21 Suspension, Steering, Wheels & Climate Parts Practice Questions & Answers

1. 1. A customer asks how to check a load-carrying ball joint that has a built-in wear indicator. What should the parts specialist tell him?

   • A.The indicator boss protrudes from the housing when the joint is good and sits flush when it is worn out.✓ Answer
   • B.The indicator boss sits flush with the housing when the joint is good and protrudes when it is worn out.
   • C.The indicator boss stays flush with the housing at all times and splits open when the joint is worn out.
   • D.The indicator boss protrudes from the housing at all times and changes color when the joint is worn out.

   The wear indicator is a boss or collar around the grease fitting that is manufactured proud of the joint housing. As the ball stud wears into its socket the stud moves up and the boss recedes, so the joint is checked with the vehicle's weight on the tires: flush or recessed means replace. The intuition runs backwards, which is why this is a classic counter question.

   Source: Official ASE Parts Specialist (P2) Study Guide, Vehicle Systems Knowledge: suspension, steering, and wheels components and reasons for replacementReport a problem with this question

2. 2. A customer asks what the nitrogen gas charge inside a gas-pressurized shock absorber actually does. Which answer is correct?

   • A.It keeps the damping oil under pressure so it resists foaming and aeration in hard use.✓ Answer
   • B.It carries part of the vehicle's weight, so a sagging spring is no longer felt in the ride.
   • C.It replaces damping oil that has escaped past a worn piston rod seal over time.
   • D.It softens the valving at low speed so the shock passes small bumps more quietly.

   The gas charge pressurizes the oil column so the oil does not cavitate or foam as the piston cycles rapidly; aerated oil is compressible and causes shock fade. Springs, not shocks, carry vehicle weight and set ride height, so a gas charge cannot correct a sagging spring.

   Source: Official ASE Parts Specialist (P2) Study Guide, Vehicle Systems Knowledge: shock absorber and strut construction and functionReport a problem with this question

3. 3. A customer buying a preassembled (loaded or quick) strut assembly asks what else is in the carton besides the strut unit. What does the assembly include?

   • A.A new coil spring, a new upper mount and bearing plate, and the spring seats.✓ Answer
   • B.A new steering knuckle, a new wheel hub bearing, and the knuckle mounting bolts.
   • C.A new stabilizer bar link, new bar bushings, and the link mounting hardware.
   • D.A new lower control arm, a new ball joint, and the control arm bushing set.

   The selling point of a loaded strut is that the spring is already compressed and captured on the strut with a new upper mount and bearing plate, so no spring compressor is needed and the wear items that fail alongside the damper are renewed at the same time. A worn bearing plate causes steering noise, binding, or failure to return to center.

   Source: Official ASE Parts Specialist (P2) Study Guide, Vehicle Systems Knowledge: strut service and related items sold with the repairReport a problem with this question

4. 4. A pickup sits well below specified ride height at both rear corners and the rear leaf springs have flattened out. Which parts does the counter person sell to restore ride height?

   • A.Rear leaf springs, sold and replaced as a pair.✓ Answer
   • B.Rear spring shackle bushings, sold as a complete set.
   • C.Rear stabilizer bar links, sold and replaced as a pair.
   • D.Rear shock absorbers, sold and replaced as a pair.

   Springs are the components that carry the vehicle's weight and therefore determine ride height; shocks, links, and bushings only control or locate motion. Sagging springs also change alignment angles and cause tire wear, and they are replaced in pairs so the vehicle sits level. On a torsion bar front suspension the equivalent low-ride-height fix is usually an adjustment rather than a part.

   Source: Official ASE Parts Specialist (P2) Study Guide, Vehicle Systems Knowledge: springs, ride height, and pair replacementReport a problem with this question

5. 5. A power steering pump is being replaced. Parts specialist A says the replacement pump may ship without a pulley, so the pulley must be transferred using a puller and installer. Parts specialist B says fresh fluid of the type the vehicle specifies should be sold with the pump. Who is right?

   • A.Neither A nor B
   • B.Both A and B✓ Answer
   • C.A only
   • D.B only

   Many replacement pumps are sold as a bare unit because one casting covers several pulley applications, so the pulley is pressed off the old pump and onto the new one with the proper tool — prying or hammering it on damages the new pump. Fresh fluid is also required, and the vehicle's specified fluid must be used because many systems need seal-conditioning additives that generic fluid or plain ATF does not have.

   Source: Official ASE Parts Specialist (P2) Study Guide, Vehicle Systems Knowledge: power steering pump replacement, related items, and fluidsReport a problem with this question

6. 6. A customer is replacing both outer tie rod ends himself. What should the parts specialist tell him about finishing the job correctly?

   • A.The wheels have to be rebalanced, because new tie rod ends change wheel runout.
   • B.A wheel alignment is required, because changing tie rod length changes toe.✓ Answer
   • C.Nothing further is needed if each new end is threaded on the same number of turns.
   • D.The steering wheel has to be recentered at the column rather than at the linkage.

   Tie rod length sets the toe angle, so any tie rod end, rack, or strut replacement must be followed by an alignment. Counting threads only approximates the old setting and cannot account for the wear that was present, and incorrect toe produces rapid feathered tire wear across the tread.

   Source: Official ASE Parts Specialist (P2) Study Guide, Vehicle Systems Knowledge: steering linkage parts and alignment as a related serviceReport a problem with this question

7. 7. A customer is fitting aftermarket alloy wheels that use a conical (60-degree tapered) lug seat, but his original lug nuts have a rounded ball seat. What should the parts specialist do?

   • A.Sell the original ball seat nuts together with a set of hub centric adapter rings.
   • B.Sell conical seat lug nuts that match the wheel, in the same thread size and pitch.✓ Answer
   • C.Sell the original ball seat nuts and have him torque them higher to compensate.
   • D.Sell flat mag seat nuts, which are designed to fit conical and ball seat wheels alike.

   The nut seat must match the wheel's seat geometry so the fastener centers the wheel and holds clamping load over the full seat area. A mismatched seat contacts on a narrow ring, loses clamp load as it beds in, lets the wheel loosen, and deforms the seat in the wheel; extra torque makes the damage worse, and centering rings address hub bore fit, not seat shape.

   Source: Official ASE Parts Specialist (P2) Study Guide, Vehicle Systems Knowledge: wheels, lug fasteners, and seat typesReport a problem with this question

8. 8. A customer asks what the offset stamped on a wheel means. Which statement is accurate?

   • A.It is the distance from the mounting face to the inboard edge of the rim.
   • B.It is the distance from the edge of the center bore to the outer rim face.
   • C.It is the distance from the wheel's centerline to the hub mounting surface.✓ Answer
   • D.It is the difference between the rim width and the tire's section width.

   Offset is measured from the wheel's centerline to the hub mounting pad: positive offset moves the mounting surface toward the street side and tucks the wheel inward, negative offset pushes the wheel outward. The distance from the mounting face to the inboard rim edge is backspacing, a different measurement, and changing either alters clearance to suspension parts and fender.

   Source: Official ASE Parts Specialist (P2) Study Guide, Vehicle Systems Knowledge: wheel fitment, offset, and backspacingReport a problem with this question

9. 9. A tire with a direct-reading TPMS sensor is being dismounted so the tire can be replaced. Which item should the parts specialist sell with that job?

   • A.A set of hub centric rings, which keep the sensor clear of the hub flange.
   • B.A sensor service kit with a new valve core, seal or grommet, nut and cap.✓ Answer
   • C.A replacement sensor battery, which is sold and installed as a separate item.
   • D.A brass valve core and cap, which are suitable for any aluminum valve stem.

   The sealing parts of a direct sensor are single-use, so the service kit is installed every time the tire is dismounted or the sensor is disturbed, and the stem nut is tightened to an inch-pound specification. The battery is sealed inside the sensor and is not serviceable, and a brass core in an aluminum stem sets up dissimilar-metal corrosion, which is why nickel-plated cores are supplied.

   Source: Official ASE Parts Specialist (P2) Study Guide, Vehicle Systems Knowledge: tire pressure monitoring sensors and related service itemsReport a problem with this question

10. 10. A tire sidewall is marked P215/65R16 98H. What do the last two characters, 98H, tell the parts specialist?

    • A.The load index of the tire and its speed rating.✓ Answer
    • B.The section width in millimetres and the construction type.
    • C.The aspect ratio of the tire and the rim diameter it fits.
    • D.The treadwear grade of the tire and its temperature grade.

    In the standardized sidewall designation the numeric group gives section width, aspect ratio, construction letter, and rim diameter, and the service description that follows gives the load index and the speed rating. The replacement rule for the counter is that a new tire must meet or exceed the original load index and speed rating, never fall below it.

    Source: Standardized U.S. tire sidewall designation as covered in the Official ASE Parts Specialist (P2) Study Guide, Vehicle Systems Knowledge: wheels and tiresReport a problem with this question

11. 11. This question contains the word EXCEPT. Read it carefully. All of these statements about an automotive air conditioning condenser are true EXCEPT:

    • A.It receives hot high-pressure refrigerant vapor from the compressor discharge line.
    • B.It releases heat to outside air and is normally mounted ahead of the radiator.
    • C.It cools the air entering the passenger compartment through the dash vents.✓ Answer
    • D.It changes the refrigerant from a vapor into a high-pressure liquid as it cools.

    The condenser is the high-side heat exchanger: it takes hot compressed vapor, gives up that heat to outside air, and condenses the refrigerant into a liquid. The component that cools and dehumidifies cabin air is the evaporator inside the HVAC case, and confusing the two is the classic counter error; a condenser blocked with bugs or debris simply reduces cooling capacity.

    Source: Official ASE Parts Specialist (P2) Study Guide, Vehicle Systems Knowledge: heating, ventilation, and air conditioning components and functionReport a problem with this question

12. 12. In a fixed-orifice-tube air conditioning system, where is the orifice tube located?

    • A.In the suction hose, between the evaporator outlet and the compressor inlet.
    • B.In the discharge hose, between the compressor outlet and the condenser inlet.
    • C.In the liquid line, between the condenser outlet and the evaporator inlet.✓ Answer
    • D.Inside the accumulator, at the outlet screen just ahead of the compressor.

    The orifice tube is the metering device, so it must sit at the boundary between the high and low sides — in the liquid line just ahead of the evaporator. Because its calibrated hole and inlet screen catch sludge and metal debris, it restricts both refrigerant and oil flow when it plugs, which is why it is always replaced after a compressor failure or any contamination.

    Source: Official ASE Parts Specialist (P2) Study Guide, Vehicle Systems Knowledge: air conditioning refrigerant circuit and metering devicesReport a problem with this question

13. 13. Why is the accumulator or receiver-drier replaced whenever an air conditioning system has been opened to the atmosphere?

    • A.Its pressure relief valve is designed to open only once and cannot reseat.
    • B.Its oil charge is consumed along with the refrigerant and cannot be topped up.
    • C.Its desiccant becomes saturated with moisture and cannot be dried out in service.✓ Answer
    • D.Its filter screen is the only part in the system able to trap metal debris.

    The desiccant bag holds a fixed capacity of moisture and begins absorbing humid air the moment the system is opened; once saturated it releases moisture back into the refrigerant, where it forms acids and sludge that attack the compressor and plug the metering device. The same part is replaced after a compressor failure and whenever the condenser or evaporator is replaced.

    Source: Official ASE Parts Specialist (P2) Study Guide, Vehicle Systems Knowledge: accumulator and receiver-drier function and replacementReport a problem with this question

14. 14. This question contains the word EXCEPT. Read it carefully. A compressor has failed and left metal debris in the system. All of these should be sold with the replacement compressor EXCEPT:

    • A.A can of stop-leak sealer to be added before the system is evacuated.✓ Answer
    • B.A new orifice tube or expansion valve along with a set of O-rings.
    • C.The correct type and quantity of refrigerant oil for that system.
    • D.A new accumulator or receiver-drier containing fresh dry desiccant.

    Repeat compressor failures are almost always caused by contamination left behind from the first failure, so the sale covers the drier, the metering device, O-rings, the specified oil, an approved flush of the hoses and evaporator, and often a belt. Sealer is not part of a proper repair: it circulates with the refrigerant and can plug the metering device, the new compressor, and recovery equipment.

    Source: Official ASE Parts Specialist (P2) Study Guide, Vehicle Systems Knowledge: air conditioning related items sold with a compressor replacementReport a problem with this question

15. 15. A customer wants to top off the compressor in an R-134a system with mineral oil left over from an older job. What should the parts specialist tell him?

    • A.R-134a systems take PAG oil of the specified grade, and mineral oil will not circulate.✓ Answer
    • B.R-134a systems accept any refrigerant oil, because the refrigerant carries it either way.
    • C.Mineral oil is the correct choice any time the compressor being installed is a new unit.
    • D.Mineral oil is acceptable in an R-134a system as long as only a small amount is added.

    Refrigerant oil has to be miscible with the refrigerant to be carried around the loop and back to the compressor. Mineral oil does not mix with R-134a, so it collects in the low spots and the compressor runs starved; R-134a systems use PAG of the viscosity the manufacturer calls out, retrofitted R-12 systems use POE or the specified PAG, and R-1234yf takes its own PAG that is not interchangeable.

    Source: Official ASE Parts Specialist (P2) Study Guide, Vehicle Systems Knowledge: air conditioning lubricants and refrigerant compatibilityReport a problem with this question

16. 16. A customer says the heater blower runs only on the highest fan speed and does nothing on the lower speeds. Which part should the parts specialist look up first?

    • A.The blower motor resistor or the fan speed control module.✓ Answer
    • B.The blower motor itself, together with its mounting gasket.
    • C.The blend door actuator that serves the heater case.
    • D.The cabin air filter listed for that model and its location.

    On most systems the highest fan speed feeds the motor directly and bypasses the resistor pack or control module, so the one speed that still works is the one that does not go through it. That makes the resistor or control module the part to quote, and the counter person should also offer the connector pigtail, which often overheats along with it.

    Source: Official ASE Parts Specialist (P2) Study Guide, Vehicle Systems Knowledge: heating and ventilation components and reasons for replacementReport a problem with this question

17. 17. A fastener is called out as M10 x 1.5 x 50. What does the 1.5 in that callout state?

    • A.The length in millimetres of the unthreaded shank under the head.
    • B.The distance in millimetres from one thread crest to the next crest.✓ Answer
    • C.The number of threads per inch counted along the threaded portion.
    • D.The strength class of the fastener in hundreds of megapascals.

    Metric fasteners are called out as M diameter x pitch x length, and pitch is a distance between adjacent threads, not a count. Inch fasteners are the opposite: 3/8-16 means sixteen threads per inch. Reversing the two definitions is a standard counter error, and inch and metric threads must never be forced into each other.

    Source: ISO metric screw thread designation convention, as covered in the Official ASE Parts Specialist (P2) Study Guide, Vehicle Systems Knowledge: fastener threads and sizesReport a problem with this question

18. 18. A customer needs a length of bulk heater hose and a length of steel brake tubing. How is each of the two sized at the counter?

    • A.Both are sized by outside diameter, since both are measured over the wall.
    • B.Hose is sized by outside diameter, and brake tubing is sized by inside diameter.
    • C.Both are sized by inside diameter, since both are rated by the flow they pass.
    • D.Hose is sized by inside diameter, and brake tubing is sized by outside diameter.✓ Answer

    Hose is specified by its inside diameter because that is the dimension that has to fit over the neck or nipple it clamps to, while tubing and tube fittings are specified by outside diameter because the flare and tube nut register on the outside of the tube. Mixing the two conventions is a common cause of a wrong part sold over the counter.

    Source: Official ASE Parts Specialist (P2) Study Guide, Vehicle Systems Knowledge: hose and tubing types, application, and sizingReport a problem with this question

19. 19. How is a replacement serpentine (multi-rib) drive belt specified at the parts counter?

    • A.By its top width and its outside circumference, the way a V-belt is.
    • B.By the number of ribs it carries and the belt's effective length.✓ Answer
    • C.By the number of pulleys the belt wraps in the engine's routing.
    • D.By the width of the crankshaft pulley the belt has to ride on.

    A multi-rib belt is identified by rib count and length, which is why the common size code reads as a number of ribs followed by a length figure; a V-belt instead uses top width and outside length. When selling one, ask about the automatic tensioner and idler pulleys, since a worn tensioner will destroy the new belt, and note that an elastic stretch-fit belt needs a special installation tool and must not be reused.

    Source: Official ASE Parts Specialist (P2) Study Guide, Vehicle Systems Knowledge: identifying and measuring special application beltsReport a problem with this question

20. 20. Parts specialist A says heater hose may be used as a fuel injection line as long as the diameter matches. Parts specialist B says heater hose may be used as PCV hose because both carry low pressure. Who is right?

    • A.Both A and B
    • B.B only
    • C.A only
    • D.Neither A nor B✓ Answer

    Hose must be matched to the fluid, pressure, and temperature it will see. Coolant hose is not fuel resistant and is nowhere near the pressure rating a port injection line needs, and it is also attacked by the oil vapor and blow-by in a PCV circuit, where it swells and softens. Fuel injection service requires hose built to the high-pressure fuel standard, and PCV service requires hose rated for oil vapor.

    Source: Official ASE Parts Specialist (P2) Study Guide, Vehicle Systems Knowledge: hose and tubing proper application and usageReport a problem with this question

21. 21. How is the length measured on a hex head cap screw, and how is it measured on a flat (countersunk) head screw?

    • A.Both are measured overall, from the top of the head to the tip.
    • B.Both are measured from under the head to the tip of the fastener.
    • C.The hex head is measured overall, and the flat head is measured under the head.
    • D.The hex head is measured under the head, and the flat head is measured overall.✓ Answer

    Length is measured to the part of the fastener that sits against the work: a hex, pan, or round head bears on top of the surface, so length starts under the head, while a countersunk head sinks flush into the material and is therefore measured overall. Using the wrong convention gives a fastener that either bottoms out or does not engage enough thread.

    Source: Official ASE Parts Specialist (P2) Study Guide, Vehicle Systems Knowledge: identifying fastener diameter, thread pitch, and lengthReport a problem with this question

Practice questions written to the ASE P2 Automobile Parts Specialist task list and standard parts-distribution practice. ASE is a mark of the National Institute for Automotive Service Excellence; this site is not affiliated with or endorsed by ASE. Part numbers, prices, warranty and return terms, and vehicle-specific applications are deliberately left out because they vary by supplier and change constantly — always confirm an application in your own current catalog and your employer's policies before selling a part. About the ASE P2 test →