Car Semiannual Adjustments


Many car owners check and replace fluids, but draw the line at making adjustments to their cars. Others see adjustments as another area where they can save some money and, just maybe, increase their pride of ownership. This article describes the steps you can take every six months or 6,000 miles to keep your car well adjusted. As with other tasks in this website, you can do them yourself, or you can hire others to do them for you. In either case, this article will help you understand what needs to be done, why, and how.

Semiannual Specials

There are thousands of parts in your car. Some just sit there like car potatoes, enjoying the ride. Others are hard workers with a mission. Depending on how much they are called upon to work (and how well they were made), these hard-working parts will need to be adjusted every once in a while. On average, once in a while means about every six months or 6,000 miles of driving. Your mileage may vary. Your car’s carburetor (if not fuel-injected) mixes hundreds of gallons of fuel with the appropriate amount of air before it needs to be adjusted, for example. Your car’s tires will roll many thousands of miles before their position on the car needs to be rotated to even out the wear. Other adjustments your car will need include throttle linkage and brakes.

Car Carburetor

Okay, let’s weigh this against the cost of a new oil filter: less than five bucks (less than three bucks for many cars). So here’s the new rule I ask you to follow: Always change the oil filter when you change the oil. On behalf of your car, thanks!In addition to getting an oil filter for the oil change, you need oil! How much oil? Look in the owner’s manual. It may say something like oil capacity: or crankcase capacity: 3.5 L (3.7 qt.) including filter. Oil containers usually have marks on the side to indicate milliliters (ml) or ounces (oz).

To replace the oil and filter on your car, follow these steps:

  1. As usual, make sure your car is parked in a level spot. Start your car and let the engine run for about 15 minutes to warm up the oil. Warm oil drains more thoroughly and brings with it more built-up sludge. Use this time to gather the tools you’ll need: a wrench (to remove the oil pan plug), an oil-draining pan, and an oil filter wrench. Rubber gloves will keep warm oil off your skin. Shut off the engine when you are ready to start. Wait about five minutes for the warm oil to drain to the lowest spot in the engine, the oil pan.
  2. Place the drain pan under the oil pan plug. The plug has a bolthead and is located at the lowest point underneath the engine. If necessary, jack up the car and install safety stands. Using a wrench, tum the plug counterclockwise to loosen it. Set the plug and washer aside for later. Alternatively, you can use a hand-operated oil siphon to draw oil from the oil pan through the dipstick tube without having to crawl under the car.
  3. After all oil is drained into the pan, reinstall the old plug and a new washer on the oil pan. Tighten the plug with a wrench. Don’t forget this step or your car’s engine could be ruined by operating as oil drips out the bottom. It would slowly bleed to death-not a pretty sight.
  4. Move the pan to below the oil filter. On some engines, the oil filter can be reached from under the hood. Others require that you remove it from underneath the car. If necessary, jack up the car and install safety stands. Be careful when working around the underside of your car because the exhaust pipe and other components are hot.
  5. Using an oil filter wrench, twist the filter counterclockwise two or three turns. Oil should begin dripping from the filter to the pan. Use your hand to rotate the oil filter until it comes off the shaft. Then tilt the filter so that oil in it can drain into the drip pan.
  6. Make sure the new oil filter is the same size as the old one. Open a can of new oil, get some oil on the end of a rag or your finger, and spread it around the circular rubber seal on the end of the new oil filter. Place the new oil filter on the screwon filter shaft and tum it clockwise. Tighten the new filter by hand only, about two-thirds of a tum after the gasket makes contact with the filter holder. Don’t tighten the filter with the oil wrench.
  7. Replace the oil, find the oil filler location and use a funnel to pour in the appropriate amount of oil, and then recheck the oil to make sure it’s between the ADD and FULL marks.
  8. Replace the oil filler cap securely. Wipe off all tools with a clean rag and put them away for later use. Make sure you take the used oil to a recycling center or an auto parts store to have it properly disposed of. If you DON’T recycle oil properly, a large fellow who grunts with an accent will recycle you!

Check your oil level after your next short drive. Make sure the oil level is within range: above ADD and below FULL on the dipstick. Add oil as needed. Also look under the car to see whether there are any new oil drips, indicating that the oil plug or oil filter is not tight.

Adjust Car Carburetor

How Much Gas Do You Want? Adjust Throttle Linkage

The throttle linkage is simply the part of your car that uses your foot pressure on the accelerator pedal to control the amount of fuel going to the carburetor or fuel injectors. It’s a mechanical system of linkage, cable, and connections. Some cars seem to need throttle adjustment many times a year, but others require it only every few years. The best way to adjust the throttle linkage on your car is to refer to the car’s service manual. Every car has a slightly different linkage. Even so, they all work on the same principles. If you don’t have a service manual or you just want an overview of how the throttle works, keep reading. This job requires an assortment of wrenches and maybe a screwdriver or two (no, still not the liquid kind). You might also need some lubricant, depending on the linkage and its condition.

To adjust the throttle linkage on your car, follow these steps:

  1. Open the hood of your car and look for the throttle linkage system. It consists of one or more rods, cables, springs, and metal plates between the car’s firewall and carburetor. You may have to remove the air filter from the top of the carburetor to see all of it.
  2. Starting at the firewall, wiggle the parts to make sure they are fastened securely to their mountings and to each other. Tighten any loose mounting bolts. Don’t move the throttle linkage forward and back too often because it will put fuel in the carburetor, “flooding” it and making starting the car more difficult.
  3. Carefully spray the linkage joints with WD-40 or similar cleaning lubricant so they move freely. Wipe away excess lubricant.
  4. If possible, disconnect the end of the linkage from the side of the carburetor. Some connections snap off, others might require removing a pin or clip. Then move the throttle linkage forward and back a few times to make sure it works smoothly. Tighten and lubricate as needed. Reconnect the linkage when done.

Car Semiannual

Adjust the Carburetor

If your car has a fuel-injection system instead of a carburetor (refer to your owner’s manual), there’s not much you can or have to adjust. Fuel is regulated by an electronic signal from your car’s computer. The carburetor is an important part of many cars over a decade old. It mixes the right amount of fuel and air to make a combustible vapor that your engine’s spark plugs can ignite. The adjustments you can make are the ratio of fuel to air (rich or lean) and the amount of fuel fed to make the engine operate when the car isn’t moving (at idle). Most newer carburetors are sealed at the factory and don’t allow owner adjustments. So you can spend the time required to adjust the carburetor doing something else.

But if you have an older car and need to adjust the carburetor, here’s how to do it:

  1. Attach a tachometer to your car’s engine following the manufacturer’s directions-unless your car already has a tach in the instrument cluster. Tachs measure the engine’s operating speed in revolutions per minute (rpms).
  2. Start the engine and let it run for about 15 minutes to warm it up. Look it over.You’re looking for screwheads that can be turned to adjust the idle speed and the idle mixture. Hints: The idle speed screw is at the end of the throttle linkage and at the side of the carburetor; the idle mixture screw (or screws) is on the carburetor itself.
  3. To adjust the idle speed, you use the tachometer to set the engine’s speed at idle. Your car’s owner’s manual tells you what that speed should be, or there may be a sticker on the inside of your car’s hood that indicates the idle speed. For many cars, idle speed is 500 to 750 rpm. Using a screwdriver, turn the idle speed adjustment screw clockwise to increase rpms or counterclockwise to decrease rpms. If your carburetor has an idle solenoid adjustment, you need to make a second adjustment for a high idling speed. There are many carburetor designs out there. Follow instructions in your car’s service manual for this adjustment.
  4. To adjust the idle mixture, make sure the tachometer is connected to the engine to tell you its operating speed. Find the idle mixture adjustment screws on the carburetor (underneath the air cleaner). A single-barrel carburetor (on smaller or older cars) has one idle mixture screw, whereas a two- or four-barrel carburetor has two screws. Turn the screw(s) in, or clockwise, until the engine is at its lowest speed. Then turn them out, or counterclockwise, until further turning doesn’t increase speed. That’s the best mixture for the idling speed. Do this a couple of times to get the best mixture, especially if your car has two idle mixture adjustments.

Car Throttle Linkage

Adjusting Brakes

When ya gotta stop, ya gotta stop-and you won’t if your brakes aren’t in good shape and properly adjusted. The brakes on your car should be checked and, if necessary, adjusted about every six months, depending on mileage. City drivers probably use brakes (and horns) more frequently than rural drivers. However, cars driven on dusty rural roads can collect dirt on brake components.

Foot pressure on the brake pedal is transferred hydraulically to the four brakes, one at each wheel. Two types of brake systems are in use today. The wheels may have eitherdrum or disc brakes, or both-drums in the rear and discs on the front. Drum brakes slow down the car by pressing two half-circle brake shoes against the inside of a round brake drum. Disc brakes perform the same function by squeezing brake pads against both sides of a round brake disc.

Adjusting brakes simply means making sure the brake shoes or brake pads are close to the friction surface but not so close as to drag and wear out. Smart folks that they are, brake manufacturers include provisions for adjustments of their systems. In fact, many drum and all disc brake systems are self-adjusting and really don’t need your help to keep themselves well-adjusted.

Besides basic tools, you may need a brake spoon, a tool that looks like a bent flat screwdriver. In fact, if you don’t have a brake spoon, use a screwdriver for the adjustment.

To adjust drum brakes on your car, follow these steps:

  1. Safely jack up the car and place stands under it. You will be working from the back side of the wheels, so give yourself enough room to work.
  2. Find the brake adjustment access hole on the back side of the wheel. Many are near the bottom edge of the hub and covered with a rubber plug. Uncover the hole using a screwdriver to pry off the plug. Inside is a star wheel adjusting nut with lobes or bumps on it. Moving the lobes up or down rotates the star wheel and moves the two brake shoes into or out from the drum.
  3. Insert a straight screwdriver or a brake spoon into the adjustment hole until it contacts the star wheel adjusting nut. Grab the tire and spin it. At the same time, rotate the star wheel up by moving your end of the screwdriver or spoon down until the brakes stop the wheel from moving. The brake shoes are now in contact with the inside of the brake drum.
  4. To back the brake shoes off the brake drum, rotate the star wheel down by moving your end of the screwdriver or spoon up. Remove, reinsert, and repeat the movement three more times to back the brake shoes off the drums. Spin the wheel by hand and listen for the drag of brake shoes on the drum. As needed, repeat the process of moving the star wheel, one lobe at a time, until the brake shoes don’t drag against the drum.
  5. Reinstall the brake adjustment access hole cover.
  6. Repeat the process on the other drum brakes.

As you adjust your car’s brakes, or even if they are self-adjusting, spend a few moments visually inspecting the system. The brake system uses hydraulic pressure that presses brake parts together to slow the wheels. Brakes use hydraulic fluid inside heavy-duty hoses, so look for these hoses running to the back side of your car’s wheels. Inspect the hoses for wet spots where fluid may be leaking. Also look at the back side of the wheel where the brake hose attaches.

Adjust Tire Rotation

Car tires are, literally, where the rubber meets the road. As they roll their way to your destination, they also wear out. Old bias tires wore out in 10,000 to 20,000 miles. New radials last four times as long-unless they don’t wear evenly. It’s easy to reduce uneven tire wear by making sure tires are inflated properly and rotated or moved to different positions on the car to equalize wear (forthcoming). Not all car and tire manufacturers recommend rotation. Some suggest that tires should be replaced when they are worn, without first trying to rotate them. Tests have shown that rotation doesn’t prolong tire life; it only makes wear more even among the four tires. They suggest that front tires frequently wear faster than rear tires (which is why they are rotated) so they should be replaced as a set. The rear tires also should be replaced as a set when worn. Check your car’s owner’s manual for the tire rotation pattern, if any, suggested for your car. The only tools you’ll need for the job are those that came with your car: a jack and a lug wrench, also known as a tire iron.

Car Brakes Adjust

To rotate the tires on your car, follow these steps:

  1. Safely jack up and place stands under all four wheels of your car. If you cannot lift all four wheels, jack up and place stands under one side of your car or the other.
  2. Remove wheels as needed, reinstalling them on the car for the most even and efficient wear, as recommended by the car’s owner’s manual.

For front-wheel-drive cars and front-engine, rear-wheel-drive cars with radial tires, move the front left tire to the left rear and vice versa. Then move the front right tire to the right rear and vice versa. For front-engine, rear-wheel-drive cars with bias-ply tires, move the front left tire to the rear right, the rear right to the front right, the front right to the rear left, and the rear left to the front left wheel. Got that? If your car’s spare tire is a standard tire (rather than one of those weird spare-only tires that look like a large chocolate cruller), you might want to rotate it among the others. If so, rotate as recommended by the manufacturer.