Cooling System - Bleeding Procedure
90subaru03NUMBER 02-75-90
DATE 09-11-90
APPLICABILITY ALL LEGACY MODELS EXCEPT SPORT SEDAN
SUBJECT: BLEEDING AIR FROM THE LEGACY COOLING SYSTEM
When refilling the cooling system it is necessary to bleed all the air from the system, or severe engine damage could result.
This method is an alternative to the procedure shown in the Legacy Service Manual Section 1-5 [05A1] Page 11. Either method may be used.
1. Before refilling the system, ensure that the drain is closed and the two (2) engine drain plugs are installed and all hoses are secure.
2. Remove the radiator cap, radiator vent plug, reserve tank cap, and separate the upper radiator hose from the radiator.
3. Pour prepared coolant in the upper radiator hose on the engine side until the hose is full.
4. Reinstall the hose to the radiator and tighten clamp.
5. Slowly pour prepared coolant through the radiator filler neck until the level reaches the filler neck.
NOTE: If the coolant level slowly drops, keep adding coolant until the level remains topped off.
6. Fill reserve tank to the full mark.
7. Reinstall vent plug and reserve tank cap.
B. Check system integrity by installing a coolant pressure tester to ensure that the system is sealed. Remove tester and install radiator cap.
9. Run engine until full operating temperature is reached (180~F).
10. Stop engine, let it cool dovn to room temperature, then carefully check the coolant level in the radiator and the reserve tank and add if necessary.
CAUTION: Take preventive measures to protect eyes and uncovered skin against burning when the coolant system is at full operating temperature and under pressure.