Installation

Installation Instructions

Green Demon is safe and suitable for use in all water cooled engines from bikes up to big trucks.  Also safe with aluminum heads.  1 bottle will treat engines in cars, SUVs and light trucks.  For bigger vehicles just use 2 bottles.

Green Demon has been engineered to permanently seal coolant leaks in the head, head gasket and block.  Green Demon is not suitable for oil leaks, or repairing damaged hoses or rubber seals in the cooling system.

Traditional Installation
Advanced Installation
Severe Over-Pressurising Systems

Traditional Installation

Step 1

Step 1

With the engine off, unscrew the expansion / header tank cap, or radiator cap if you have one.

Step 2

Shake the bottle vigorously for 30 to 60 seconds to ensure the contents are well mixed.

Step 3

Open the bottle and pour the entire contents into the cooling system. Replace the radiator cap, start the engine and let it idle up to normal operating temperature.

Green Demon will normally make a repair in just a few minutes but in some situations it may take 2 or 3 heat/cool cycles of the engine for the Green Demon magic to take effect.

Pro Tips:  If your cooling system is over pressurizing, blowing combustion gases into the coolant, then you’ll need to bypass the header tank.  If there is no radiator cap then add Green Demon via the top hose of the radiator, or you can drain some coolant, mix that with the Green Demon and then pour that back via the radiator.

To reduce pressure in the cooling system then you can try disabling the spark plug from the offending cylinder that’s blowing gases into the cooling system.

Advanced Installation

If this is a vehicle you have recently purchased or are unsure of the maintenance history then it is advisable to perform a cooling system flush procedure before adding Green Demon.
  • Make sure you shake the bottle thoroughly (at least 30 seconds) to ensure the contents are well mixed. Check the bottle after adding and if necessary add more water and shake again to ensure all contents are added to the system.
  • When adding via the overflow/expansion tank, add Green Demon first and then top up the coolant. This helps to get Green Demon into the cooling system more quickly.
  • It is fine to add Green Demon to a cold cooling system, just let the engine idle up to normal operating temperature. Green Demon can also be added to a hot system but use caution as the system will be under pressure and hot coolant can scald you.

If you add Green Demon directly to the radiator, ensure there is enough coolant to cover the core which (shelf at the top) to ensure that Green Demon is added to fluid rather than hitting the core first. One option is to pre-mix Green Demon in a larger container of water and then add to the radiator. This will assist the dispersal of the Green Demon throughout the cooling system.

Foaming is a rare side effect of adding Green Demon which will not interfere with the repair process. It sometimes occurs with head gasket issues. If you notice foaming, just idle the engine with the expansion or radiator cap off to let the foam escape. Once a repair is made you can drain and flush the system to remove any residual foam.

  • For heater core repairs, set the heater controls in the ON/HOT position and confirm that hot air is blowing before adding Green Demon. If there is no heat in the cabin, there is most likely an air-lock that will hinder Green Demon from circulating. The heater matrix is often the highest point of the cooling system, and any air in the system will gravitate there potentially impeding the flow of coolant. If there is no heat after adding Green Demon bleed the cooling system to remove any air locks.
  • Once Green Demon has been added allow the vehicle to idle for about 20 – 30 minutes. Higher revs or driving the vehicle will increase pressures in the cooling system which can sometimes make a repair more difficult, in particular with head gasket issues.
  • You may also wish to leave the cap off the expansion tank or radiator while idling to vent any air-locks and additionally prevent any vacuum developing as a result of from coolant still leaking.
  • Occasionally with minor leaks, it may take multiple heat / cool cycles for Green Demon to be able to make a repair. Just use the vehicle as you would for up to ten days after and if Green Demon has not made a repair then it is, unfortunately, unlikely to do so.
  • For motorcycles or other small cooling systems with only a couple of quarts/litres capacity, simply add a quarter to half of a regular bottle but make sure the contents are very well shaken first. If the leak remains then add the remainder of the contents.

Severe Over-Pressurizing Systems (Head Gasket) Installation

Coolant being expelled from the expansion or overflow tank while the engine is left idling

In this example, the cap is left off, but even in place, the system would build up the pressure and eventually force coolant out as well as raise the engine temperature as the coolant flow becomes restricted.

Bubbles that are visible in the expansion tank or top of the radiator are combustion gases from the engine getting into the cooling system.

In these instances, the extra pressure can actually prevent Green Demon from entering the cooling system or reaching the failure point. There are a few extra tips to help give Green Demon the best chance of making a repair.

Coolant being expelled from the expansion or overflow tank while the engine is left idling

In this example, the cap is left off, but even in place, the system would build up the pressure and eventually force coolant out as well as raise the engine temperature as the coolant flow becomes restricted.

Bubbles that are visible in the expansion tank or top of the radiator are combustion gases from the engine getting into the cooling system.

In these instances, the extra pressure can actually prevent Green Demon from entering the cooling system or reaching the failure point. There are a few extra tips to help give Green Demon the best chance of making a repair.

  • Adding Green Demon via the top hose of the radiator, or draining some coolant and mixing with Green Demon before adding back to the system, can help to get Green Demon into the cooling system more rapidly.
  • If you can identify the problem cylinder then by disabling or removing the spark plug you will reduce the pressure blowing into the cooling system. This gives Green Demon more chance to reach and enter the failure point. Disabling the injector can also help, particularly in diesel engines where there is no spark plug.
  • Another effective method is to idle the engine with the highest point bleed valve open which vents the combustion gases early and stops over-pressurising which has been demonstrated to then allow Green Demon to work. If possible, you can also add Green Demon while the front of the vehicle is elevated up to 45 degrees by parking on an incline. This allows any air in the system to rise and reach the expansion tank and escape.

Sometimes the failure is simply too large for Green Demon to make a repair. Green Demon is specifically engineered to seal holes up to 0.635mm / 0.025in in diameter and cracks up to 0.254mm / 0.01in wide by 12.7mm / 0.5in in length. As a rough guide, if you are adding coolant almost as fast as you are losing it, and the system is draining in around 15 minutes, then the leak is too severe for Green Demon to repair.

100% Guarantee

If for any reason Green Demon cannot repair your leak, or once it’s made a repair that leak ever returns, then we offer a 100% money back or product replacement guarantee.

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