CHAPTER 5

BASIC VEHICLE CONTROL

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Introduction

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Driving a personal vehicle is quite different from driving a tractor-trailer. Starting the engine, backing up, and turning a tractor-trailer all demand new knowledge and abilities. Basic control- related concerns are covered in this chapter. Given that many of the abilities discussed in this chapter serve as the basis for subsequent lectures, you must have a solid knowledge of these topics.

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Starting, Warming up, and Shutting Down

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When starting and stopping the engine of a tractor-trailer, a certain process must be followed. The correct method for starting a four-cycle diesel engine will be covered in this section.

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Starting the engine — Observe these procedures to start this sort of engine:

• Set the parking brake on (if not already applied).

• Make sure the vehicle is in neutral and depress the clutch pedal to the bottom.

• Switch on the ignition using the key.

• Start the engine (push the button). Turn off the ignition switch or key for at least one minute before trying again if the engine does not start after 15 to 20 seconds.

• Release the clutch slowly.

• Verify all gauges and instruments. You should be aware of the location of the oil pressure gauge. The oil pressure should reach operating pressure in 3 to 5 seconds during warm weather. If it doesn't, you should turn off the vehicle sight away to prevent further harm.

 

Engine warm-up — typically, the engine is warmed up at a low rpm level (800-1,000 rpm). As a result, the oil may warm up, circulate, and develop pressure.
The cylinder walls get coated and the bearings are lubricated during warm-up. Air pressure rises as the temperature of the coolant rises.

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Usually, just a brief amount of idle time is needed or advised. For specifics unique to the vehicle you are driving, see the owner's handbook.

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Keep your RPMs modest and steer clear of high RPMs while accelerating in first gear when driving during warm-up. Quickly change into the next highest gear. Keep every acceleration gentle and smooth.

When the water hits 170°–195°F, the engine has finished warming up. You must move slowly at low rpm until this temperature range is attained since you will not generally reach this temperature by just sitting and idling.

 

Engine shutdown — Follow these procedures to turn off the engine:

1. Press the clutch while shifting into neutral.

2. Engage your parking brake.

3. Use the key or switch to stop the engine.

4. Set the engine's Stop control to Off if it has one.

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An appropriate warm-up is crucial, but so is an engine cool-down. Inadequate cooling down time might result in engine damage. The heat created during regular operation may be dissipated by letting the engine cool down. The sight cooling down time will depend on the kind of engine, the route taken, and the load being transported.

Excessive idling — Limit your idle time. Most newly produced engines do not need more than a few minutes of idling. This may result in fuel waste and pointless engine wear. Additionally, it harms the driver's fuel benefit!

 

Putting the Vehicle in Motion and Stopping

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When compared to operating the same chores in your vehicle, operating a tractor-trailer demands more specialized abilities and driving competence. This comprises:

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• Checking the trailer-trailer connection;

• Starting up the tractor-trailer; and
• The tractor-trailer must be stopped.

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Please take notice that manual transmission automobiles are the focus of this section. If you use an automatic gearbox, look up specifics in the owner's handbook.

Testing the tractor-trailer hook-up — Every time a trailer is linked to a tractor or dolly, the coupling has to be inspected.

 

For vehicles equipped with a hand valve-based independent trailer brake control:

1. Release the parking brake on the tractor. The red 8-sided button is seen here.

2. Push the gearshift into the lowest gear while depressing the clutch.

3. Apply the trailer brakes by activating the independent trailer brake control (pull down on the Johnny bar).

4. Let the clutch release to the friction point.

5. Gently drag the trailer brakes that are locked. As soon as you see that the engine is

   beginning to lag, stop.

6. Release the clutch.

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For automobiles devoid of a hand valve-operated independent trailer braking system:

1. Release the parking brake on the tractor.

2. Push the gearshift into the lowest forward gear while depressing the clutch

3. Pull the trailer air supply valve to adjust the trailer brakes.

4. With the clutch partially engaged, slowly drag the trailer brakes forward.

 

Putting a tractor-trailer in motion — To begin driving of a tractor-trailer:

1. Release the parking brakes on the tractor and trailer.

2. Set the gearbox to the lowest gear while completely depressing the clutch and activating

   the clutch brake.

3. Slightly raise the engine's revs. (In more recent trucks, this may not be required.)

4. Let the clutch release to the friction point. At this time, the clutch activates. The friction

   point has been achieved when the rpm begins to drop. Once completely engaged,

   release the clutch gently.

5. By depressing the throttle, the driver may gradually raise the engine rpm as the vehicle

   moves forward.

6. Take your foot off the clutch when it is fully engaged and wait to shift or stop.

7. Avoid clutch sliding too much. As smoothly as you can without stalling the engine, engage the clutch. Use very little more gasoline (pressing on the) until the clutch is fully engaged to prevent clutch slippage.

 

 

Stopping a tractor-trailer — To stop a tractor-trailer:

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Let go of the gas pedal.

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Press down on the brakes.

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As the vehicle starts to slow down, downshift to the proper gear.

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Release part of the brake pressure as the vehicle slows down. Depress the clutch while the engine is practically idle (the truck should be stopped within the next 50-75 feet).

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After stopping, keep the brakes down firmly enough to keep the vehicle still. Put the gearshift lever in neutral, engage the parking brakes, and let go of the clutch if you are parking the truck.

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Straight Line Backing

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Despite being a fundamental tractor-trailer action, the backing is one of the trickiest to learn. The simplest of all backing actions, straight-line backing, is described in the material that follows as an introduction and basic overview.
Performing a straight-line backing movement involves:

• Position the vehicle properly — Position the vehicle by moving ahead until the front (steering) wheels are straight and the tractor and trailer are directly in front of one another.

• Clear the area— Verify that there are no other vehicles, pedestrians, or obstructions in the space behind your vehicle. Turn on the four-way flashers and honk the horn of your vehicle.

• Watch speed — Place the vehicle in reverse. Back as gently as you can while maintaining an idle pace, but avoid riding the clutch or brakes.

• Check behind — Always look behind you while backing up. Check all mirrors often and make sure all doors are shut. Stop if you have any doubts about what could be lurking behind your vehicle.

• Steering — Keep a straight course and avoid oversteering.

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As soon as drifting begins, attempt to stop it by moving the steering wheel in the direction of the drift. Avoid oversteering. If the drift is immediately recognized, only slight movement is necessary.

 

To maintain the trailer straight, steer using the push-pull technique. When the trailer seems larger in your rearview mirror (an indication that it is drifting), spin the top of the wheel in the direction of the larger side. Set the wheel back in place after the drifting has stopped, then adjust the tractor so that it is in front of the trailer.

 

Pull up and start again — Pull up and restart if your vehicle is too far out of place. Starting anew rather than repositioning the vehicle while the backing is safer and simpler.

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Turning

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When turning, there are four fundamental guidelines to follow: Know the vehicle;
Plan in advance;
Allow for off-tracking;

Watch your mirrors.

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Off-tracking — Any vehicle with more than one set of wheels may sometimes go off-tracking. The phrase simply implies that when a vehicle is traveling through a bend or curve, the rear wheels do not follow the same track as the front wheels. They choose a shorter route.

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In a tractor-trailer unit, off-tracking is influenced by three factors:

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• The distance between the kingpin and the back wheels of the trailer (the larger the distance, the more off-tracking happens);

• The amount of sideways drag generated by the back tires (the

  more sideways drag, the more off-tracking);

• Vehicle speed (reduced off-tracking at motorway speeds).

   

 

Sight turns — Safe sight turns to need sound judgment, effective speed management, and precise steering.

The speed of your vehicle should be adjusted as you approach an intersection. The vehicle should be traveling more slowly as the curve becomes sharper. This lets you use every square inch of the room.

Before the turn, shift into the appropriate gear, and stay in that gear to make the turn. This enables you to make the turn with both hands on the wheel.

To avoid striking the curb, a tractor-trailer must approach the junction from a greater distance than a smaller vehicle. One general guideline is to start the turn after getting roughly half of the rig through the bend. Once the vehicle has arrived at that spot, complete the turn by turning the steering wheel to the sight. To make the turn more fluid, accelerate a little.

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Check the sight and left mirrors for the location of the trailer wheels before, during, and after the turn.

Position your trailer so that no vehicles may pass between it and the curb as you approach a bend for a sight turn.

Turn the steering wheel back to straighten the wheels as soon as the turn is over.

Some of the most typical mistakes committed while making a sight turn include the following:

. Failing to correctly assess the corner; 2. moving too quickly toward the junction;

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Left turns — When making a left turn, slow down your vehicle as you approach the junction.

To allow the tractor plenty of space, turn from as far to the sight as you can while doing this motion. Off-tracking may result in the left side of the vehicle colliding with another vehicle if you turn too quickly or tightly.

Before, though, and after the turn, keep an eye on your mirrors. Immediately after making the turn, spin the steering wheel back to the sight.

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The most frequent mistakes made while making a left turn are identical to those made when making a sight turn, except that the mistakes are committed by the other side.

Use the outer (sightmost) lane while making a left turn on a road with two lanes.

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Curves — Positioning is important. Keep the vehicle near the middle of the road without going over the center line as you approach a sight-traveling curve (not a corner). If you do not stay in the middle, your vehicle can veer off the road, into the shoulder, or collide with anything on the sight side.

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Keep the front of the vehicle as near to the outside border of the road as you can while approaching a left-turning curve. By doing this, you may prevent your trailer from crossing the center line while turning. Recognize impending curves by looking ahead. Remember that you may sometimes need to stop and let oncoming traffic pass before continuing.

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Summary

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As you now know, a tractor-trailer operates differently from your vehicle on a fundamental level. Starting and stopping a tractor-trailer, as well as backing and negotiating corners, all require following precise, predetermined protocols. Keep in mind that actions like backing up and turning need expertise, patience, and planning. 


• .  Forgetting to shift into reverse before making a turn; .

• .  Accelerating for the bend; .

• .  Shifting gears as you turn; .

• .  Excessively widening the distance between the trailer and the curb; .

• .  Forgetting to account for detours;

• .  Ignoring looking in the sight mirror before, during, and after the turn.