International Harvester 55 / 56

Coolant capacity & service interval

International Harvester 55 / 56 uses coolant with a capacity range of 21 to 33 liters. Service intervals include checks at 50 hours and changes at 1000 to 1200 hours. The data covers 9 configurations.

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

TypeSpecifications
856 XL, 856 XLA (1984-1985)
  • Use: Normal
  • Capacity 21 liter
  • Check 50 hours
  • Change 1200 hours
1056, 1056 XL (1982-1985)
  • Use: Normal
  • Capacity 24,4 liter
  • Check 50 hours
  • Change 1200 hours
956, 956 XL (1982-1985)
  • Use: Normal
  • Capacity 24,4 liter
  • Capacity 28,6 liter (+ airconditioning)
  • Check 50 hours
  • Change 1200 hours
1255 XL (1981-1985)
  • Use: Normal
  • Capacity 32 liter
  • Check 50 hours
  • Change 1200 hours
1455 XL (1981-1985)
  • Use: Normal
  • Capacity 33 liter
  • Check 50 hours
  • Change 1200 hours
1055 (1978-1981)
  • Use: Normal
  • Capacity 24,4 liter
  • Check 50 hours
  • Change 1200 hours
1255 (1978-1981)
  • Use: Normal
  • Capacity 31 liter
  • Capacity 33 liter (+ cabin)
  • Check 50 hours
  • Change 1000 hours
1455 (1978-1981)
  • Use: Normal
  • Capacity 31 liter
  • Check 50 hours
  • Change 1000 hours
955 (1978-1981)
  • Use: Normal
  • Capacity 23,8 liter
  • Check 50 hours
  • Change 1200 hours

Additional Notes

  • The International Harvester 1055 (1978-1981) and its successor variants, the 1056 and 1056 XL (1982-1985), share an identical cooling system capacity of 24.4 liters, despite spanning two distinct model generations separated by a specification update in 1982.
  • The 1255 (1978-1981) carries two listed capacity values: 31 liters as the base figure and 33 liters when a cabin is fitted. The additional 2 liters accounts for the coolant volume routed through the cabin heating circuit, which forms part of the cooling system loop.
  • The 1255 XL (1981-1985) lists a single capacity of 32 liters, a value that falls between the two figures recorded for the earlier 1255. The XL variant also carries a longer drain interval of 1200 hours, compared to the 1000-hour interval specified for the 1255.
  • The 1455 (1978-1981) and the 1455 XL (1981-1985) differ in both capacity and change interval. The base 1455 holds 31 liters with a 1000-hour change interval, while the XL version holds 33 liters and extends the interval to 1200 hours.
  • The 956 and 956 XL (1982-1985) list a standard capacity of 24.4 liters, rising to 28.6 liters when air conditioning is installed. The 4.2-liter difference reflects the additional coolant volume required to serve the air conditioning system's heat exchange components integrated into the cooling circuit.
  • The 955 (1978-1981) holds 23.8 liters, the smallest capacity among the non-856 models in the range. The 956 and 956 XL that followed in 1982 increased to 24.4 liters as the base figure.
  • The 856 XL and 856 XLA (1984-1985) carry the lowest cooling system capacity across all listed configurations at 21 liters, consistent with a smaller engine displacement relative to the 955, 1055, 1255, and 1455 series.
  • A 50-hour check interval applies uniformly across all listed configurations regardless of model, year range, or capacity. At this interval, coolant level and condition are assessed without a full drain, serving as a routine inspection point between full changes.
  • The 1000-hour change interval appears only on the 1255 (1978-1981) and the 1455 (1978-1981), both early-generation models. All other configurations in the range carry a 1200-hour change interval, representing a 200-hour extension in service life between full coolant replacements.

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