Hei!  
Vet ikke helt åsen man gjør det, men i Haynes boka står det for såvidt noe, men det e jo alerede fortalt!  
If, after draining and refilling the system, symptoms of overheating are found which did not occur previously, then the fault is almost certainly due to trapped air at some point in the system, causing an air-lock and restricting the flow of coolant; usually, the air is trapped because the system was refilled too quickly. In some cases, air-locks can be released by tapping or squeezing the various hoses. If the problem persists, stop the engine and allow it to cool down completely, before unscrewing the expansion tank filler cap or disconnecting hoses to bleed out the trapped air. 
Tokk mæ ikke bry til og oversette.  :bok  
Men he ein kamerat som kjører Jeep, han hadde luft i systemet, han fikk beskjed om og finne den brateste bakken han kunne finne, stå i den og ruse motoren sån at han fikk god sirkulasjon, for så fylle på nyt.  m'm Skade ikke prøve!  ;)