keeping Coolant Clean

A survey of ASE-certified automotive technicians throughout th enation determined that coolant is the second most neglected vehicle maintenance item. Coolant should be checked for both strength and also pH level at each service. To check the pH level, you should use a chemically treated test strip, which can be purchased at most part stores.

The average pH level range of typical coolant is around 10.5. When diluted with water, it drops to 8.5 to 9. A pH level at 7 or lower can lead to both excessive corrosion and electrostatic discharge (ESD). With ESD, the PCM can receive false readings from the electronic cooant temperature sensor, which can lead to poor fuel economy and setting off of diagnostic trouble codes. With a low pH level, the coolant becomes acidic, which can cause hose, radiator and water pump failures.

So the bottom line is that if coolant is contaminated or the additives are depleted, flush the system. The use of low or no silicate coolant at a 50/50 ratio is best. You and your customer will be satisfied with a job well done.

Also, radiator caps play an important role on automotive cooling systems. They can lead to radiator or water pump seal damage. The job of the cap is to hold pressure on the system, which raises the boiling point of the coolant and prevents steam bubbles from forming inside the cooling system.

Caps should be pressure tested each time the system is serviced. Most caps will range from 4 psi to 18 psi.

When testing the cap, it should hold pressure for two minutes. If it doesn't the cap should be replaced. The condition of the gasket in the cap also should be inspected for swelling or tears that could lead to coolant loss and engine overheating.

Courtesy Airtex Automotive Division.