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Car and Truck Maintenance Services FAQs

Car and Truck Maintenance Services

Basic information that pertains to recommendations for maintenance services of cars, light trucks, vans, and SUVs
Includes preventive maintenance and OEM factory recommended scheduled maintenance
Always consult your vehicles owner manual as a minimum recommendation resource

Why do shops sometimes recommend a maintenance service at a lower mileages than my owner’s manual?
With many manufacturers using superior fluids and improved machining methods when building vehicle components, maintenance interval recommendations have been extended. Some of today’s cars have built in calculators that function to identify the mileage and turn on a “change oil” light when a service is due. In these cars and trucks, the indicator light usually comes on between 4,000 to 6,000 miles. This is a significant change from the previously recommended 3 month/3,000 mile interval that was accepted for years.

While some technicians continue to use the older interval when scheduling engine oil changes, others use additional criteria such as vehicle age, vehicle type, usage patterns, and maintenance history to make recommendations for a scheduled maintenance item.

If a repair shop or dealership recommends a fluid flush service that is not listed in my vehicle owner’s manual, what should I do?
Some repair technicians recommend a flush service for components in your car that use oil to lubricate and/or cool. They believe current evidence suggests a fluid flush will more completely remove dirty or degraded fluid and thus help extend the life of the components in your car, even though the manufacturer may NOT recommend this method for fluid replacement. Some manufacturers, like Honda, recommend against flushing and only approve the drain and fill method for changing fluids.

As a point of interest, many dealerships do offer flush services even though the manufacture does not recommend them. As a manufacturer dealership, they are allowed the autonomy to decide what services they sell.

Which method is better for transmission or coolant system services – a fluid flush or drain and fill?
As pointed out previously, many mechanics believe flushes are a better way to replace dirty fluid with clean. In this method, the machine pushes out most or all of the old fluid as it forces in the new fluid.

While drain and fill services have been used for years, it is difficult to verify that all of the dirty fluid has been removed. With some transmissions, for example, more than half of the fluid will remain in the system even after it is drained. The new fluid installed to replace what drained out will then mix with the dirty fluid that remained resulting in a degraded quality of the fluid overall. This is the reason some technicians consider a drain and fill less effective to prevent component wear and eventual failure.

What is the difference between a transmission fluid flush and a transmission service?
Some elements of this question are answered in the previous question. In general, a flush refers to exchanging fluid only. When a shop uses the term transmission “service” they are referring to removing the pan and frequently changing the filter. If the filter is not changed during a “service”, it may be more cost effective to do a flush.

Why is “flushing” important for power steering systems?
Power steering systems operate under extreme amounts of pressure. Over time, the metal components in this system experience wear that releases particles or fragments of metal. These particles are picked up by the circulating fluid which is designed to lubricate and prevent wear. Many steering systems have valves that open and close and small ports that can become clogged by metallic fragments. The metallic particles also act as an abrasive, damaging bearings, other internal parts.

As previously explained, flushing the fluid more completely removes the contaminated oil as the clean oil is forced in by the flushing machine. With more of the abrasive oil removed, the newly installed oil can once again effectively lubricate and thereby extend the life of the steering components.

Are cooling system flushes or fluid replacement still required on newer cars?
Many newer vehicles have coolants that the manufacturers say should last for 100,000 miles. Since coolant, like any fluid, breaks down over time, its lubricating, anti-corrosion qualities decrease. This is why some mechanics feel uncomfortable leaving coolant in for that length of time.

It is probably best to consult your owner’s manual for your vehicle and talk with your mechanic. Then make your best decision about cooling system flushes or fluid replacement.

When should the oil be replaced in truck front & rear differentials?
Again, consult your owner’s manual for factory recommendations. If your truck is used to pull a trailer or haul heavy loads, your mechanic may recommend servicing the oil more frequently than your manual.

Do I need to have my fuel system or fuel injectors cleaned?
Many manufacturers don’t recommend cleaning fuel systems or injectors as a scheduled maintenance item. A quick answer to this question is difficult because there many variables to be considered when making this decision, such as,

  • age of the vehicle
  • make of vehicle
  • conditions under which the car usually operates
  • type of fuel usually purchased

If, however, you are reporting a specific problem related to the fuel system, your repair shop technician may recommend this service to correct it.

Are brake fluid flushes really necessary?
Like power steering systems discussed above, your brakes operate under very high pressures and temperatures. The fluid will degrade over time with normal use. The fluid can also become contaminated by moisture or adding the wrong fluid type to the system. This is one of those services that manufacturers probably don’t recommend but repair shop may recommend as a smart, preventive maintenance item.

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