Diedrick’s Automotive wants to help you lower your cost of driving. One of the best ways to do that is through maintenance. Use this guide to help understand what maintenance is and why it is so important.
Maintenance is the replacement of parts and performing service work to greatly reduce the chance of more expensive items failing. For instance, coolant is replaced to prevent damage to engines, radiators and heater cores. The cost to replace the coolant is a small fraction of the cost of the repairs it prevents.
Normal Service as defined by most manufactures is rarely the way vehicle owners drive. It is described as regular driving of longer trips over 15 miles at highway speeds with little to no stop and go driving. Under these driving conditions the normal service schedule is okay.
Severe Service as defined by most manufactures is more likely how most people drive. As an example, any of the following items would be considered severe service driving.
- Most driving is stop and go.
- Most daily driving is less than five miles one way.
- High temperatures above 90′ F.
- Low temperatures below 0′ F.
If your driving includes any of the above conditions it is better to follow the manufacture’s severe service schedule.
- Accessory Belts
- Air Conditioning
- Air Filter
- Automatic Transmission Service
- Brake Fluid
- Cabin Air Filter
- Differential Fluid
- Fuel Filter
- Manual Transmission Fluid
- PCV Valve
- Power Steering Fluid
- Spark Plugs
- Timing Belt
- Transfer Case Fluid (4 wheel drive only)
- Wheel Bearings
1. Accessory Belts
Belts are used to drive accessories on the engine (alternator, power steering, air conditioning, etc.) Most vehicles use serpentine belts in place of the V-belts that were used years ago. Serpentine belts last longer and work better than V-belts but they still need to be replaced.
Belts that are cracked, glazed, or frayed need replacement, they can break and cause engine damage or leave you stranded along the side of the road.
Under normal conditions accessory belts last between 50,000 and 60,000 miles or 4 years.
2. Air Conditioning
Air conditioning is not usually considered a maintenance item, but cleaning the air conditioning condenser can extend the life of the system. Condensers are exposed to air flow any time the vehicle is being driven. They collect bugs, leaves, dirt and dust. Hosing the dirt and debris from the condenser may help lower pressures and increase efficiency. The best time to clean the condenser is in the spring before the temperatures get hot.
3. Air Filter
We are all familiar with the engine burning fuel. Engines also use air, in fact they use 14.7 times more air than fuel. Even air that looks clean contains a lot of minute dust particles. The air filter’s job is to remove those particles before they enter the engine. Over time the air filter becomes restricted from this dirt. When this happens the engine looses power. Contrary to common belief even a badly restricted air filter will not reduce fuel mileage.
It is best to use a good quality air filter. Cheap air filters may not fit correctly and may have poor filter media. These faults can increase engine wear and damage mass air flow sensors. The length of the life of the air filter depends on the amount of dust in the air that flows through it. In very dusty areas the filter may become restricted in as little as 5,000 miles. Under normal conditions the filter should last 30,000 to 50,000 miles. Some vehicles have indicators on the filter housing which can be used as a guide. Care must be taken when the filter is replaced. Dirt can fall off the filter and may be drawn into the engine. Being careless when replacing the filter may cause more problems than the old dirty air filter.
4. Automatic Transmission Service
Automatic transmissions produce debris as part of their normal operation. Metal particles and clutch material is worn from the clutch surfaces and circulate with the fluid until the filter removes them. The fluid also deteriorates over time from exposure to heat and normal use.
Most automatic transmissions have a removable filter. With proper service the pan is removed, fluid drained and the filter is replaced.
We recommend this service be performed at three years or 50,000 miles whichever occurs first. On some older vehicles replacement of the internal filter requires disassembly of the transmission. On these vehicles the service is performed by draining and filling the unit twice in succession.
Batteries are rarely thought of as a maintenance item. Most people wait for the battery to fail before replacing them. This can leave you in an inconvenient situation as well as over work the charging system. Most batteries die between four and five years old. Some die suddenly and can leave the vehicle stranded. Others die slowly and cause the alternator and starter to work harder.
Since all batteries die, it is more convenient to replace them before this happens. Four years old is a good safe guideline in Wisconsin. Some batteries may last longer but their low cost and unpredictability makes it unwise to rely on an old battery.
6. Brake Fluid
Most brake fluid used in today’s vehicles is made of alcohol. Alcohol absorbs moisture from the air. The moisture in the brake fluid lowers the boiling point and increases damage done by corrosion. This happens whether the vehicle is driven or not. Because of this time is a better indicator of when to change instead of how much the vehicle is driven.
The color of the brake fluid is not a good indication of the condition of the brake fluid. Some fluids that appear clear or honey colored may be contaminated and fluid that appears dark may still be in good condition. A refractometer is used to test the moisture content of brake fluid.
7. Cabin Air Filter
The cabin air filter is used to filter the air that enters the vehicle through the heating and air conditioning system. This filter is just like the filter used in your furnace and air conditioner at home. It removed the dirt and dust from the air before it enters the vehicle. A restricted filter will reduce the amount of air from the heater or air conditioner which will make it take longer to cool or heat the passenger compartment.
Not all vehicles are equipped with cabin air filters but many are. They are normally replaced every 15,000 miles or once a year.
Antifreeze or coolant, performs several jobs. To work properly antifreeze is mixed half water half coolant. The 50/50 mix gives a freeze protection of around -35′ Fahrenheit. Coolant also provides corrosion protection.
There are several different types of engine coolant. Each manufacture has their own type of antifreeze. It is important not to mix the different types, they are not compatible with each other.
Over time the corrosion inhibitors are depleted. As the coolant ages the pH falls and the coolant becomes acidic which can cause severe damage. The freeze protection is also lost over time.
The interval to replace coolant depends more on time than miles. The coolant should be replaced every two to three years, when the pH approaches 7.0 or when the freeze point drops below the recommended temperature for your location.
9. Differential Fluid
Differential fluid lubricates the bearings, gears and, if the differential is a locking type, the clutches of the locking mechanism. A differential transmits the power to the drive wheels. To allow for expansion and contraction during the heating and cooling of the differential the differential is vented. This vent allows moist air to enter. Over time the moisture contaminates the fluid. The fluid lubricates, cools and cleans the gears and bearings, it also suspends any moisture that enters the differential.
Over time the differential fluid breaks down and needs to be replaced. On many front wheel drive vehicles the differential is part of the transmission. It is lubricated by the transmission fluid and is serviced as part of the transmission. On rear wheel or all wheel drive vehicles and some front wheel drive vehicles there is a separate differential which needs to be serviced separately. This service should be performed at about 50,000 miles. Under severe service such as towing it may be as low as 15,000 miles.
10. Fuel Filter
The fuel filter does exactly as it’s name implies, it filters the fuel. Dirt and other impurities enter the fuel during shipping and in the tanks at the gas stations. They can also be from rusted or deteriorate fuel tanks in vehicles.
It only takes a very small amount of dirt to ruin fuel injectors and even damage an engine. Fuel filters should be replaced at about 50,000 miles unless they are mounted in the fuel tank. Fuel filters that are in the fuel tank are normally good for the life of the vehicles.
Fuel filters should be replaced when there is a fuel system problem such as a fuel pump failure or if contaminated fuel gets into the fuel system.
Coolant hoses have been improved over the last 5 to 10 years. A lot of hoses last ten years or more. The hoses that come on the vehicle may be better than the replacements that are available.
The high quality original hoses on today’s cars should be regularly inspected and replaced only when needed. The first inspection should be done when the vehicle is three years old and then every year after. The hoses should be replaced when they are found to be soft, swollen, hardened, cut or frayed.
There are other hoses found on the vehicle. These hoses are for the air conditioner, power steering, transmission cooler and engine oil cooler. These hoses should be inspected and replaced as needed instead of at specific time intervals.
12. Manual Transmission Fluid
The lubricant used in a manual transmission gets dirty, absorbs moisture and the additives wear out over time. Contaminates are produced by the gears, bushings and moving components. Manual transmissions rately contain filters and replacing the fluid is the only way to remove contamination and replenish the additives.
As a general rule we recommend manual transmission fluid replacement between 50,000 and 75,000 miles, more often when towing. Transmissions use many different types of lubricants today so it is important to check for the proper type before replacing the transmission fluid.
13. PCV Valve
The positive crankcase ventilation or PCV valve, removes vapors and pressure that is generated in the engine. Over time the PCV valve may get dirty and plug up. When this happens pressure may start to build inside the engine. Pressure buildup can damage oil seals and gaskets. This may cause oil leaks and engine damage.
Under normal use the PCV valve should be replaced about every 50,000 to 75,000 miles but can fail as often as 40,000 miles. They should also be tested whenever engine work is performed and replaced sooner as needed.
14. Power Steering Fluid
Power steering fluid comes in several different types. Some vehicles use automatic transmission fluid and still others a vehicle-specific fluid. Power steering fluid acts as a lubricant, cleaner, seal conditioner and coolant for the system.
Like most fluids, in time, power steering fluid loses the properties that help it to work. It also becomes contaminated over time and since most systems do not have a filter, it must be replaced. Replacing power steering fluid between 50,000 and 75,000 miles is usually sufficient, unless the manufacturer recommends it sooner.
15. Spark Plugs
Spark plugs provide a small (0.030″ – 0.900″) gap that electricity jumps across. This spark ignites the compressed fuel-air mixture. Spark plugs are exposed to high voltage and the high temperatures found in the engine cylinder. The combination of extreme heat and high voltage cause the electrodes to wear. As they wear the gap gets wider and the plugs no longer work as efficiently.
Depending on the construction of the spark plug, they wear out between 30,000 and 100,000 miles. Standard spark plugs wear out closer to the lower mileage and platinum and iridium plugs closer to the higher mileage.
Spark plugs wear out in other ways than just the gap. They can become fouled with gas or oil, and the electrodes may become covered with foreign material. They can also leak between the ceramic and the metal base.
16. Timing Belt
Many engines have an internal timing belt. This belt is different from the external accessory or serpentine belt. The timing belt drives the camshaft(s) and sometimes the water pump and cannot be easily inspected. There are specific recommendations by the manufacturers for timing belt replacement. Timing belt replacement is normally recommended between 60,000 and 105,000 miles.
Because access to the timing belt is difficult, other items in the area of the timing belt are often replaced with the timing belt. The belt idler pulley(s), front crankshaft and camshaft seal(s), water pump, etc. may be recommended. The reason for this is that these other parts do fail and may damage the timing belt, resulting in expensive engine damage. The cost to replace these parts is much less if done when the timing belt is being replaced.
There is a great deal of price difference, between a complete job and merely replacing the belt. It is important to know exactly what is being charged for when replacing a timing belt.
Tires wear out over time. and the tread becomes thin. Tires also have a life expectancy of six-years. Not only does the tread wear down but as the tires age, the adhesives that holds them together as well as the rubber and other materials they are constructed of deteriorates. When this happens, they can separate and blow out.
Sean Kane, president of Safety Research & Strategies, Inc., compares an aging tire to an old rubber band. “If you take a rubber band that’s been sitting around a long time and stretch it, you will start to see cracks in the rubber,” says Kane, whose organization is involved in research, analysis and advocacy on safety matters for the public and clients including attorneys, engineering firms, supplier companies, media and government.
That’s essentially what happens to a tire that’s put on a vehicle and driven. Cracks in the rubber begin to develop over time. They may appear on the surface and inside the tire as well. This cracking can eventually cause the steel belts in the tread to separate from the rest of the tire. Improper maintenance and heat accelerate the process.
Every tire that’s on the road long enough will succumb to age. Tires that are rated for higher mileage have “anti-ozinant” chemical compounds built into the rubber that will slow the aging process, but nothing stops the effects of time on rubber, says Doug Gervin, Michelin’s director of product marketing for passenger cars and light trucks.
Tires must be inspected for age, as well as cuts, bulges and wear to the tread. Tires should be replaced when tread depth reaches 3/32 inch or when the age reaches six-years. Age can be determined by the DOT number that will be imprinted on the sidewall. The last four digits show the week and year of manufacture.
18. Transfer Case Fluid (4 wheel drive only)
The lubricant in a transfer case gets dirty, can absorb moisture and suffer diminished properties over time. Debris is produced by the gears, bushings, chain and moving components. As a general rule we recommend transfer case fluid replacement between 50,000 and 100,000 miles, more often when towing. Transfer cases, like transmissions often use a specialized lubricant. Service data should always be consulted before replacing transfer case fluid on any four-wheel drive vehicle.
19. Wheel Bearings
Many new vehicles use sealed wheel bearings that and cannot be serviced. On other vehicles bearings need to be removed, cleaned, inspected, packed with fresh grease and the seals need to be replaced. On some vehicles the front bearings are able to be packed and on others vehicles the rear may need to be done as well.
On vehicles with bearings that can be packed, the service is normally performed at each brake service or around 50,000 miles.