Vehicle Inspection and Basic Control Cheat Sheet - Quick Reference Guide
Quick reference for the 7-step inspection method, critical defect thresholds, and basic control techniques from Sections 2.1-2.3 of the CDL manual. Use this for fast lookup during study and memorization of exam-critical information.
The 7-Step Inspection Method
| Step | Action | Key Items |
|---|---|---|
| 1 | Vehicle Overview | Check for leaks, damage, vehicle leaning, hazards |
| 2 | Engine Compartment | Fluids, belts, leaks, wiring |
| 3 | Start Engine/Cab | Gauges, controls, emergency equipment, ABS light |
| 4 | Lights Check | Low/high beams, flashers, turn signals |
| 5 | Walk-Around | Complete exterior inspection |
| 6 | Signal Lights | Brake lights, turn signals |
| 7 | Brake Tests | Hydraulic leak test, parking brake, service brake |
Critical Measurements to Memorize
| Item | Requirement |
|---|---|
| Front tire tread depth | 4/32 inch minimum |
| Other tire tread depth | 2/32 inch minimum |
| Steering wheel play | 10 degrees max (2 inches on 20" wheel) |
| Leaf springs missing | 1/4 or more = out of service |
| Air pressure build-up | 50-90 psi within 3 minutes |
| Governor cut-out | Typically 120-140 psi |
| First cargo inspection | Within 50 miles |
| Subsequent cargo checks | Every 150 miles or 3 hours |
Required Emergency Equipment
- Spare electrical fuses (unless circuit breakers)
- Three red reflective triangles (OR 6 fuses OR 3 liquid burning flares)
- Properly charged fire extinguisher
Tire Defects Checklist
| Defect | Action |
|---|---|
| Tread below minimum depth | Replace |
| Fabric showing through tread/sidewall | Out of service |
| Cuts, bulges, tread separation | Replace |
| Dual tires touching each other | Adjust/replace |
| Mismatched sizes | Not permitted |
| Mixed radial and bias-ply | Not permitted |
| Retreaded tires on bus front | Prohibited |
| Cut/cracked valve stems | Replace |
Suspension Defects
| Component | What to Check |
|---|---|
| Spring hangers | Movement allowing axle shift from position |
| Leaf springs | Cracked, broken, missing, or shifted leaves |
| Shock absorbers | Leaking |
| U-bolts | Cracked, damaged, missing |
| Torque rods/arms | Cracked, damaged, missing |
| Air suspension | Damaged or leaking |
Out of Service: 1/4 or more leaves missing from any leaf spring
Steering System Defects
- Missing nuts, bolts, cotter keys
- Bent, loose, or broken steering column
- Bent, loose, or broken steering gear box
- Bent, loose, or broken tie rods
- Power steering leaks (hoses, pumps)
- Low power steering fluid
- Steering wheel play over 10 degrees
Brake Defects
| Component | Defect |
|---|---|
| Drums | Cracked |
| Shoes/pads | Oil, grease, or brake fluid contamination |
| Shoes | Worn thin, missing, broken |
| Hoses | Wear from rubbing |
Exhaust System Defects
- Loose, broken, or missing pipes/mufflers/stacks
- Missing mounting brackets, clamps, bolts
- Parts rubbing against fuel system, tires, or moving parts
- Leaking exhaust (poison fumes can enter cab)
Engine Compartment Checks
| Item | What to Check |
|---|---|
| Engine oil | Level on dipstick |
| Coolant | Level, hose condition |
| Power steering fluid | Level, hose condition |
| Windshield washer fluid | Level |
| Battery | Fluid, connections, tie-downs |
| Belts | Tightness, wear |
| Leaks | Fuel, coolant, oil, hydraulic, battery |
| Wiring | Cracked/worn insulation |
Gauge Readings at Start-Up
| Gauge | Normal Reading |
|---|---|
| Oil pressure | Up to normal within seconds |
| Air pressure | 50-90 psi within 3 minutes |
| Ammeter/voltmeter | Normal range |
| Coolant temp | Gradual rise to normal |
| ABS light | On briefly, then OFF |
| Warning lights | Should go out |
Light Colors by Location
| Location | Required Color |
|---|---|
| Front (clearance, ID, markers) | Amber |
| Front turn signals | Amber or white |
| Side markers (front/middle) | Amber |
| Side markers (rear) | Red |
| Rear (clearance, ID, tail, brake) | Red |
| Rear turn signals | Red, yellow, or amber |
| Reflectors - front | Amber |
| Reflectors - rear | Red |
Brake Tests
Hydraulic Brake Leak Test
- Pump pedal 3 times
- Apply firm pressure
- Hold 5 seconds
- Pedal should NOT move
Parking Brake Test
- Set parking brake
- Put in low gear
- Gently pull forward
- Brake should hold
Service Brake Test
- Drive at 5 mph
- Apply brakes firmly
- Check for pulling to one side
- Check for unusual feel or delayed stopping
Backing Rules
| Rule | Reason |
|---|---|
| Start in proper position | Sets up safe backing path |
| Look at your path | Walk around, check clearances |
| Use BOTH mirrors | Blind spots on both sides |
| Back SLOWLY | Use lowest reverse gear |
| Back toward driver's side | Better visibility out side window |
| Use a helper | They see your blind spots |
| Agree on STOP signal | Most important signal with helper |
Key Rule: Back toward driver's side whenever possible. Go around the block if necessary.
Shifting Quick Reference
Double Clutching - Upshift
- Release accelerator + clutch to neutral
- Release clutch
- Let engine slow to next gear rpm
- Clutch + shift to higher gear
- Release clutch + accelerator
Double Clutching - Downshift
- Release accelerator + clutch to neutral
- Release clutch
- Increase engine rpm to match lower gear
- Clutch + shift to lower gear
- Release clutch + accelerator
When to Shift
| Method | How |
|---|---|
| RPM | Shift at top of operating range on tachometer |
| Road Speed | Learn speeds for each gear, use speedometer |
When to Downshift
- Before going down a hill (use lower gear than needed to climb)
- Before entering a curve (use power through curve)
Retarder Rules
| Condition | Retarder Setting |
|---|---|
| Dry road | ON (if desired) |
| Wet road | OFF |
| Icy road | OFF |
| Snow covered | OFF |
Warning: Retarders can cause drive wheel skids on slippery surfaces.
Acceleration Rules
| Condition | Action |
|---|---|
| Normal | Accelerate smoothly and gradually |
| Poor traction (rain/snow) | Accelerate very gradually |
| Wheels spinning | Take foot off accelerator |
| Starting on hill | Use parking brake to prevent rollback |
Walk-Around Inspection Path
Start: Left Front
→ Front
→ Right Front
→ Right Side
→ Right Rear
→ Rear
→ Left Side
→ Back to Cab
Quick Reference FAQs
Q: What's the minimum front tire tread depth?
A: 4/32 inch in every major groove.
Q: What's the minimum other tire tread depth?
A: 2/32 inch.
Q: How much steering wheel play is too much?
A: More than 10 degrees (about 2 inches on a 20-inch wheel).
Q: What puts a vehicle out of service for suspension?
A: 1/4 or more leaves missing from any leaf spring.
Q: Why back toward the driver's side?
A: Better visibility—you can see out the side window.
Q: When should you turn off retarders?
A: When the road is wet, icy, or snow covered.
Q: What gear for going down a hill?
A: Lower than the gear needed to climb the same hill.
Q: How do you test hydraulic brakes for leaks?
A: Pump 3 times, hold firm pressure 5 seconds—pedal should NOT move.
Q: What should the ABS light do at start-up?
A: Come on, then turn off. If it stays on, ABS is malfunctioning.
Q: How often to check cargo securement?
A: Within first 50 miles, then every 150 miles or 3 hours.
Key Points to Remember
- Safety is the most important reason for inspection
- Always inspect the same way every time so you don't miss items
- Touch/point and explain each item during CDL test
- Front tires need more tread depth (4/32") than others (2/32")
- 1/4 missing leaves = out of service
- 10 degrees steering play maximum
- Back toward driver's side for visibility
- Use lowest reverse gear when backing
- Downshift before hills and curves
- Retarders off on slippery roads
- Air pressure should build 50-90 psi in 3 minutes
Next Steps
Use this cheat sheet to memorize critical numbers and procedures:
- Memorize the 7 steps in order
- Know all the critical measurements
- Practice the brake tests
- Remember backing and shifting rules
Ready to test your knowledge? Start practicing with our Vehicle Inspection questions.
For detailed explanations, see our Complete Guide to Vehicle Inspection and Basic Control.