On The Road

Pay close attention to fluid levels


Q: I read online that when the weather changes along with the seasons, it is a good time to check coolant and brake fluids. Is this really necessary, and why?

A: Yes. In fact, the fluids in your cooling system, power-steering system, automatic transmission and brake system are all products that go through temperature changes, have additive packages in them and are petroleum-based, just like your engine oil. Each fluid requires attention at regular intervals.

• Your engine coolant turns acidic as it ages. When this happens, it will cause damage to the engine and cooling system components. Coolant in good condition will be within the neutral range on the pH scale. A thorough service center will check coolant pH and recommend changes when needed before damage occurs.

• Brake system fluid collects both moisture from the environment and wear metal from the brake system itself. These contaminants cause damage and premature wear to the brake system components, so the fluid contamination level should be checked at service intervals and changed as needed. Modern-day vehicles can have brake system components costing as much as $3,000 to replace, so changing the fluid can save big money in repairs.

• Your power-steering system fluid breaks down over a period of time and picks up wear particles from the system hoses. Worn-out fluid causes premature wear in the system’s pump and steering rack. The hose debris will block the system’s small passageways. Changing this fluid when needed can also save thousands of dollars in repair costs.

• Automatic transmission fluid works especially hard in doing its job of connecting the engine to the drive train. It both lubricates and serves as a coupling agent in the transmission, and goes through a wide range of temperature changes every time the vehicle is driven. When this fluid breaks down, the result is premature wear of components inside the transmission. Transmission replacement or rebuilding can cost $3,000 and more, so change that fluid.

All the above fluids require monitoring and changing, and fluid replacement must be done in its entirety.

What is known as a “drain and refill” only replaces, on average, approximately 20 percent of the old fluid, as the fluid is present throughout the vehicle systems, not just in the fluid receptacle. Special equipment is needed to ensure a 100 percent fluid change, so don’t hesitate to ask if your service center has invested in such equipment and will perform the correct service for you.

Your vehicle’s fluids are its lifeblood.

If you can’t remember the last time you had them checked, it is definitely time, especially as winter approaches. Prolong your vehicle’s life and help avoid big repair bills by keeping those fluids healthy.

Warren McCord is an ASE-certified master technician and owner of Dean’s Automotive Inc., 2037 Old Middlefield Way, Mountain View. For more information, call 961-0302 or e-mail McCord at This email address is being protected from spambots. You need JavaScript enabled to view it..

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