How to Use the AUTOOL SML330 Smoke Leak Detector

The AUTOOL SML330 is an automotive smoke leak detector. This guide turns the current model-specific controls and official operating sequence into a practical start-to-finish workflow.

Before you start

Work in a clean, well-lit and ventilated area. Stabilize the vehicle, keep rotating or hot components out of the work zone, and open the exact vehicle procedure for the system and test point you will use. A tool connection is not automatically safe just because an adapter fits.

• confirm that the model label reads AUTOOL SML330 and that the controls match this guide;
• inspect the housing, cables, clamps, hoses, fittings, seals and adapters for damage or contamination;
• identify the permitted connection point, test range, vehicle state and acceptance criteria before connecting;
• keep eye protection and the task-appropriate gloves within reach; and
• plan how you will return the vehicle circuit or line to its original sealed condition after the test.

Use the AUTOOL manual download center to locate the current instructions when a manual is available. The delivered model label and current vehicle service information control if an older image or remembered setting differs.

SML330 controls and specifications

The AUTOOL SML330’s key controls and functions include Two Testing Modes, Rapid Pipeline Leak Detection, Overheat Protection, Power Source, Large Smoke Output Volume. Confirm each relevant control on the physical unit before use; related models can look similar while using different ranges, air sources or operating modes.

Specification or function	Current model
Rated Power	65W
Power Supply	DC 12V/5A
Air Source	Built-in air pump
Output Pressure	<15psi
Gross Weight / Net Weight	3.7kg / 3.2kg
Main Unit Size	250x160x165mm
Output Flow Rate	<6L/min
Packaging Size	295x295x205mm

Stay inside both limits: the tool’s rated range and the vehicle or component’s permitted test range. When they differ, the lower applicable limit is the boundary. Do not infer a missing gauge, adjustment, mode or protection feature from a higher model in the same series.

How to use the SML330

Step 1: Confirm the exact SML model and permitted test circuit

Match the data plate, power lead, smoke hose, flow control, gauge and adapters to the exact SML310, SML330, SML400 or SML500. Identify the circuit and its safe test boundary from current vehicle information; do not connect to a hot exhaust, pressurized fuel circuit, high-voltage enclosure or any passage that the vehicle procedure excludes.

Before moving on, pause and check the connection against the physical labels. A secure-looking connection can still be the wrong port, polarity, range or adapter.

Step 2: Secure and cool the vehicle

Park in a ventilated area, apply the parking brake and switch the engine off. Let the intake, exhaust and nearby components cool, keep ignition sources away and isolate any fan, belt or actuator that could move during the test.

Step 3: Inspect the machine and use only approved smoke fluid

Check the housing, lead, clips, fuse, hose, nozzle, gauge, flow control and seals for damage or contamination. Add only the smoke fluid permitted by the exact SML instructions and stay within the marked fill range; do not substitute fuel, solvent, coolant or workshop oil.

Step 4: Prepare a bounded test section

Choose the smallest useful section of the intake, EVAP or other supported low-pressure circuit. Remove caps or hoses only by the vehicle procedure, install the correct adapter without damaging a seal and close only the openings that must be closed for this named test.

Step 5: Connect power with correct polarity

Keep the machine upright and connect it to the exact supported vehicle supply, red to positive and black to negative unless the delivered label states otherwise. Route the lead and hose away from hot, sharp and moving parts and confirm the normal power indication before generating smoke.

Step 6: Run the air or flow check first

Use the machine's air mode or initial flow indication, where fitted, to confirm the setup is connected and to estimate whether the circuit has a large opening. Stop for a blocked hose, unstable gauge, fluid leak, overheated lead or unexpected pressure rather than increasing output blindly.

Step 7: Introduce smoke at the lowest effective setting

Start smoke generation and use only the output permitted for the selected circuit. Watch every connection and allow smoke time to travel through the bounded section; higher pressure does not make a test more accurate and can damage valves, diaphragms or seals.

Step 8: Trace the first visible escape point

Inspect under good light from the connection outward, using the flow indication and visible smoke together. Check hose joints, caps, seams and components from more than one angle. Record the first repeatable escape point, because smoke drifting from another area can make the final plume misleading.

Step 9: Isolate and confirm the suspected leak

Stop output, let smoke clear as needed and change only one connection or section at a time. Repeat the same controlled test to confirm the leak belongs to that component or joint; a smoke plume shows an escape path but does not by itself identify why the part failed.

Step 10: Shut down and restore the vehicle

Stop smoke generation, disconnect power by the insulated clips and allow the machine and circuit to return to a safe state before removing adapters. Restore every hose, cap, connector and clamp, clear any fault created for testing and complete the vehicle-specific functional or leak verification.

Do not end the job at the first plausible indication. Repeat or confirm the observation under the same controlled condition, then restore the vehicle connection and check for leakage, warnings or an abnormal response.

Read and verify the result

Compare the observation with known conditions, not with a single memorized number. Check whether the reading, indication or visible result is stable, repeatable and produced with the correct setup. If possible, compare a known-good point or repeat after correcting one controlled variable.

• A repeatable result at the correct connection is stronger evidence than a momentary spike or one brief indication.
• An out-of-range result can identify a direction for diagnosis, but it does not name the failed component by itself.
• A normal result at one test point does not clear every part of the system; follow the vehicle diagnostic tree.
• After a repair, repeat the same controlled test and complete the vehicle-specific functional check.

Common mistakes and care

• Use only the approved smoke fluid and the exact model's supported power and pressure boundary.
• Never smoke-test a hot exhaust, pressurized fuel path, high-voltage enclosure or unidentified circuit.
• Keep the machine upright, ventilate the work area and stop for heat, odor, leakage or unstable pressure.
• A visible plume locates an escape path; confirm the component and failure cause separately.
• Do not borrow a range, mode, connection order or interpretation rule from another model in the series.
• Do not disconnect a live electrical, pressure, vacuum or fluid connection; first return the tool and vehicle system to a safe state.
• After use, clean only as directed, keep ports capped, coil leads and hoses without sharp bends, and store the kit dry.

Frequently asked questions

Can I use the SML330 setup from a different AUTOOL model?

No. Similar housings and accessories do not prove identical ranges, controls, power requirements or connection methods. Match the exact model first.

Does one normal result prove the system is fault-free?

No. It proves only that the tested condition was within the chosen acceptance criteria at that moment. Continue the vehicle-specific diagnostic path when the symptom remains.

What should I do when the reading is unstable?

Stop and check power, connection security, sealing, range selection, test-point suitability and vehicle state. Repeat only after the cause of instability is understood.

Final SML330 checklist

• Exact model, permitted test point and test range confirmed
• Tool, leads, hoses, seals and adapters inspected
• Setup completed in the model-specific sequence
• Observation repeated or otherwise verified
• Vehicle connection restored with no leaks, loose terminals or open ports
• Tool shut down, cleaned and stored without trapped pressure or unsafe power

Used this way, the SML330 supports a disciplined diagnostic decision: prepare the correct test, control the setup, verify the observation and leave the vehicle in a known safe state.