Radiator
The radiator is tubular-lamellar, with a safety valve built into the filler plug.
Safety valve opening pressure, kg/cm2:
- with increasing pressure: 1+0.15-0.10.
- with decreasing pressure: up to 1.0.
The passage of liquid through the radiator at a pressure of 0.5 kg / cm2, l / h: 20.
Test pressure, kg/cm2: 1.5.
Thermostat
Brand:
- «518», «520», «520i»: Wahler;
- «525», «528»: Behr.
Main valve opening temperature,°С: 80±1.5 («525» And «528»: 84).
Piston stroke of the main valve, mm: 8±1.
From model year 1978 on BMW «518», «525», «528i» with automatic transmission, «520», as well as on «520i» as of model year 1982, the start temperature of the main valve is 80°C. By BMW «518», «525» And «528i» with a manual transmission, it is 84°C.
Fan
Brand of viscous coupling («525», «528»): Fichtel und Sachs (Holset from model year 1978).
Fan drive belt brand:
- «518», «520»: Venfiflex 1106;
- «520i»: Vcntiflex 1112;
- «525», «528»: Aatbeit 2212 DA.
Water pump
The water pump is of centrifugal type.
Gap between pump casing and impeller, mm: 1±0.2 (on «525» And «528»: 0,9±0,2).
From model year 1980 Gap between impeller and pump housing for BMW «518» equal to 0.4-1.2 mm, for «525», «528i», «535i» - 0.7-1.1 mm.
From model year 1982 on BMW «518/E28» it is 0.8-1.2 mm, and for BMW «520» And «520i» with a six-cylinder engine - 0.4-0.8 mm.
Coolant
Capacity of interior cooling and heating systems, l:
- «518», «520», «520i»: 7,2;
- «525», «528», «528i», «535i», «520» And «520i» with a six-cylinder engine: 12.0.
Coolant used: mixture of distilled water and antifreeze (at temperatures up to -25°С).
Replacement interval: every two years of operation.