If you drive or manage a commercial truck in California, you must follow specific safety laws, and one of the most important is the 90-Day BIT Inspection.
BIT stands for Basic Inspection of Terminals, and it’s a required check that occurs every 90 days to ensure your truck is safe, legal, and road-ready.
You might be wondering:
- What exactly do inspectors look at during this inspection?
- Why is it so important?
- How can I ensure a stress-free experience and avoid unexpected issues during the inspection?
This blog answers those questions in a simple, clear, and easy-to-follow way — no complicated language, just straight facts and useful tips.
Whether you're a one-truck owner-operator or someone managing a whole fleet of trucks, this guide will help you understand, prepare, and pass your BIT inspection with confidence.
What Is a BIT Inspection?
A BIT Inspection (Basic Inspection of Terminals) is a safety check that’s required by California law for commercial trucks. It has to be done every 90 days (that’s four times a year) to make sure the truck is in good shape and safe to drive.
It’s required by the California Highway Patrol (CHP).
If your truck is used for business and it weighs more than 10,000 pounds, it likely needs a BIT inspection — even if it looks fine or runs well.
Why is it important?
Because of the inspection:
- Make sure the brakes, tires, lights, and safety systems are all working right
- Helps prevent accidents caused by mechanical failures
- Keeps your truck legal on the road
- Protects you from fines or being pulled out of service
Bottom line:
If you skip your 90-day BIT inspection, you could face big penalties, risk unsafe driving, and even have your truck shut down by the CHP.
Who Can Perform a BIT Inspection? – Easy Explanation
Only certified personnel are legally allowed to perform a 90-day BIT inspection. It has to be done by someone who is:
✅ Certified
✅ Experienced
✅ Legally approved
This means the person inspecting your truck must be a qualified mechanic who knows how to check brake systems, safety equipment, tires, lights, and more. They need to understand how a commercial truck works and what the law requires.
You can’t do the inspection yourself (unless you're certified), and it can’t be done by just any regular auto shop.
This underscores the importance of choosing a trusted and certified facility, such as:
➡️ Flying Bird Truck Repair in Bakersfield, CA
They are trained, certified, and approved to perform official BIT inspections—and they’ll make sure your truck is 100% road-legal.
What Gets Checked During a BIT Inspection?
Let’s break down the key components of a BIT inspection.
1. Brake System
Your truck’s braking system is a major safety concern.
Inspectors will check:
- Air brake system and compressor operation
- Brake chambers and slack adjusters
- Brake shoes, pads, and drums
- Leaks in brake lines or air hoses
- Proper brake adjustment and function
Tip: Uneven wear or leaking air lines are common reasons for failure.
2. Steering and Suspension
The inspector will examine:
- Steering gearboxes and linkages
- Power steering fluid levels and leaks
- Shocks, struts, and suspension springs
- Kingpins and ball joints
- U-bolts and hangers
Any looseness, cracks, or excessive play will be flagged immediately.
3. Lights and Reflectors
All external lights must be working, including:
- Headlights (high and low beam)
- Brake lights
- Turn signals and hazard flashers
- Tail lights
- Marker and clearance lights
- Reflectors and reflective tape
Pro Tip: Clean all lenses before inspection. Dirty or faded lights can still count as violations.
4. Tires and Wheels
Tire and wheel checks include:
- Front tires require a minimum tread depth of 4/32”, while rear tires need 2/32”. This is a critical aspect of tire inspection.
- Proper inflation
- No cuts, bulges, or exposed belts
- No mismatched or damaged rims
- No missing lug nuts or studs
5. Frame and Chassis
Inspectors look for:
- Cracks or damage in the frame
- Loose or broken cross-members
- Rusted or bent frame rails
- Secure mounting of fuel tanks and battery boxes
6. Exhaust System
Exhaust components must:
- Be securely mounted
- Have no leaks or holes
- Be free from tampering or illegal modifications
- Be properly routed away from fuel tanks and the cab
Leaks are often indicated by the presence of black soot around joints.
7. Fuel System
Inspected for:
- Leaks in fuel lines
- Properly secured tanks and caps
- No damage or corrosion
Any signs of dripping fuel will fail your inspection.
8. Driveline and Transmission
Here’s what they check:
- Driveshaft and U-joints
- Transmission fluid leaks
- Mounting brackets and supports
- Signs of excessive wear or play
9. Horn, Wipers, and Mirrors
Yes—these small details matter:
- The horn must be loud and working
- Wiper blades must clear the windshield
- Mirrors must be secure and crack-free
Even a broken mirror can cause a failed inspection.
10. Emergency Equipment
You’re required to carry:
- Fire extinguisher (charged and mounted)
- Three reflective warning triangles
- Spare fuses (if used)
Paperwork and Records
The BIT Inspection also includes document checks, including:
- Current registration and insurance
- Maintenance logs
- Previous inspection records
- Driver vehicle inspection reports (DVIRs)
Keep everything neat, organized, and accessible. Inspectors don’t like digging through a mess.
Common Reasons Trucks Fail BIT Inspections
Avoid these common mistakes:
❌ Leaking brake lines
❌ Bald or underinflated tires
❌ Broken lights or reflectors
❌ Worn-out wipers
❌ Loose steering components
❌ Missing documentation
How to Prepare for a BIT Inspection
To increase your likelihood of passing, follow these guidelines:
✅ 1. Do a Pre-Inspection
Before your official BIT inspection, take a few minutes to walk around your truck and check all the important parts yourself.
Look for:
- Worn-out tires
- Burned-out lights
- Air or fluid leaks
- Brake issues
Why? Because if you spot a problem early, you can fix it before the inspector sees it.
✅ 2. Fix Small Issues Early
Don’t wait until inspection day to deal with a loose wire, low tire, or small oil leak.
Even little things can cause you to fail a BIT inspection.
Tip: Taking care of problems early can save you time, stress, and money later.
✅ 3. Keep Your Records Clean
The inspector may ask to see:
- Your maintenance history
- Past inspection reports
- Driver reports
- Service logs
Keep these documents organized and ready. Messy or missing paperwork could cause issues, even if your truck is in great shape.
✅ 4. Choose a Certified Shop
Not every repair shop is allowed to do a BIT inspection.
Always go to a certified, trusted shop, like Flying Bird Truck Repair in Bakersfield.
They know exactly what CHP wants, and they’ll help you pass the inspection with no guesswork.
✅ Summary:
Doing a little prep before your BIT inspection helps you avoid failures, fines, and downtime.
Consider it a safety tune-up—your future self will appreciate it!
How Often Are BIT Inspections Required?
California law requires BIT inspections every 90 days for each commercial vehicle. That means four times per year. No exceptions.
Even if the truck sits idle, the clock keeps ticking.
Where to Get a BIT Inspection in Bakersfield, CA?
Look no further than Flying Bird Truck Repair.
We offer:
✔️ Certified BIT Inspections
✔️ Fast turnaround and fair pricing
✔️ Diesel repair, diagnostics, and emergency service
✔️ Fleet services and compliance help
Address: 681 Pepper Dr, Bakersfield, CA 93307
Phone: +1 661-567-0020
Final Thoughts
The BIT Inspection may seem intimidating at first, but once you understand what gets checked and how to prepare, it becomes just another part of responsible trucking.
It’s not about passing a test — it’s about keeping you, your cargo, and everyone else on the road safe.
Let professionals like Flying Bird Truck Repair take the stress out of your 90-day inspections, so you can stay focused on what you do best: driving.
Ready to schedule your next BIT Inspection?
✅ Call today or book online. We'll get you in, inspected, and back on the road fast!
