Car's General Maintenance

Table Of Contents

General maintenance may be one of the most applicable for the average person to care for his or her own vehicle. We’ll discuss the vehicle owner’s manual, vehicle fluids, fuses, belts and hoses, vehicle lighting, and the air filter.

Vehicle Owner's Manual

All vehicles are different and the owner’s manual for each make and model is the most useful reference for the maintenance and repair of that specific vehicle. Despite the fact that it can often look thick, complicated, and boring on the surface, vehicle owners should become familiar and comfortable with the owner’s manual. They’re not so bad once they’re finally opened. Almost any topic regarding your vehicle’s maintenance can be found in the index.

Owner’s Manual

The owner’s manual will have a maintenance chart. The chart will include such information as when to change the oil, rotate tires, replace the air filter, inspect the fuel cap and lines, change other fluids (transmission fluid, etc.), and other maintenance issues. Your vehicle may have different maintenance requirements at 30,000 miles, 90,000 miles, 150,000 miles, and at other intervals as indicated specifically in your owner’s manual.

Being familiar with the maintenance chart in your owner’s manual can help you save money when taking your car to the mechanic for maintenance checks. Sometimes the repair shop will suggest additional services that aren’t necessary.

If you don’t have the owner’s manual for your car then you may be able to find one online by using Google or another search engine. Search the website for the make of the vehicle. You could also try your local library.

Vehicle Fluids:

Vehicle fluids include brake fluid, engine oil, coolant, power steering fluid, windshield washer fluid, transmission fluid, and battery fluid. Fluid level information and the location of each fluid reservoir can be found in the owner’s manual for your particular vehicle. 

Brake Fluid: On most vehicles the reservoir for brake fluid is clear. You can check the fluid without removing the cap. There will be a marking on the reservoir that indicates the minimum and maximum levels. You’ll want to make sure that the level is between those two marks. This fluid should never need to be topped off during maintenance. Low fluid is an indication of a problem. If the fluid is low then you may want to bring it to a mechanic, depending on your own skill level. Most vehicles have a dashboard light that illuminates when the brake fluid is low.

A brake fluid reservoir. Notice the MAX and MIN markings.

Engine Oil: Engine oil should be checked each time the vehicle is refueled (i.e. each time you go to the gas station). Most engines, but not all, have a dipstick to indicate the oil level. Typically the handle is yellow. Follow these steps to check the oil:

· Turn the engine off.

  • Remove the dipstick.

· Wipe off the end of the dipstick with a rag or paper towel.

· Put the dipstick back in.

· Take it out to look at the level at the tip

The stick will have marks on it. The “add” mark typically indicates one quart low. If an engine is leaking oil then the price of repairs can vary depending on which repair is needed and the make and model of the vehicle.

Oil dipstick (above) and oil level on a dipstick (below)

Coolant : Never open the cooling system if the engine is hot . If you’ve just been driving then don’t open it. After you think the engine has cooled then you can lightly touch the radiator cap to test it. If it’s still hot, then don’t open it. Opening the radiator cap while the engine is still hot can shoot a six-foot geyser into the air and burn any skin it contacts. The best time to check the coolant is in the morning before the car is driven.

Coolant. Notice the green color; coolant can actually be any color (pink, orange, transparent, red, etc.)

A low coolant level indicates a possible leak which should be investigated. A very small amount of evaporation of coolant can occur over time. As a rule, if you need more than one quart of coolant, that indicates a problem.

If the coolant is low then it needs to be replenished with the proper type of coolant and mixture. Consult the owner’s manual for the proper type of coolant. The proper mixture is a 50/50 ratio of coolant and distilled water. It is important to use distilled water because the impurities in other water would circulate through the system and ruin the system over time. Coolant can be purchased pre-mixed in a 50/50 solution if desired.

50/50 pre-diluted coolant. 

Power Steering Fluid: There may be a clear reservoir for power steering fluid. If there is, then it can be checked the same way as the brake fluid described above. If the power steering fluid is not in a clear reservoir then it will have a dipstick. Refer to the owner’s manual for the location of the reservoir and the type of fluid that should be used. Low power steering fluid is an indication of a leak and it should be investigated. At that point, the driver may also notice changes in steering performance.

Power steering reservoir (black tank). Notice how the cap is labeled.

Windshield Washer Fluid . There may be a clear reservoir or a dipstick for windshield washer fluid. Refer to the owner’s manual for the location. If you live or travel in cold climates, below 32 degrees, you need to make sure that you use washer fluid with antifreeze.

Windshield washer fluid

Transmission Fluid . Refer to the owner’s manual for the location of the transmission fluid. Some vehicles have a dipstick but many new vehicles do not have one. In some vehicles you have to go underneath the vehicle to check this fluid. If the fluid is low, then there is a leak and it should be investigated. The fluid should also be red. If it is black and/or has a burnt smell then there is a problem with the transmission.

New transmission fluid, red in color

Battery Fluid and Terminals: If the battery is clear then you can look at the level of the fluid. Most modern vehicles do not have clear batteries. Any corrosion or signs of leaks around the battery are indications of a problem. Corrosion can be a green or white powdery substance. Don’t ever allow corrosion to come in contact with the skin or eyes because this is an acid and it will burn. If corrosion is present at all, the battery may need to be replaced or there could be a problem with the charging system. Excessive discharging of the battery without the engine running (i.e. listening to the radio, keeping the cab lights on or using any accessory with the engine off) can cause the battery to overheat, which leads to early battery failure and leakage of battery acid. If the battery fluid is low, only use distilled water to refill it. Never add acid to a battery.

The presence of corrosion indicates a problem that should be addressed. However, as a temporary fix, you can clean off the corrosion to get the car started. Start by rinsing off the corrosion with the garden hose. Then disconnect the terminals starting with the negative terminal first, then the positive terminal. Use a mixture of baking soda and water or battery terminal cleaner to rinse off the terminals and battery posts. You’ll see the baking soda reacting with the corrosion to form fizz and bubbles. Use a wire brush or scraper (depending on the type of terminal) to clean the inside of the terminal and battery posts. Then rinse again with more water. Once the terminals and battery posts are clean, reattach the terminals starting with the positive terminal first, then the negative terminal. It is not sufficient just to clean off the corrosion. Again, the presence of corrosion indicates a problem that should be addressed.

Car battery


Consult the owner’s manual to locate the fuse boxes in your vehicle. They can be anywhere in the vehicle. Modern vehicles use blade-type fuses. The part of the fuse that you’ll see initially is plastic and color-coded. When the fuse is removed it can have a similar shape to a square letter “C” with the arms of the “C” being metal and the back of the “C” being the color-coded plastic. The color coding system for fuses has been used since the early 1980s. Older fuses are made of glass tubes. The color coding for modern fuses is universal and indicates the amperage of the fuse.

Violet – 3 Amp Pink – 4 Amp Orange - 5 Amp Red - 10 Amp Blue - 15 Amp Yellow - 20 Amp Clear - 25 Amp Green - 30 Amp Orange – 40 Amp (and many others)

Blade-type fuses are used in modern vehicles. Most of them have a “C” shape (or “E” shape, facing down in the image). In a blown fuse, the “S” or upside down “V”s in the middle will be broken (called the element). The image shows the top view of each fuse just above each side view; notice that each top has metal contacts that are not covered by colored plastic.

Image credit: CC-BY-SA-Havarhen on Wikipedia.

Glass tube fuse used in older vehicles Image credit: CC-BY-SA-Aka on Wikipedia

There are two ways to test the fuse: one is by removing the fuse to look at it and the other is to use a test light.

When testing it by removing it, simply pull it directly out and look through the color-coded plastic to see if the element (connection in the center) is intact. If it’s open, then the fuse is burnt out. Sometimes you’ll also see a black singe that makes the transparent plastic more opaque. Never remove more than one fuse at a time. This helps to keep track of where the fuse was pulled from and permits easy replacement of the fuse in the correct place. If multiple fuses happen to get pulled at the same time then the size and placement of each fuse can be found in the owner’s manual.

An easier and faster way to test the fuses is with a testing light since the fuses don’t have to be removed. The testing light looks like an electric screwdriver with a pointed tip. The wire end or black end of the testing light must be grounded to a clean, unpainted metal surface of the vehicle. If you can’t find a place on the body of the vehicle, then you can always ground it to the negative terminal of the battery. The point of the testing light is placed on the metal contacts of the fuse. There is a metal contact on each side of the fuse’s color-coded plastic (on the back of the “C”). Upon contact the display will indicate if the fuse is still good.

Test light

Not all fuses have power all the time. So the test should be performed with the key turned to the “on” position in the ignition and the headlights turned on (the engine does not need to be running). Even with the key and headlights turned on, there is one other fuse that will not have power, which is the crank fuse. The crank fuse only has power when the key is turned to the crank position while starting the engine. This particular fuse does not need to be tested unless the vehicle won’t crank.

Belts & Hoses

Two hoses and a belt are seen in this image

If a belt squeals after starting the engine or while driving then this indicates a problem with belt tension. Most modern vehicles have automatic belt tensioners which keep the belt at the appropriate tension. Checking the belt tension varies by make and model.

Modern vehicles only have one belt, but older vehicles have an individual belt for each accessory of the engine (i.e. power steering, air conditioning, and alternator). Consult a workshop manual for the proper methods for checking belt tension. (The workshop manual or service manual is different from the owner’s manual and may be found at the local public library or ordered online). Belts can also be checked by visual inspection and touch for signs of cracking, fraying, or glazing. Glazing means the drive surface of the belt will be shiny.

Hoses can be checked visually and by touch for signs of cracking, swelling, or leaks. If the engine is cool, then squeeze the hose to check for softness. If there is any variation from the hose to hose within the same vehicle then that could indicate a problem.

A cooling system pressure tester can be a valuable tool to pressurize the cooling system and check for leaks or swollen hoses. This tool is rented from an auto parts store and should come with instructions for use. You’ll attach it in place of the radiator cap and hand-pump it as you watch the gauge. Never exceed the indicated pressure that is written on the top of the radiator cap. Most modern cars have a limit of 16 psi. Again, do not open the radiator cap if the engine is still hot. 

Vehicle Lighting

Vehicle lighting includes instrument panel lighting, warning indicator lights, left and right turn signals, brake lights, hazard lights (which have a distinct circuit from the turn signals even though the display is in the same place), headlights and tail lights, front marker lights, the license plate light, and lights for the cab and trunk. Checking vehicle lighting goes quicker and smoother with two people, and in the case of the brake lights two people are required.

The instrument lighting is all of the backlighting for the instrument cluster (all the gauges, speedometer, fuel gauge, and others). The instrument lighting can be checked by turning on the headlights at night or in a dim garage. Check to see that all the gauges are clearly visible. There should not be any dark spots on the cluster.

Dashboard showing gauges and warning indicator lights 

The warning indicator lights on the dashboard include the brake light, oil light, check engine light, anti-lock brake (ABS) light, airbag light, tire pressure monitor, engine temperature light, and others -- all of which can be found in the owner’s manual. All of the warning indicator lights will turn on for a set amount of time (about a minute, but varies per vehicle) when you turn the key to the “on” position without cranking the engine. Once the engine is running, none of these lights should be on (even the seat belt light should be off, indicating that you’re wearing your seat belt). If one is on, then it indicates a problem with its correlating system. The number of lights and types of lights will vary by make and model. Some vehicles have features that others don’t, such as traction control. 

Exterior lighting is checked with the key turned to the “on” position in the ignition (or with the engine running, but it’s not necessary to have the engine running just to check the lights). Turn on the headlights. Check all four corners of the vehicle. On both sides (right and left, or driver side and passenger side) the same number of bulbs should be illuminated. There should be two front marker lights that are orange, two tail lights, and a license plate light.

Rear lights of a vehicle with the brake lights illuminated.

Turn the left turn signal on. Check the left front and left rear of the vehicle for blinking lights. Some vehicles have more than one bulb for the turn signal and some even include a signal in the side rearview mirrors. Be sure every applicable bulb is illuminating. Some vehicles have a cornering lamp, which is a clear lamp on the front of the vehicle which illuminates corners while turning. This should be illuminated but it will not blink.

Turn the right turn signal on. Check the right front and right rear of the vehicle for blinking lights. Be sure all applicable bulbs are illuminating. Check the cornering lamp if applicable.

When the turn signal is on and the indicator is blinking fast or not blinking at all, these are indicators of a failed bulb.

Brake lights require two people for inspection. One person presses the brake pedal while the other person checks the rear of the vehicle to make sure all the brake lights are illuminating, including the high-mount brake light in the rear window if the vehicle is equipped with one.

Activate the hazard switch. Check to make sure that there are flashing lights with an equal number of bulbs on all four corners. The hazard lights are wired separately from the turn signals, so it is important to check the hazard lights even if the turn signals have been checked.

Air Filter

Consult the owner’s manual for the location of the air filter. Remove the air filter. Inspect for visual signs of dirt and debris. Hold the filter up to fluorescent light; you should be able to see light coming through the filter. If there is any doubt then change it. It’s cheap preventative maintenance and it helps preserve fuel economy. 

Various air filters.

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