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Mercury Mountaineer Expansion Tank

4 items

Coolant expansion tank cracks can cause leaks, low coolant warnings, and overheating. Replace a worn reservoir tank with A-Premium and keep your cooling system protected.

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Engine Coolant Expansion Tank for Ford Explorer Mercury Mountaineer 2006-2010Engine Coolant Expansion Tank for Ford Explorer Mercury Mountaineer 2006-2010
A-Premium®Part # APET0156
Engine Coolant Expansion Tank for Ford Explorer Mercury Mountaineer 2006-2010
4.890 Reviews
$56.99
Low stock: Only 3 left
Edit ZIP code
2-year warranty
90 days free return
Fits 2006 - 2010 Ford Explorer, 2006 - 2010 Ford Explorer, 2007 - 2010 Ford Explorer Sport Trac, 2007 - 2010 Ford Explorer Sport Trac, 2006 - 2010 Mercury Mountaineer, 2006 - 2010 Mercury Mountaineer
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: Mercury Mountaineer
Item LocatedUnited States
Quantity1
Installation PositionFront
ColorWhite
item #1003SXZ9
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Windshield Washer Fluid Reservoir for Ford Ranger 1995-2011 Mercury
A-Premium®Part # APET0286
Windshield Washer Fluid Reservoir for Ford Ranger 1995-2011 Mercury
4.890 Reviews
$68.99
Low stock: Only 5 left
Edit ZIP code
2-year warranty
90 days free return
Fits 1995 - 2001 Ford Explorer, 2001 - 2005 Ford Explorer Sport Trac, 2000 - 2001 Ford F-100, 1995 - 2011 Ford Ranger, 1997 - 2001 Mercury Mountaineer
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: Mercury Mountaineer
Item LocatedUnited States
Installation PositionFront
ColorWhite
item #1003SYTU
Note
【Note-1】This item fits 2000 Ford Explorer 2-Door it only fits the model without Message Center.
【Note-2】This item fits 2000-2001 Ford Explorer 4-Door it only fits the model Low Fluid Sensor.
【Note-3】This item fits 2000-2001 Ford Explorer 4-Door it only fits the model Low Fluid Sensor.
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Engine Timing Cover Gasket Set for Ford F-150 79-96 F-250 F-350 Lincoln Mercury
A-Premium®Part # APET760PG
Engine Timing Cover Gasket Set for Ford F-150 79-96 F-250 F-350 Lincoln Mercury
4.890 Reviews
$20.99
Low stock: Only 5 left
Edit ZIP code
2-year warranty
90 days free return
Fits 1987 - 1989 De Tomaso Pantera, 1979 - 1996 Ford Bronco, 1987 - 1991 Ford Country Squire, 1979 - 1983 Ford E-100 Econoline, 1979 - 1983 Ford E-100 Econoline Club Wagon, 1979 - 1996 Ford E-150 Econoline, 1979 - 1996 Ford E-150 Econoline Club Wagon, 1979 - 1996 Ford E-250 Econoline, 1979 - 1991 Ford E-250 Econoline Club Wagon, 1979 - 1996 Ford E-350 Econoline, 1979 - 1996 Ford E-350 Econoline Club Wagon, 1996 - 1996 Ford Econoline Super Duty, 1996 - 2001 Ford Explorer, 1979 - 1983 Ford F-100, 1979 - 1996 Ford F-150, 1979 - 1997 Ford F-250, 1997 - 1997 Ford F-250 HD, 1979 - 1997 Ford F-350, 1979 - 1982 Ford Fairmont, 1979 - 1981 Ford Granada
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: Mercury Mountaineer
Item LocatedUnited States
QuantityOne Set
ConditionNew
item #1018A5NH
Note
【Note-1】with Sleeve 'N' Seal.
【Note-2】Water Pump to Plate Gasket Not Included.
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Universal Coolant Radiator Reservoir Bottle Overflow Tank White with Cap
A-Premium®Part # APET0327
Universal Coolant Radiator Reservoir Bottle Overflow Tank White with Cap
4.890 Reviews
$19.99
Low stock: Only 3 left
Edit ZIP code
2-year warranty
90 days free return
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: Mercury Mountaineer
Item LocatedUnited States
Quantity1
Part interchange
603-001
item #10055GUK
Show less

Shop coolant expansion tanks and engine coolant reservoirs by vehicle. The right tank gives heated coolant room to expand and provides a place to monitor the level, but layouts differ across cooling systems. Use the year, make, model, engine, and product notes to compare tank shape, hose ports, mounting points, and included components before ordering. Never open the cooling system while the engine is hot.

What Does a Coolant Expansion Tank Do?

As coolant warms, its volume increases. Depending on the vehicle's design, an expansion tank or reservoir receives the changing coolant volume and helps the system maintain the correct operating level. Many tanks have MIN/MAX or COLD-FILL marks so the level can be checked without opening the system. The tank is only one part of the cooling circuit; the radiator, water pump, thermostat, hoses, cap, and coolant passages must also work correctly.

Expansion Tank vs. Coolant Reservoir Terminology

Catalogs may use coolant expansion tank, engine coolant reservoir tank, overflow tank, recovery tank, or surge tank for similar-looking parts. They are not always identical. A pressurized expansion or surge tank may use a pressure cap and connect directly to the circulating system, while an overflow bottle may receive coolant through a small hose from the radiator. Match the original configuration rather than relying on the name alone.

Signs of a Cracked or Leaking Tank

Inspect the coolant reservoir tank when you notice a low-coolant warning, a level that keeps dropping, overheating, or coolant odor under the hood. Possible evidence includes cracks, damp seams, staining or dried residue, damaged hose necks, loose connections, and leakage around the cap. These symptoms do not prove the tank itself has failed; radiator hoses, the water pump, thermostat housing, radiator, or other cooling-system components may also leak. Diagnose the source before replacing parts.

Cap, Sensor, Hose, and Fitment Checks

Start with the A-Premium vehicle selector and confirm the year, make, model, engine, trim, and any transmission notes in the listing. Compare the original tank's shape, mounting points, hose connections, fill markings, and OE or interchange numbers. Product configurations vary: some tanks include a cap, level sensor, hose, bracket, or mounting plate, while others require original components to be transferred or purchased separately. Read the Kit Parts Included field and product notes before checkout.

Safe Inspection and Replacement Considerations

Work only after the engine has cooled completely. Never remove an engine coolant reservoir cap while the engine is running or hot because the system may be pressurized. Follow vehicle-specific service information for draining, installation, refilling, and bleeding, and use the coolant specification in the owner's manual. After service, inspect the connections and monitor the cold level. If overheating continues, coolant drops again, or the repair exceeds your experience, stop driving and have the system professionally diagnosed.

FAQ

Do coolant expansion tanks include the cap and level sensor?

Not always. A-Premium listings show tanks with different combinations of caps, level sensors, hoses, brackets, and mounting plates. Check the title, product notes, and Kit Parts Included field for the exact item you are considering.

Are a coolant expansion tank and an overflow reservoir the same thing?

They may describe the same general category, but the actual system can be pressurized or non-pressurized and may route coolant differently. Match the original tank, connections, cap arrangement, and vehicle fitment instead of choosing by terminology alone.

What are common signs of a leaking coolant reservoir?

Cracks, wet seams, dried coolant residue, leaks near the cap or hose necks, repeated low-coolant warnings, and an unexplained falling level are common clues. Because other cooling parts can cause the same symptoms, confirm the leak source first.

Does falling coolant level always mean the expansion tank has failed?

No. The tank, cap, hoses, radiator, water pump, thermostat housing, heater circuit, and internal engine leaks can all contribute to coolant loss. Inspect and diagnose the entire system before replacing a part.

When can I safely open the cooling system?

Park on level ground, switch the engine off, and wait until it is completely cold. Never remove the coolant reservoir cap while the engine is running or hot. Follow the vehicle's specified checking procedure.

Related Blogs

The Role of the Expansion Tank in Automobile Cooling Systems

The car coolant expansion tank is a vital component that accommodates fluid volume changes, maintains proper pressure, and removes air bubbles, ensuring efficient cooling system operation through a pressurized air pocket and durable construction.

Jul 21, 2026

The Need-to-Know Guide on Expansion Tank Replacement

A car expansion tank stores excess coolant, accommodating fluid expansion as the engine heats up. Replacing a malfunctioning expansion tank is essential to avoid overheating, pressure issues, and consequential engine damage in the vehicle.

Jul 21, 2026