PM3 Generator Inspection
PM3 Generator Service
PM2 + Coolant, Hoses, Gaskets, and Thermostats Replacement
Every three to six years, we perform our most comprehensive service. This Preventative Maintenance 3 includes all PM1 & PM2 items plus replacement of coolant, hoses, gaskets, and thermostats.
This systematic approach ensures no component is overlooked and provides a complete picture of your generator’s health. Each inspection item has been carefully selected based on decades of field experience and manufacturer recommendations.
What’s Included: The Complete 31-Point PM1 Inspection
Every PM3 service starts with our comprehensive 31-Point Inspection process. During this inspection, our EGSA-certified technicians thoroughly evaluate every critical system and component of your generator. This major service interval goes beyond routine maintenance to include critical component replacements that restore your generator to peak operating condition and extend its service life for years to come.
Plus PM2 Annual Service Items
In addition to the complete 31-Point Inspection, a PM2 includes these critical annual service tasks:
What Makes PM3 Different: Major Service Components
PM3 addresses the critical wear items that degrade over years of operation. These components have longer service intervals but are essential for reliable performance and preventing catastrophic failures.
- Coolant Change
- Hoses
- Gaskets
- Thermostats
Coolant Change
Fresh coolant replacement during PM3 service restores critical corrosion inhibitors and anti-degradation additives that break down over time. Old coolant loses its ability to prevent electrochemical degradation—a leading cause of hose and gasket failure—and can no longer maintain optimal engine operating temperatures. A PM3 coolant flush removes accumulated contaminants, rust particles, and deposits that reduce cooling efficiency and clog radiator cores and is available when necessary.
Hoses
PM3 service replaces all major rubber cooling system hoses that deteriorate from constant exposure to heat, pressure, and vibration. This typically includes:
- Air Intake Hoses (when needed)– Flexible connections between turbocharger, intercooler, and intake manifold
- Upper and Lower Radiator Hoses – Transfer coolant between the engine and radiator
- Bypass Hose(s) – Route coolant back to the engine during warm-up when the thermostat is closed
- Heater Hoses – Supply heated coolant to the block heater or jacket water heater system
- Fuel Lines – Rubber fuel supply and return lines exposed to diesel and pressure
Gaskets
Critical sealing gaskets replaced during PM3 prevent coolant and oil leaks at component mating surfaces:
- Thermostat Housing Gasket – Seals the thermostat housing to the water pump or engine block
- Thermostat O-ring/Seal – Provides secondary sealing around the thermostat element itself
- Radiator Cap – Maintains proper cooling system pressure
Thermostats
Most commercial generators have one primary thermostat, though some larger engines (like Cummins 8.3L) may have dual thermostats for improved flow control. The thermostat is typically located in a housing near the engine’s coolant outlet, often positioned:
- At the front of the engine near the water pump
- Behind or adjacent to the alternator mounting bracket
- Connected to the upper radiator hose
Thermostats regulate coolant flow to maintain optimal operating temperature (typically 180-200°F). PM3 replacement includes new thermostat gaskets to prevent leaks at the housing interface.
Recommended PM Schedule
(PM1 + All Filters & Oil Change)
(PM2 + Coolant, Hoses, Gaskets & Thermostats Change)
Still have questions or looking for more information?
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