EVIL ENERGY Overflow Tank Coolant Radiator Tank Reservoir Expansion Universal Aluminum 1L/2L

Q: Which size should I choose for my build, the 1L or the 2L Coolant Overflow Tank?

A: Choose the 1L Coolant Overflow Tank for compact engine bays, 4-cylinder and 6-cylinder engines, Miata or import swaps, and ATVs or UTVs. Choose the 2L Coolant Overflow Tank for V8 and LS swaps, large aluminum radiators, trucks that tow, and vehicles driven in hot states like Arizona and Texas, where coolant expands more. When in doubt and space allows, the 2L tank gives a larger safety margin.

Q: Can the universal aluminum tank replace the pressurized expansion tank on my BMW, VW or Chevy Cruze?

A: No. The universal Coolant Overflow Tank is a recovery tank for cooling systems where the pressure cap sits on the radiator or filler neck. Many modern cars, including the BMW 3 Series, Volkswagen Jetta and Chevy Cruze, use a pressurized expansion tank that carries the pressure cap and is part of the sealed system. For those vehicles, choose a vehicle-specific coolant reservoir tank matched to the OE part number.

Q: Where is the best place to mount the Coolant Overflow Tank in an LS-swapped engine bay?

A: Mount the tank upright on a solid surface, close enough to the radiator filler neck for a short overflow hose, and away from exhaust headers, belts and the fan. Common spots include the inner fender, the core support or the firewall. Avoid mounting directly above the headers, since radiant heat can boil the coolant inside the tank.

Q: How do I connect the hoses to the bottom port and top port?

A: Connect the bottom port to the overflow nipple on the radiator neck with 3/8 in ID hose. The bottom connection lets coolant flow into the tank when hot and get drawn back into the radiator as the engine cools. Use the top port as the vent, or route the top port down to a safe drain point. Reversing the hoses prevents coolant from returning to the radiator.

Q: Does the kit include a mounting bracket and hose?

A: The package includes the aluminum Coolant Overflow Tank, a billet aluminum cap, two M14 × 1.5 to 12 mm hose barb fittings, a magnetic drain plug and a level sensor. Mounting brackets and hose are not listed in the package, so plan for brackets or straps that suit your mounting location and enough 3/8 in ID hose for the overflow and vent lines.

Q: Why is coolant coming out of the top vent of my overflow tank?

A: Common causes include overfilling the Coolant Overflow Tank, a weak or wrong-rated radiator cap that releases pressure too early, an engine that is overheating, or air and combustion gases pushing coolant out of the system. Fill the tank to about one-third when cold, test the radiator cap, and check for overheating. If bubbles keep appearing in the tank with a warm engine, have the cooling system pressure-tested and check for a head gasket problem.

Q: What type of coolant can I use in an aluminum Coolant Overflow Tank?

A: Use the same coolant that is already in the cooling system, such as an ethylene glycol antifreeze rated for aluminum engines and radiators, mixed 50/50 with distilled water. Avoid running straight water in northern states or Canada during winter, because water can freeze and damage the tank, radiator and engine block. Do not mix different coolant chemistries in one system.

Q: Do I need Teflon tape on the fittings if the threads already have O-rings?

A: The O-rings provide the main seal. If a fitting still seeps after tightening, wrap a few turns of Teflon tape on the threads only, keeping the tape away from the O-ring and the sealing face. Tighten the aluminum fittings snugly by hand plus a small turn with a wrench; over-tightening can damage the threads or pinch the O-ring.

Q: When should I use the magnetic drain plug?

A: Use the magnetic drain plug whenever you flush or change coolant, or when the coolant in the tank looks dirty or rusty. Remove the plug, drain the tank, wipe off any metal particles the magnet has collected, then reinstall the plug with its O-ring. Heavy metal debris on the magnet can signal water pump or engine wear worth investigating.

Q: Will the Coolant Overflow Tank work on an ATV, UTV or side-by-side?

A: Yes, the 1L Coolant Overflow Tank is a common replacement for cracked plastic bottles on ATVs, UTVs and side-by-sides, provided the machine's radiator carries the pressure cap. Measure the mounting area first, use rubber-isolated mounts or brackets to reduce vibration, and secure the overflow hose away from moving suspension parts and hot exhaust.