Easy tips

What causes pressure in the coolant system?

What causes pressure in the coolant system?

The answer is: heat. When you apply heat to a liquid or gas trapped in an enclosed space, it expands and creates pressure. The refrigerant in your car’s cooling system works in the same way.

How can you tell if coolant is leaking from Radiator?

Grasp the pressure tester and pump the plunger rapidly to build pressure inside the system, much like you are pumping air into a tire. You will notice the needle on the pressure tester gauge start moving upward as it measures the pressure inside the system. At this point you may see coolant leaking from the engine, radiator or hose.

Can a pressure test show a small leak?

A short term pressure test may not show a small leak. Doing the pressure test overnight may show signs of small leaks, but can still be difficult to find, (the pressure dropped but can’t find a leak). A blown head gasket may show up if the sparkplugs are removed and the system is pressurized. The coolant may collect in the cylinder bore.

How to pressure test an automotive engine cooling system?

It’s best to start with the engine cool and the car parked on dry ground so you can more easily see where the leak is coming from. If the cooling system is low or empty refill it with water before the test begins. Fill the system carefully as not to spill any water so it will be easier to detect the leak.

How does pressure testing indicate leaks from the coolant hoses?

A pipe can have a really small hole which only starts leaking when the system is fully hot and therefore at full pressure – it then can release cookant which effectively instantly vapourises and leaves very little trace – except for the scald on your forearm as you get close to it… and that is how I found it – pain is a good educator…

Why is my car leaking coolant?

The only two reasons your car could be leaking coolant is due to a part failure or an overfilled system. Coolant expands as it gets hot and flows from your vehicle’s radiator into the overflow tank. If the overflow tank is too full coolant will spill out of that reservoir and may look like a leak.

How do you find a radiator leak?

Check the radiator: Feel the underside of the radiator to see if it’s leaking, and look around your radiator for whitish deposits or rust-colored stains. These indicate old leaks that have dried, but they may not be all that old; water tends to evaporate quickly on a hot radiator.

What is the cooling system pressure?

Cooling system pressures are controlled by the radiator cap. Radiator caps hold pressures between 6-16 PSI for most automotive systems. Most cooling system pressure test kits come complete with everything you will need to pressure test most vehicles.

What is a radiator pressure test?

A radiator or cooling system pressure test is useful when finding a radiator leak or a blown head gasket. This tool attaches to the top or the radiator or coolant reservoir and enables air pressure to be pumped into the system including the engine block, cylinder heads, coolant hoses, heater core and radiator.

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Ruth Doyle