ASE Practice Test (G1: Auto Maintenance & Light Repair) 3 Flashcards

A customer asks when they should have their automatic transmission fluid (ATF) changed. What is the BEST answer?

Answer: Follow the vehicle manufacturer's service interval — many specify a change at 30,000–60,000 miles for severe service or as determined by fluid condition inspection

ATF degrades over time from heat and oxidation, losing its viscosity, friction modifier properties, and anti-wear additives. Manufacturers specify service intervals that vary by model and service conditions. "Severe service" (frequent towing, city driving, high temperatures) requires more frequent changes. Inspecting the fluid — checking color (should be reddish, not dark brown or black) and smell (should not smell burned) — helps determine condition. Neglecting ATF changes accelerates transmission wear.

When replacing wiper blades, a customer reports the new blades are still streaking. What should the technician check?

Answer: Clean the windshield thoroughly with glass cleaner to remove wax, oil film, or silicone residue that causes streaking regardless of blade condition

Wiper streaking after new blade installation is frequently caused by windshield contamination rather than faulty blades. Wax, silicone from detailing products, oil film from rain repellents, and road grime create a hydrophobic layer that prevents the blade from wiping cleanly. Cleaning the windshield with a dedicated glass cleaner (not one with silicone or wax) and wiping the blade rubber with a clean cloth typically resolves streaking. If streaking continues on a clean glass, the wiper arm pressure or blade type may be wrong.

What is the purpose of power steering fluid in a hydraulic power steering system, and what are signs of low or degraded fluid?

Answer: It transmits hydraulic force from the pump to the steering gear to assist steering; signs of low/degraded fluid include hard steering, whining noise from the pump, and fluid leaks

Hydraulic power steering uses a pump to pressurize fluid, which applies force to assist the rack-and-pinion or recirculating ball steering gear. Low fluid reduces hydraulic pressure, making steering heavy, especially at low speeds. A whining or groaning noise from the pump indicates cavitation from low fluid or aeration. Dark, dirty fluid has degraded additives and may contain moisture, promoting corrosion in the pump and steering gear. Fluid level and condition should be checked regularly.

A customer's battery requires jump-starting frequently. The battery is only 2 years old. What should the technician test FIRST?

Answer: Test the charging system (alternator output voltage and current), then load-test the battery to evaluate its condition

Frequent need for jump-starting can indicate a failing battery, an undercharging alternator, or a parasitic electrical drain. Testing the charging system first (alternator should produce 13.5–14.7V at idle) determines if the battery is being recharged properly. A load test on the battery measures its ability to deliver current under load. If the alternator is undercharging, the battery repeatedly discharges. If the alternator is fine and the battery fails a load test, replacement is indicated.

What does the brake fluid DOT rating indicate?

Answer: The fluid's dry and wet boiling point specifications — higher DOT numbers indicate higher boiling points and better performance

DOT (Department of Transportation) brake fluid ratings specify minimum boiling points under dry (fresh fluid) and wet (fluid with 3.7% absorbed water) conditions. DOT 3 has the lowest boiling points; DOT 4 and DOT 5.1 are progressively higher. Higher boiling points provide greater resistance to vapor lock under severe braking. All DOT 3, 4, and 5.1 are glycol-based and compatible. DOT 5 is silicone-based and NOT compatible with glycol-based systems.

When should a technician recommend replacing coolant hoses even if they appear externally undamaged?

Answer: When the hoses feel soft and spongy when squeezed, show signs of internal electrochemical degradation, or have reached the manufacturer's service interval

Coolant hoses degrade from the inside out. Electrochemical degradation (caused by stray electrical current in the cooling system from improper grounding) attacks the inner liner. External inspection may appear normal while the inside is soft and near failure. Squeezing the hose reveals softness that indicates internal breakdown. Many manufacturers recommend coolant hose inspection every 2 years or 30,000 miles, and replacement based on condition or at coolant change intervals regardless of appearance.