Niagara Gazette

November 14, 2013

TOM'S CORNER: Severe and normal service recommendations for fluids in your car

By Tom Torbjornsen
Niagara Gazette

Niagara Gazette — I often discuss when to change the oil in your vehicle, but this article is about the other fluids that need to be serviced. However, first we need to distinguish between severe and normal service applications.

Severe Service Application

Follow the SEVERE schedule (which is more aggressive) if any one of the following are true for you:

• Most trips are less than 5 to 10 miles (8 to 16 km). This is particularly important when outside temperatures are below freezing

• Most trips include extensive idling (such as frequent driving in stop and go traffic)

• The vehicle is operated in dusty areas frequently

• Trailer towing or using a carrier on top of the vehicle frequently

• The vehicle is used for delivery service, police, taxi or other commercial applications

Normal Service Application

Follow the NORMAL schedule only if none of the conditions from the SEVERE schedule apply.

Carmakers vary on their recommendations for severe or normal service schedules based on applications, so make sure you check your owner’s manual for the recommended fluid/lubricant/filter change interval according to your particular use of the vehicle. Some of the items I cover in this article may not be listed in your service schedule so consider following the service recommendations I suggest in this article.

You drive under normal operating conditions if you:

• Drive the vehicle at least 20 miles a day at highway speeds

• Operate the engine long enough to thoroughly warm it up along with all the other drivetrain/powertrain components

• Seldom haul heavy loads or tow with the vehicle

• Operate the vehicle at highway speeds in a clean environment

Transmission fluid

The transmission fluid performs a few functions. It serves as a medium by which the hydraulic pressure, necessary to operate the transmission is created. It absorbs heat within the unit and carries it away to the transmission oil cooler insuring that the trans does not overheat. It lubricates the moving parts inside the trans. Finally; it keeps dirt in suspension until the trans filter filters it out. The trans fluid is oil and therefore subject to viscosity breakdown and loss of protective, lubricating & cooling properties. Leaving the transmission to operate on fluid that is worn out will result in premature transmission wear and failure.

Follow the Severe Service application if you tow a trailer, drive frequently in stop-and-go traffic, drive off-road on a regular basis, idle long periods of time, use a snow plow, haul heavy loads and load the vehicle frequently. Following a vigorous maintenance schedule will circumvent internal wear, friction and heat ... all killers of transmissions.

Follow the Normal Service application if you drive at least 20 miles each day at highway speeds, never or rarely load the vehicle, do not tow trailers or use snowplows. Bottom line? Moderate driving.

Differential and transfer case lubricants

Differentials and transfer cases are gearboxes. The differentials turn the axles that turn the wheels. The transfer case is an auxiliary gearbox that allows a four-wheel drive vehicle to shift from low to high range and back again. Each of these gear boxes house lubricant to keep them running smoothly and cool. Lubricant that has metal flakes in it indicates internal wear of the component. The unit should be opened up and inspected for internal wear. Fluid that is black has been overheated and the unit should be inspected for the cause of the overheating, (usually wear). Fluid that is milky in color has been contaminated with water and should be changed immediately to avert premature failure of the unit.

Also check for open or broken vents that allowed the water in and repair. Carmakers use specially formulated lubricants in many of these units unlike days of old when all a differential or transfer cases ever used was 90W gear oil. Make sure you check your owner’s manual for fluid specifications before adding any lubricants yourself.

Follow the Severe Service application if you tow a trailer, drive frequently in stop-and-go traffic, drive off-road on a regular basis, use a snow plow, haul heavy loads and load the vehicle frequently. Following a vigorous maintenance schedule will circumvent internal wear, friction and heat ... all killers of differentials and transfer cases.

Follow the Normal Service application if you drive at least 20 miles each day at highway speeds, never go off-road, never or rarely load or work the vehicle and/or do not tow trailers or use snowplows.

Engine coolant

Engine coolant courses through the cooling system of the engine absorbing and transferring heat from the engine’s combustion chambers to the radiator where it is cooled and re-circulated back into the engine to repeat the process. Engine coolant has formulated into it chemical packages that inhibit rust & scale buildup, lubricate water pumps, protect against freeze up and absorb heat from the engine to transfer it to the radiator to where the heat is dissipated. Leaving the engine coolant in the engine too long, operating the engine in an overheated condition and/or working the engine extremely hard can and does result in breakdown of the coolant’s chemical properties, thus leaving the engine unprotected from freeze up, allowing rust & scale buildup in the cooling system, excessive friction & wear of the water pump and ineffective engine cooling.

Follow the Severe Service application if you tow a trailer, drive frequently in stop-and-go traffic, idle long periods of time, use a snow plow, haul heavy loads and load the vehicle frequently, drive off-road regularly, essentially you work the vehicle hard. All these conditions contribute to engine coolant breakdown and thus loss of cooling system protection for your engine.

Follow the Normal Service application if you drive at least 20 miles each day at highway speeds, always warm the engine to operating temperature, never or rarely load the vehicle, never go off-road or do not tow trailers or use snowplows.

Power steering fluid

Power steering fluid is the medium by which power assisted steering is achieved. The system consists of a pump and fluid reservoir, lines and a power steering gear. The pump creates hydraulic pressure from pumping the fluid, which hydraulically powers the steering gear making steering a vehicle easy for anyone, regardless of his or her stature & strength. On most vehicles, power steering fluid does not show up in the maintenance schedule and thus there are no severe or normal service recommendations for power steering fluid, the only suggestion I have here is to check it every oil change, inspecting closely for evidence of metal flakes indicating steering gear or pump wear or a black or dark color indicating overheating of the fluid and thus need for replacement and system inspection.

If the fluid appears to be overheated, check the pump for internal wear, as a worn pump is usually the cause for overheating of the power steering fluid. If you catch the pump early enough and replace it, you usually circumvent replacing the steering gear later due to wear from ground metal circulating through it from the worn pump.

Brake fluid

Brake fluid is a hydraulic fluid used as a medium to generate the hydraulic pressure needed to activate the braking system of your vehicle. When you press the brake pedal, the master cylinder, much like a pump, sends fluid coursing through the system applying your brakes. On most vehicles, brake fluid does not show up in the maintenance schedule and thus, there are no severe or normal service recommendations for brake fluid. The only suggestion I have here is to check it every oil change, inspecting closely for proper level, color and/or evidence of rust sediment, indicating that moisture has contaminated the brake fluid.

Brake fluid that is black in color has been overheated, usually due to a brake caliper that has stuck in the applied position from rusted slides or a stuck piston in the caliper bore, if this is evident, check the system for evidence of conditions afore mentioned. If you live in a state where you experience winter or a lot of rain, keep a close eye on brake fluid every oil change because brake fluid is hydroscopic in nature, that is it absorbs moisture and if the system is not properly sealed from the environment, it will absorb moisture and develop rust and sediment buildup, impeding brake performance.

‘Til next time ... Keep Rollin’.

“America’s Car Show” with Tom Torbjornsen airs 7:30 p.m. Wednesday, 9 a.m. Thursday and 11 a.m. Saturday on WBBZ-TV.

"America's Car Show" with Tom Torbjornsen airs 7:30 p.m. Wednesday, 9 a.m. Thursday and 11 a.m. Saturday on WBBZ-TV.