Engine Coolant Leak Testing with Pressure, Dye and Chemical Block Testers.

There are many ways to diagnose, find and fix a water leak on a vehicle, but a technicians experience in using the correct tools is absolutely paramount to a correct diagnosis and repair. we use all the best methods and tools, some of which are mentioned below.

 

Cooling System Pressure Tester.

A cooling system pressure tester is a device that allows us to test the whole cooling system including radiator, pipes and expansion tanks for leakage by testing the ability to hold at the correct pressure.

On the header tank or radiator cap a pressure will be indicated, such as 14 pounds. Affixing the tool to the opening and squeezing the hand pump up to the 14psi mark and waiting allows us to see if there is the possibility for a leak. If the pressure holds steady for at least 10 minutes, there is a good chance there is no leak. However if the pressure drops bit by bit there is likely a leak and we can increase pressure further to try and pinpoint this leak as, under pressure, it will usually leak faster and therefore be easier to pinpoint.

 

Block Tester (or Combustion Leak Tester)

This is a tool and chemical used to find pretty much any coolant leak or seep in a head gasket joint between block and head. This device is essentially a tube that is filled with a green testing chemical that reacts only with combustion gasses.

This sampling tube is affixed to the vehicles expansion tank in place of the cap and coolant is drawn out of the tank into a bulb that contains the chemical. This chemical turns to another colour in order to indicate the presence of combustion gasses.

If the colour remains as it was, IE: Blue, then no combustion gas is present in the coolant.
The presence of combustion gases within the cooling system indicates a head gasket failure or other crack that has compromised the barrier between engine cylinder and coolant.

Leak Detection Dye.

Leak detection dye is simply another chemical that is safe to add to the coolant itself to make leaks easier to see. These dyes may be fluorescent and glow under exposure to UV lights. This certainly makes detection of smaller and harder to spot leaks much easier as they glow under our test light.