $22.73 (29%)
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Product Specifications
- Other Name: Tank
- Warranty: This genuine part is guaranteed by Volkswagen's factory warranty.
Fits the following Vehicles:
- 2012-2022, 2006-2010 Volkswagen Passat | 2.0T, 3.6, GT, Komfort, Limited Edition, Lux, R-Line, S, SE, SE R-Line, SEL, SEL Premium, Sport, TDI SE, TDI SEL, TDI SEL Premium, Turbo, Value Edition, VR6, Wolfsburg Edition | 4 Cyl 1.8 L GAS, 4 Cyl 2.0 L DIESEL, 4 Cyl 2.0 L GAS, 5 Cyl 2.5 L GAS, 6 Cyl 3.6 L GAS
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Volkswagen Passat Reservoir Part Number: 3B0-121-407-B
$60.69 MSRP: $85.00
You Save: $24.31 (29%)
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Product Specifications
- Other Name: Tank
- Warranty: This genuine part is guaranteed by Volkswagen's factory warranty.
Fits the following Vehicles:
- 2002-2004 Volkswagen Passat | W8 | 8 Cyl 4.0 L GAS
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Volkswagen Passat Reservoir Part Number: 1H0-121-407-A
$112.44 MSRP: $157.48
You Save: $45.04 (29%)
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Product Specifications
- Other Name: Tank; Reservoir Tank
- Replaces: 5X0-121-407-A
- Warranty: This genuine part is guaranteed by Volkswagen's factory warranty.
Fits the following Vehicles:
- 1995-1997, 1990-1993 Volkswagen Passat | CL, GL, GLS, TDI | 4 Cyl 1.9 L DIESEL, 4 Cyl 2.0 L GAS
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Volkswagen Passat Reservoir Part Number: 021-121-407
$49.42 MSRP: $68.63
You Save: $19.21 (28%)
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Product Specifications
- Other Name: Tank; Reservoir Tank
- Replaces: 021-121-407-B
- Warranty: This genuine part is guaranteed by Volkswagen's factory warranty.
Fits the following Vehicles:
- 1993-1997 Volkswagen Passat | GLX | 6 Cyl 2.8 L GAS

Volkswagen Passat Coolant Reservoir

The very essence or benefit of the Volkswagen Passat Coolant Reservoir is to hold additional antifreeze and exclude air in the cooling system to ensure that the engine is maintained at a safe temperature without spilling damaging fluid. A plastic tank found in a Volkswagen engine is placed next to the radiator, with lines of MIN and MAX etched into it, and filled up by expanding coolant rather than spilling onto the road, and the coolant is ejected back into the circuit when the temperatures are low to avoid the air pockets that predispose to rust. The model has applied two main designs over the years, the non-pressurized overflow-type and the pressurized expansion-type Coolant Reservoir, and all types of Coolant Reservoir perform the same role. In the overflow design the spring-loaded pressure cap belongs to the radiator and the tank has an uncomplicated plastic lid, such that increasing pressure causes fluid to spray away, and decreasing pressure causes it to spring back. Subsequent Volkswagen models followed the expansion design whereby the metal pressure cap is mounted on the tank itself, constructed of a heavier reinforced plastic, and attached higher than the radiator such that gravity prevents bubbles in the coolant. In this design the cap releases air when pressure is at the high point and pulls air in when a vacuum exists, allowing the fluid to expand and contract without aerating. The two systems secure waterways by encasing the ethylene glycol and metal particles within the loop. One can easily confirm cold levels in the second-generation Volkswagen Passat after looking at the translucent Coolant Reservoir on a cold morning.

Choose OEM Coolant Reservoir for superior quality and long-lasting durability. They match the Volkswagen's factory specifications exactly and pass strict quality control. If you plan to replace Coolant Reservoir on your Passat, put OEM at the top of your list. You'll get the right fit, reliable performance, and peace of mind. We stock an extensive inventory of genuine Volkswagen Passat parts. It is easy to find what you need. You will love our competitive prices that help you save. No more hassle with returns or guesswork. Every part includes a warranty straight from the manufacturer. Get trusted quality, strong durability, and real value today.

Volkswagen Passat Coolant Reservoir Parts and Q&A

Reservoir
3B0-121-407-B
Q: How to replace the coolant reservoir and radiator on Volkswagen Passat?
A:
The steps involved in substituting the radiator include first lifting the front of the car and ensuring that it rests on jackstands and then emptying the cooling system. Place the radiator support panel in an accessible location and unscrew the upper and lower hoses of the coolant through prying the clip out of shape and removing the hoses off the radiator and the fan thermo switch electrical connector. In the cases of an automatic transaxle, un-hook transmission oil cooler lines at the lower section of the radiator. In cars that have air conditioning, remove the air conditioning line retaining clamps, loosen the condenser mounting bolts and unbreech the condenser and the radiator without breaking the lines and attach it to the body using wire so that it is not held loose. The second step is to remove the radiator mounting clips and the radiator out of the support panel. Prior to fitting the new radiator, any broken hose clips and fittings should be replaced and radiator checked and cleaned in case of leaks or other cooling problems. Installation is done in reverse sequence of removal and once we have installed, fill the system with correct antifreeze mixture and remove all the air in the cooling system. To perform the expansion tank, drain the system until it is dry, disconnect the coolant recovery hoses, disconnect the reservoir mounting bolts, lift the expansion tank off the firewall, and disconnect the coolant level sensor connector, and then leave the expansion tank out of engine compartment. The reservoir must be clean and free of debris before installation, and it is done in the same order as it is removed, too.