11/08/2026 10:54 am
Topic starter
Automotive Q&A
Why verify a smoke machine with a calibrated leak before testing the vehicle?
Review the evidence, add a focused answer, and distinguish confirmed measurements from assumptions.
Notifications
Clear all
Technician Exchange
2
Posts
2
Users
0
Reactions
126
Views
0
Two smoke machines show different flow-ball positions on the same EVAP system. Both produce visible smoke, but neither has been checked against its reference orifice recently. The shop needs a daily confidence check.
What should be verified and logged?
1 Answer
0
12/08/2026 7:35 am
With the machine at its specified pressure and warm-up state, connect the manufacturer's calibrated leak and record flow indication and pressure. Then block the outlet to confirm the system itself seals. Inspect hoses and adapters because a machine-side leak consumes flow before smoke reaches the vehicle. Use the correct reference size for the monitor threshold being investigated.
Visible smoke proves generation, not sensitivity. A reference check shows whether the machine can distinguish the leak size the diagnosis depends on.
Topic starter
13/08/2026 10:36 am
One machine failed the blocked-outlet test at a cracked hose near its case. After the hose repair, both machines indicated the same calibrated leak range. Daily checks are now logged before the first EVAP job.