CAT Fault Code
Free · no signupSPN 101 FMI 15
Oil Leaking from Breather.
System
Engine
Symptom
Oil Leaking from Breather.
Diagnosis & fix steps
LOGIC: High Crankcase Pressure.
ACTION: Change the Crankcase Breather Filter (Coalescer). Check for excessive "Blow-by."
Red Seal field insights
RED SEAL FIX: If the filter is new and pressure is still high, a piston ring is likely cracked or stuck.
Track this across your whole fleet
This code is free to read. AM Fleet Integrity lets your team log fault codes against assets, plus the full fault-code library, QR operator reporting, PM scheduling and predictive alerts. Start free — no credit card required.
Start your free trial