Caterpillar Off highway tractors

Coolant capacity & service interval

Caterpillar Off highway tractors utilize coolant with a capacity range of 232 to 268 liters. Service intervals include checks every 10 hours and changes at 36 months/6000 hours or 72 months/6000 hours. The data covers 6 configurations.

The configuration chart below lists fill volumes and service intervals for each engine and trim variant.

TypeSpecifications
777G, RDR (2012- )
  • Use: Normal
  • Capacity 240 liter
  • Check 10 hours
  • Change 36 months/ 6000 hours
777G, T4Y (2012- )
  • Use: Normal
  • Capacity 240 liter
  • Check 10 hours
  • Change 36 months/ 6000 hours
777G, T5A (2012- )
  • Use: Normal
  • Capacity 240 liter
  • Check 10 hours
  • Change 36 months/ 6000 hours
777G, TNM (2012- )
  • Use: Normal
  • Capacity 240 liter
  • Check 10 hours
  • Change 36 months/ 6000 hours
777F, JXP (2007- )
  • Use: Normal
  • Capacity 232 liter
  • Check 10 hours
  • Change 36 months/ 6000 hours
776D
  • Use: Normal
  • Capacity 268 liter
  • Check 10 hours
  • Change 72 months/ 6000 hours

Additional Notes

  • The Caterpillar 776D cooling system holds 268 liters, which is notably larger than the 777-series capacities listed. A higher coolant volume generally reflects a larger or more thermally demanding engine configuration requiring greater heat dissipation capacity.
  • The 777F (JXP serial prefix, from 2007) carries a 232-liter cooling system capacity, while all four 777G configurations (RDR, T4Y, T5A, TNM, from 2012) share a uniform 240-liter capacity. The 8-liter difference between the 777F and 777G indicates a modest increase in coolant volume across the model generations.
  • All four 777G serial prefix variants share identical cooling system specifications: 240-liter capacity, a 10-hour check interval, and a change interval of 36 months or 6,000 hours. The consistency across RDR, T4Y, T5A, and TNM prefixes suggests a standardized cooling architecture across 777G production configurations.
  • The 776D carries a change interval of 72 months or 6,000 hours under normal use conditions. The 72-month calendar limit is double that of the 777F and 777G models, which are both set at 36 months or 6,000 hours. When the hour threshold is the same but the calendar limit differs, the calendar interval becomes the determining factor for lower-utilization machines that accumulate hours slowly.
  • All models in these specifications share a 10-hour coolant check interval under normal use conditions. On large off-highway equipment, a 10-hour check cycle aligns with roughly daily inspections during continuous operation, allowing early detection of coolant level loss or contamination before a full service interval is reached.
  • The 6,000-hour change interval applied across the 777F and all 777G variants is a relatively extended service interval for heavy equipment cooling systems, typically associated with the use of extended-life coolant (ELC) formulations. Standard conventional coolants in heavy equipment generally require changes at shorter hour intervals.

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