USING A COMBUSTION LEAK DETECTOR
A failed head gasket, flawed cylinder head or cylinder defects usually show signs. The engine will overheat, the coolant level may drop abnormally (sometimes without obvious external leaks), steam may come from the exhaust from coolant entering the combustion chamber or the cooling-system pressure cap will release excess pressure from engine compression entering the cooling system. The signs aren’t always clear, but serious engine problems definitely require extensive engine repairs that will be expensive if you’re not prepared to do the work yourself. Before you tear apart an engine or pay a shop to do it, using a combustion leak detector can confirm if a head gasket, cylinder head or cylinder is defective.
HOW DOES A COMBUSTION LEAK DETECTOR WORK?
A failed head gasket, flawed cylinder head or defective cylinder(s) allow combustion chamber gases to enter the cooling system. The combustion leak detector uses a color-changing fluid that reacts to combustion gases to indicate the presence of combustion gases in the cooling system.
WHAT CAUSES COMBUSTION LEAKS?
An engine overheating from coolant leaks or clogged radiators is a common cause of head gasket failure. Head gaskets, cylinder heads and cylinders damaged during repairs can also cause combustion leaks. In rare cases, defective head gaskets, cylinder heads or cylinders cause leaks.
Get the leak detector. Combustion leak detectors use a chamber that mixes a sample of gases drawn from the cooling system with color-changing fluid to confirm head gasket, cylinder head and cylinder leaks. Harbor Freight has a kit for $24.99, and you can borrow the tool from some auto-parts chain stores.
Get uncontaminated test fluid. Leak detector kits don’t come with the color-changing test fluid needed to do the test. Harbor Freight and some auto-parts stores sell the test fluid for $9.99. Make sure the fluid is blue before you buy it. It turns yellow or green when exposed to combustion gases and is easily contaminated.
Locate the fill line for the test fluid on the leak detector. Remove the squeeze bulb from the top of the leak detector, add test fluid to the fill line and replace the squeeze bulb with the metal check valve facing out.
Perform the test. Park your machine in a well-ventilated area. Remove the pressure-relief cap from the radiator or coolant recovery bottle. The coolant level must be 2–3 inches below the radiator or recovery bottle opening to prevent coolant from touching or entering the leak detector and contaminating the test fluid. Draw off coolant if needed. Set the parking brake and/or put the transmission in park, start the engine and let it reach normal operating temperature with the thermostat open. Press the cone-shaped end of the leak detector into the radiator or coolant recovery bottle opening so it seals well. With the engine idling, squeeze and release the bulb for one minute to draw radiator gases through the test fluid. Note the color of the fluid. If the fluid turns yellow, it indicates a combustion leak. If the fluid remains blue, no leak is present. If no repairs are needed, add coolant to the proper level and replace the pressure cap.
See UTV Action’s test of Boyesen’s Supercooler high performance water pump here: BOYESEN SUPERCOOLER PERFORMANCE WATER PUMP – UTV Action Magazine