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ASE H5 Suspension & Steering (Transit Bus) study materials
ASE H5 Suspension & Steering (Transit Bus) study resources

ASE H5 Suspension & Steering (Transit Bus) practice questions

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Question 1Steering Systems Diagnosis and Repair

A transit bus with hydraulic power steering has a whine that is loudest when the wheel is held against the steering stop and quiets when the wheel is centered. Which condition best fits this symptom?

  1. A loose pitman arm nut
  2. A restricted or slipping power steering pump drive Correct answer.
  3. Worn kingpin bushings
  4. Air trapped in the return line

Explanation

Holding the wheel against a stop loads the pump to maximum relief pressure, so a slipping belt or worn pump drive becomes loudest at that moment. Noise that tracks with pump load points to the pump or its drive rather than to steering linkage. Linkage wear does not produce a load-dependent whine.

Question 2Steering Systems Diagnosis and Repair

What is the primary purpose of the relief valve in a hydraulic power steering gear?

  1. To limit maximum system pressure Correct answer.
  2. To regulate fluid temperature
  3. To center the steering wheel
  4. To bleed air from the system

Explanation

The relief valve opens when system pressure reaches its set limit and bypasses fluid so that pressure cannot rise high enough to damage the pump, hoses, or gear. It does not perform bleeding, cooling, or centering functions. Those tasks belong to other components or procedures.

Question 3Steering Systems Diagnosis and Repair

A bus steering wheel has excessive free play before the front wheels begin to move. Technician A says the play may be in the steering shaft universal joints. Technician B says the play may be in the tie rod ends. Who is correct?

  1. Technician A only
  2. Both technicians Correct answer.
  3. Neither technician
  4. Technician B only

Explanation

Free play at the rim can come from any component between the wheel and the road wheels, including shaft joints, the steering gear, the pitman arm, drag link, tie rods, and the steering knuckles. Both technicians identify valid possible sources. Diagnosis requires isolating each joint while an assistant rocks the wheel.

Question 4Steering Systems Diagnosis and Repair

Which fluid is normally specified for a transit bus hydraulic power steering system?

  1. 50/50 ethylene glycol coolant
  2. DOT 4 brake fluid
  3. Automatic transmission fluid or the manufacturer-specified power steering fluid Correct answer.
  4. Engine oil of the viscosity shown on the fill cap

Explanation

Power steering systems use ATF or a dedicated power steering fluid as specified by the manufacturer, because the fluid must lubricate the pump, resist foaming, and maintain the correct seal compatibility. Engine oil, brake fluid, and coolant do not meet those requirements. Always confirm the specification on the reservoir cap or in the service information.

Question 5Steering Systems Diagnosis and Repair

A bus has a steering wheel that is hard to turn at low engine idle but turns normally at higher engine speed. Which is the most likely cause?

  1. A seized tie rod end
  2. A worn steering column bearing
  3. A low idle speed or weak pump output at low rpm Correct answer.
  4. An incorrectly indexed steering wheel

Explanation

Hydraulic assist depends on pump flow, and flow rises with engine speed. Effort that is high at idle but normal at higher rpm indicates insufficient pump output at low speed, which may come from low idle, a worn pump, a slipping drive, or a restricted inlet. Mechanical binding in the linkage would make steering hard at all speeds.

Question 6Steering Systems Diagnosis and Repair

In a conventional integral power steering gear, what does the torsion bar do?

  1. It senses driver input torque and moves the control valve Correct answer.
  2. It absorbs road shock before it reaches the wheel
  3. It limits maximum steering angle
  4. It returns the wheels to straight ahead after a turn

Explanation

The torsion bar twists slightly in proportion to the torque the driver applies, and that twist moves the rotary control valve to direct pressure to the correct side of the piston. It is an input-sensing element, not a centering spring or a travel stop.

Question 7Steering Systems Diagnosis and Repair

A transit bus steering system uses a hydraulic retarder feature on the steering gear. What is the purpose of this feature?

  1. To lock the steering when the engine is off
  2. To increase assist during parking maneuvers
  3. To slow the steering rate at high vehicle speed Correct answer.
  4. To reduce fluid temperature at idle

Explanation

Some heavy-vehicle steering gears reduce assist or flow at higher road speeds so that steering response is less sensitive and the driver does not oversteer. Assist is normally highest at low speed for parking. The feature does not lock the steering or serve as a cooling device.

Question 8Steering Systems Diagnosis and Repair

Which component transmits steering input from the steering gear output shaft to the drag link on a typical transit bus?

  1. Steering knuckle
  2. Center link
  3. Pitman arm Correct answer.
  4. Idler arm

Explanation

The pitman arm is splined to the steering gear output shaft and converts the gear's rotary output into motion of the drag link. The idler arm supports the opposite end of the linkage, and the center link ties the linkage together. The knuckle is the wheel-carrier at the axle end.

Question 9Steering Systems Diagnosis and Repair

A bus is reported to wander and require constant correction at highway speed. Technician A says excessive caster may be the cause. Technician B says a worn steering gear or excessive free play may be the cause. Who is correct?

  1. Technician B only Correct answer.
  2. Neither technician
  3. Technician A only
  4. Both technicians

Explanation

Insufficient positive caster reduces directional stability and causes wander, while excessive caster increases steering effort and can contribute to shimmy. Excess free play in the gear or linkage also causes wander because the driver must take up lost motion before the wheels respond. Therefore only Technician B's statement is accurate as written.

Question 10Steering Systems Diagnosis and Repair

During a pressure test of a power steering pump, the pressure is within specification at idle but drops sharply when the steering wheel is turned to full lock. What does this indicate?

  1. The pump is worn and cannot maintain flow under load Correct answer.
  2. The system has excessive fluid
  3. The steering gear is over-adjusted
  4. The relief valve is stuck closed

Explanation

A pump that meets pressure at idle but cannot hold pressure under load has internal leakage or wear that shows up only when flow demand is high. A stuck-closed relief valve would produce excessive pressure, not a drop. Fluid level and gear adjustment do not explain a load-dependent pressure loss.

Question 11Steering Systems Diagnosis and Repair

A transit bus has a steering wheel that shudders or vibrates at idle when the wheels are turned slightly. Which is the most likely cause?

  1. Incorrect toe setting
  2. A worn idler arm bushing
  3. Air in the hydraulic system Correct answer.
  4. A bent wheel

Explanation

Air entrained in the hydraulic fluid compresses under pressure and produces pulsation or shudder that is felt through the wheel, especially when the pump is loaded. A worn idler bushing or incorrect toe causes handling complaints but not hydraulic shudder. A bent wheel causes a vibration that varies with road speed.

Question 12Steering Systems Diagnosis and Repair

When checking steering linkage for wear, why should the wheels be on the ground and the steering wheel held steady while an assistant rocks it?

  1. To load the joints so that lost motion becomes visible Correct answer.
  2. To keep the power steering pump from running
  3. To prevent the airbag from deploying
  4. To align the steering wheel to center

Explanation

Loading the linkage by leaving the tires on the ground and rocking the wheel takes up clearance in one direction, so any remaining movement at a joint is visible as lost motion. The procedure is about loading the joints, not about disabling the pump or the airbag. Centering the wheel is a separate adjustment.

Question 13Steering Systems Diagnosis and Repair

A transit bus with a hydraulically assisted steering gear has fluid leaking from the sector shaft seal. Which condition most directly causes this leak?

  1. An overcharged air conditioning system
  2. A worn sector shaft bearing or seal Correct answer.
  3. A clogged reservoir filter
  4. A loose steering wheel nut

Explanation

The sector shaft seal retains fluid where the pitman shaft exits the gear. A worn seal or a shaft bearing that allows the shaft to move and damage the seal will produce a leak at that location. A clogged filter causes aeration or noise, and the other options are unrelated to the gear's hydraulic sealing.

Question 14Steering Systems Diagnosis and Repair

What is the correct way to center the steering wheel on a bus with a parallelogram linkage after the toe has been set?

  1. Adjust the drag link so the gear is centered and the wheel is straight Correct answer.
  2. Bend the pitman arm to compensate
  3. Adjust both tie rod ends equally in opposite directions
  4. Remove and re-index the steering wheel on the shaft

Explanation

The steering gear must be at its internal high point when the wheels are straight ahead, and the drag link adjustment brings the wheel to center without disturbing the toe setting. Re-indexing the wheel on the shaft can hide a mis-centered gear and reduce the return-to-center feel. Tie rod adjustments change toe.

Question 15Steering Systems Diagnosis and Repair

A bus has a steering column with a tilt and telescope feature. The driver reports the wheel moves up and down over bumps. Which is the most likely cause?

  1. Low power steering fluid
  2. A worn drag link
  3. Incorrect caster
  4. Worn tilt mechanism lock or column bearings Correct answer.

Explanation

Movement of the wheel relative to the column over bumps points to looseness in the tilt lock, the column bearings, or the column mounting. Hydraulic fluid level, drag link wear, and caster affect steering effort and handling but not the physical position of the wheel in the column.

Question 16Steering Systems Diagnosis and Repair

What does the term "steering axis inclination" describe, and how does it affect steering?

  1. The tilt of the kingpin or ball joint axis from vertical, which aids return to center Correct answer.
  2. The angle of the wheel plane relative to the vehicle centerline
  3. The amount the wheel leans inward at the top
  4. The angle of the steering column relative to the floor

Explanation

Steering axis inclination is the inward tilt of the steering axis from vertical as viewed from the front. Combined with caster, it creates a self-centering effect and affects scrub radius. It is not the column angle, the toe angle, or camber.

Question 17Steering Systems Diagnosis and Repair

A bus has a power steering system that is overfilled and the fluid foams after a long run. Which is the most likely explanation?

  1. The fluid is aerated because the return line is drawing air or the level is incorrect Correct answer.
  2. The pump is producing too much pressure
  3. The relief valve is stuck open
  4. The steering gear is worn out

Explanation

Foaming indicates air entrained in the fluid, which can come from an incorrect fluid level, a leaking suction line, or a restricted return. Overfilling can cause the fluid to be churned by the pump and to overflow, and any air leak on the suction side will aerate the fluid. A stuck relief valve or worn gear does not produce foam.

Question 18Steering Systems Diagnosis and Repair

Which procedure correctly bleeds air from a power steering system after repairs?

  1. Run the engine at high speed and hold the wheel at full lock for one minute
  2. Drain the system and refill without turning the wheel
  3. Loosen the pressure line and crank the engine until fluid sprays out
  4. With the engine off, turn the wheel lock to lock several times while checking and topping the fluid, then run and recheck Correct answer.

Explanation

Turning the steering from lock to lock with the engine off purges air through the system without the pump churning the fluid into foam. The level is then rechecked with the engine running and the wheel cycled again. Holding at full lock or loosening a pressure line under pressure can damage components or cause injury.

Question 19Steering Systems Diagnosis and Repair

A transit bus has a steering gear with a known internal leakage past the piston seal. What symptom would you expect?

  1. Increased assist and very light steering
  2. Excessive fluid pressure at the relief valve
  3. A steering wheel that will not return to center
  4. Reduced assist and hard steering, especially at low engine speed Correct answer.

Explanation

Leakage past the piston seal lets pressure bypass from one side of the piston to the other, so less force is available to assist steering. The effect is most noticeable when pump output is lowest, such as at idle. It does not increase assist or raise relief pressure.

Question 20Steering Systems Diagnosis and Repair

A bus with a hydraulic power steering system has a steering wheel that turns easily to the left but is hard to turn to the right. Which is the most likely cause?

  1. A restricted return line
  2. Low tire pressure on the right front
  3. A worn left tie rod end
  4. A sticking flow control valve in the gear Correct answer.

Explanation

Asymmetric effort indicates that the control valve or its passages are not directing pressure equally in both directions, such as a sticking valve spool or a blocked passage on one side. A restricted return line affects both directions, and tire or linkage issues do not create a left-right hydraulic difference.

Question 21Steering Systems Diagnosis and Repair

During a steering system pressure and flow test, the flow gauge reads within specification at idle but drops below specification at 1,500 rpm. Which conclusion is best supported?

  1. The gauge is connected backwards
  2. The relief valve is opening too early
  3. The system has a restriction in the return line
  4. The pump is worn and its flow falls off as speed rises Correct answer.

Explanation

A pump should maintain or increase flow as speed rises up to the flow control limit. Flow that falls off with increasing speed indicates internal wear or a slipping drive that cannot keep up. A return restriction or an early-opening relief valve would show as high pressure or bypass flow, not a speed-related flow loss.

Question 22Steering Systems Diagnosis and Repair

A transit bus equipped with a variable-assist steering system has heavy steering at low speed and normal effort at high speed. Which component is most suspect?

  1. The variable-assist control solenoid or its signal circuit Correct answer.
  2. The steering gear input shaft seal
  3. The drag link
  4. The front wheel bearings

Explanation

Variable-assist systems increase assist at low speed and reduce it at high speed. Heavy effort at low speed with normal effort at high speed means the system is not increasing assist when it should, which points to the control solenoid, its wiring, or the controller. Seals, drag links, and wheel bearings do not produce a speed-dependent assist change.

Question 23Steering Systems Diagnosis and Repair

A bus has a steering wheel that is hard to turn and the pump is noisy, with the fluid level correct. A pressure test shows pressure above specification at idle with the wheel centered. Which is the most likely cause?

  1. A stuck-closed flow control or relief valve Correct answer.
  2. A loose belt
  3. A worn pump
  4. Air in the system

Explanation

Pressure above specification with the wheel centered means the pump is not bypassing flow as it should, which points to a stuck-closed flow control or relief valve. A worn pump would produce low pressure, a loose belt would reduce output and cause slip noise, and air causes foaming and pulsation rather than high pressure.

Question 24Steering Systems Diagnosis and Repair

A transit bus has a steering system that pulls to the right on a level road. Which check is the most appropriate first step?

  1. Increase caster on the left side
  2. Adjust the toe to compensate
  3. Replace the steering gear
  4. Compare tire pressures and check for a dragging brake or worn suspension component Correct answer.

Explanation

A pull can come from unequal tire pressure, a dragging brake, a worn control arm or bushing, or an alignment problem. Confirming tire pressures and checking for a dragging brake or worn suspension is a low-cost first step that can identify the cause before parts are replaced. Replacing the gear or altering alignment to mask the pull is inappropriate.

Question 25Steering Systems Diagnosis and Repair

When replacing a power steering hose on a transit bus, which practice is most important for preventing later failure?

  1. Reusing the original O-rings
  2. Using any hose that fits the fittings
  3. Using a hose rated for the system's pressure and compatible with the specified fluid Correct answer.
  4. Routing the hose so it touches the exhaust manifold

Explanation

Power steering hoses must be rated for system pressure and compatible with the specified fluid, or they can burst or degrade from the inside. Reusing old seals risks leaks, and routing a hose near a heat source causes rapid deterioration. Fit alone does not ensure pressure or fluid compatibility.

Question 26Steering Systems Diagnosis and Repair

On a transit bus with a recirculating-ball integral power steering gear, which component converts rotation of the steering wheel into linear movement of the pitman arm?

  1. The torsion bar and spool valve
  2. The rack and pinion gear set
  3. The ball nut and sector shaft assembly Correct answer.
  4. The drag link and tie rod assembly

Explanation

In a recirculating-ball gear, the ball nut travels on the worm shaft and its rack teeth rotate the sector shaft, which moves the pitman arm. The other listed parts either provide valve control, transfer motion outside the gear, or are not used in this gear type.

Question 27Steering Systems Diagnosis and Repair

A transit bus steering system uses a hydraulic power steering pump driven by a belt. The technician finds the belt glazed and slipping under load. Which symptom is most likely to result?

  1. A steering wheel that returns too quickly after a turn
  2. Premature wear of the tie rod ends
  3. Increased steering effort during parking maneuvers Correct answer.
  4. Excessive caster angle on the front axle

Explanation

A slipping belt reduces pump speed and output flow, so assist drops when demand is highest, such as at low speed. Steering geometry and linkage wear are not caused by belt condition.

Question 28Steering Systems Diagnosis and Repair

When inspecting a transit bus steering column for a complaint of excessive steering wheel free play, which check is performed first?

  1. Adjust the front toe setting
  2. Measure pump relief pressure at the gear
  3. Check the steering shaft universal joints and column bearings for looseness Correct answer.
  4. Replace the steering gear sector shaft seal

Explanation

Free play is traced from the wheel down through the column, intermediate shaft, and gear before any hydraulic or alignment work. Worn universal joints or column bearings commonly account for lost motion at the wheel.

Question 29Steering Systems Diagnosis and Repair

What is the primary function of the power steering fluid cooler on a transit bus?

  1. To store reserve fluid for the system
  2. To increase pump output pressure at low engine speed
  3. To remove heat generated by continuous steering and pump work Correct answer.
  4. To filter metal particles from the fluid

Explanation

The cooler dissipates heat produced by the pump and gear during repeated steering, which is common in transit service. It does not raise pressure, filter, or act as a reservoir.

Question 30Steering Systems Diagnosis and Repair

A transit bus has a steering gear with a worn pitman shaft bearing. Which condition would the technician most likely observe during a dry park check with the engine off?

  1. Vertical movement of the drag link at the knuckle
  2. Free rotation of the tie rod adjuster sleeve
  3. Side-to-side movement of the pitman arm relative to the gear housing Correct answer.
  4. Axial movement of the steering wheel along the column

Explanation

A worn pitman shaft bearing allows the sector shaft to move laterally in its bore, showing up as side play at the pitman arm. The other conditions involve different components or normal adjustment features.

Question 31Steering Systems Diagnosis and Repair

During a power steering system flow test on a transit bus, the flow gauge reads within specification at idle but drops well below specification as the steering wheel is held against the stop. Which condition best explains this result?

  1. An overfilled reservoir
  2. A restricted return hose
  3. A worn pump rotor or vanes Correct answer.
  4. A loose pressure hose fitting

Explanation

Flow that falls off sharply under load indicates the pump cannot maintain volume, which points to internal wear such as a worn rotor, vanes, or cam ring. Restrictions and leaks would show up differently in pressure and flow readings.

Question 32Steering Systems Diagnosis and Repair

A transit bus has a steering wheel that is hard to turn in both directions, and the pump makes a whining noise. Fluid level is correct and the belt is tight. A pressure test shows pressure below specification at all times. Which item should be checked first?

  1. The steering gear spool valve centering
  2. The pump pressure relief valve and internal pump condition Correct answer.
  3. The steering column lock cylinder
  4. The front wheel alignment

Explanation

Low pressure in both directions with a noisy pump points to the pump itself, including the relief valve or internal wear. Directional complaints or alignment problems would not produce a system-wide low pressure reading.

Question 33Steering Systems Diagnosis and Repair

A technician is diagnosing a transit bus that steers hard only when the engine is at idle and the bus is stationary. Which test is most useful to isolate the cause?

  1. Check the front tire tread depth
  2. Inspect the front wheel bearings for end play
  3. Measure the steering wheel diameter
  4. Measure pump flow and pressure at idle with the steering held lightly off center Correct answer.

Explanation

Measuring flow and pressure at idle under a light steering load shows whether the pump delivers adequate assist at low engine speed. Tire and bearing checks relate to other complaints and do not measure hydraulic performance.

Question 34Steering Systems Diagnosis and Repair

A transit bus has a power steering system that loses assist intermittently and the fluid in the reservoir looks milky. Which condition is the most likely cause?

  1. Air entering the system on the suction side Correct answer.
  2. A misadjusted toe setting
  3. A worn sector shaft seal
  4. A sticking steering column universal joint

Explanation

Milky fluid indicates aeration, and intermittent assist loss is typical when air is drawn into the pump through a suction-side leak. Seal wear, toe, and column joints do not aerate the fluid.

Question 35Steering Systems Diagnosis and Repair

On a transit bus with a hydraulic power steering system, the driver reports the steering wheel kicks back sharply when driving over uneven pavement. Which component should be inspected first?

  1. The pump drive belt tensioner
  2. The reservoir cap vent
  3. The power steering fluid filter
  4. The steering damper or stabilizer, if equipped Correct answer.

Explanation

A steering damper absorbs road inputs that would otherwise reach the wheel, so a worn or leaking damper commonly causes kickback. The other items affect fluid condition or delivery but not road shock transmission.

Question 36Steering Systems Diagnosis and Repair

A transit bus steering gear is being replaced. Which step is required before disconnecting the hydraulic lines to reduce fluid loss and contamination?

  1. Run the engine until the fluid is hot
  2. Loosen the pitman arm nut
  3. Clean the fittings and cap the lines and ports Correct answer.
  4. Drain the front air tanks

Explanation

Cleaning around fittings and capping open lines and ports prevents dirt entry and limits fluid loss during gear replacement. Heating the fluid, loosening the pitman nut, and draining air tanks are unrelated to hydraulic line service.

Question 37Steering Systems Diagnosis and Repair

A transit bus with a hydraulic power steering system has a steering wheel that is off center after a steering gear replacement, though the front wheels are straight ahead. Which is the correct correction?

  1. Replace the drag link
  2. Reposition the steering wheel on the column splines after confirming the gear is centered Correct answer.
  3. Adjust the tie rod sleeves to move the wheel to center
  4. Turn the wheel to center and reset the spool valve

Explanation

The gear must be on its high point with the wheels straight, then the wheel is indexed to the column so the turn-signal cancel and clock spring align. Using the tie rods to center the wheel changes toe and can misposition the gear.

Question 38Steering Systems Diagnosis and Repair

A transit bus is equipped with a steering gear that has an adjustable worm bearing preload. The driver reports a slight bind when the wheel passes through the straight-ahead position. Which condition is most likely?

  1. Insufficient sector shaft end play
  2. A worn pitman arm spline
  3. Low tire pressure
  4. Excessive worm bearing preload Correct answer.

Explanation

Too much worm bearing preload causes binding that is often most noticeable near center where gear mesh is tightest. The other items produce different symptoms such as play, looseness, or high effort everywhere.

Question 39Steering Systems Diagnosis and Repair

During diagnosis of a transit bus that pulls to one side, the technician notes that the pull disappears when the power steering return line is temporarily restricted to equalize assist. Which conclusion is best supported?

  1. The tie rod ends are worn
  2. The steering gear spool valve or centering is biased Correct answer.
  3. The front alignment is incorrect
  4. The pump relief pressure is too high

Explanation

If equalizing hydraulic assist removes the pull, the cause is hydraulic bias in the gear valve rather than a mechanical alignment problem. Alignment and worn linkage would continue to pull regardless of assist balance.

Question 40Steering Systems Diagnosis and Repair

A transit bus has a steering system complaint after a rebuilt steering gear was installed. The technician finds the wheel turns easily in one direction and is hard to turn in the other, and the gear was installed without centering the spool valve per the service procedure. Which is the most likely result of this error?

  1. The steering damper will become inoperative
  2. The toe setting will change on its own
  3. The pump will fail immediately from overpressure
  4. The gear will self-steer or provide unequal assist until the valve is centered Correct answer.

Explanation

An off-center spool valve biases hydraulic assist, producing unequal effort or self-steering. Pump failure, toe change, and damper failure are not consequences of valve centering.

Question 41Steering Columns, Linkages, and Power Steering Components

On a heavy transit bus with a hydraulic power steering system, what is the primary function of the power steering pump?

  1. To lubricate the steering column bearings under pressure
  2. To generate electrical current for the steering control module
  3. To circulate engine coolant through the steering gear housing
  4. To pressurize hydraulic fluid that assists the steering gear Correct answer.

Explanation

The power steering pump draws fluid from the reservoir and delivers it under pressure to the steering gear, where the pressure acts on the piston or rotary valve to assist steering effort. It does not cool the engine, generate electricity, or lubricate column bearings.

Question 42Steering Columns, Linkages, and Power Steering Components

A transit bus operator reports that steering effort is normal when turning right but much higher when turning left. Which condition best explains this?

  1. Low tire pressure on the right front tire
  2. A worn idler arm bushing
  3. A faulty pressure control valve inside the steering gear Correct answer.
  4. A binding steering column upper bearing

Explanation

Asymmetric assist in a hydraulic steering gear typically points to an internal fault such as a sticking or misadjusted pressure control valve or a damaged piston seal that only affects one direction. Column bearings, tire pressure, and idler bushings would generally affect effort in both directions.

Question 43Steering Columns, Linkages, and Power Steering Components

What is the purpose of the torsion bar in an integral power steering gear?

  1. To sense steering input torque and position the rotary valve Correct answer.
  2. To damp road shock transmitted to the steering wheel
  3. To return the steering wheel to center after a turn
  4. To limit maximum steering angle at full lock

Explanation

The torsion bar twists in proportion to driver input torque; this twist moves the rotary valve relative to the worm or input shaft, directing pressurized fluid to the correct side of the piston. Return-to-center is provided by caster and the gear's centering springs, not the torsion bar alone.

Question 44Steering Columns, Linkages, and Power Steering Components

During a road test, a transit bus steering wheel has excessive free play before the front wheels begin to move. Technician A says this could be caused by a worn drag link. Technician B says this could be caused by a loose steering gear mounting. Who is correct?

  1. Neither technician
  2. Technician A only
  3. Both Technician A and Technician B Correct answer.
  4. Technician B only

Explanation

Excessive free play can come from wear anywhere in the linkage between the wheel and the road wheels, including the drag link, tie rod ends, and pitman arm, as well as from a loose gear box or worn gear internals. Both technicians describe valid causes.

Question 45Steering Columns, Linkages, and Power Steering Components

Which component converts the rotary motion of the steering wheel into linear motion that moves the steering linkage?

  1. The idler arm
  2. The steering knuckle
  3. The tie rod sleeve
  4. The steering gear Correct answer.

Explanation

The steering gear reduces and redirects steering wheel rotation into linear movement of the pitman arm or rack, which then drives the linkage. The knuckle pivots on the ball joints, the idler arm supports the linkage, and the tie rod sleeve is only an adjustment device.

Question 46Steering Columns, Linkages, and Power Steering Components

A transit bus equipped with a hydraulic retarder and power steering exhibits a whining noise from the pump that increases with engine speed and is accompanied by foamy fluid in the reservoir. What is the most likely cause?

  1. An over-tight power steering belt
  2. A worn steering gear pitman shaft seal
  3. Air being drawn into the pump suction line Correct answer.
  4. A restricted return line to the reservoir

Explanation

Foamy fluid and speed-related whine indicate aeration, usually from a loose or cracked suction hose or a low fluid level allowing the pump to draw air. A restricted return line causes high back pressure and leaks rather than foam, and a tight belt would squeal rather than foam the fluid.

Question 47Steering Columns, Linkages, and Power Steering Components

What is the correct procedure for adjusting the preload on a recirculating ball steering gear's sector shaft?

  1. Turn the sector shaft adjusting screw clockwise until it bottoms, then back off two turns
  2. Loosen the locknut, turn the adjusting screw in until slight drag is felt at the center position, then tighten the locknut Correct answer.
  3. Tighten the adjusting screw fully and check for binding at full lock
  4. Back the adjusting screw out until all free play is removed from the steering wheel

Explanation

Sector shaft preload is set with the gear at its center (high point) position so that a slight drag is felt through the wheel, then the locknut is tightened while holding the screw. Bottoming the screw or setting it at full lock causes binding and accelerated wear.

Question 48Steering Columns, Linkages, and Power Steering Components

A transit bus uses a linkage-type power steering system with a hydraulic assist cylinder. Where is the control valve typically located?

  1. On the drag link or the steering gear output Correct answer.
  2. Inside the power steering fluid reservoir
  3. Inside the steering column near the lock cylinder
  4. At the assist cylinder rod end

Explanation

In linkage-type (power-assisted) systems, the control valve is commonly mounted on the drag link or integrated with the steering gear output so it senses the force in the linkage. It is not in the column, at the cylinder rod end, or in the reservoir.

Question 49Steering Columns, Linkages, and Power Steering Components

Which of the following best describes the purpose of a steering damper on a heavy transit bus?

  1. To center the steering wheel after a turn
  2. To reduce shimmy and kickback transmitted through the steering linkage Correct answer.
  3. To increase steering assist at low engine speed
  4. To limit the maximum steering angle

Explanation

A steering damper is a hydraulic shock absorber in the steering linkage that controls oscillations such as shimmy and absorbs road shock before it reaches the driver. It does not change assist level, provide centering, or set steering limits.

Question 50Steering Columns, Linkages, and Power Steering Components

A transit bus has a complaint of steering wander at highway speed. During inspection, the technician finds the front axle thrust angle is within specification and the gear is properly adjusted. Which condition should be checked next?

  1. Excessive caster angle on both front wheels
  2. Worn center link and tie rod ends allowing lateral play Correct answer.
  3. Power steering pump relief pressure set too high
  4. Steering wheel horn contact resistance

Explanation

Wander with a correctly adjusted gear and acceptable thrust angle often comes from loose linkage that lets the wheels move independently of the steering wheel. Excessive caster would increase straight-line stability rather than cause wander, and pump relief pressure or horn contacts do not affect wander.