powderpig
SILVER Star
In reading all the comments I come to the conculison that most are not doing it right. You must hold the fan until the fan takes off (because the viscous fluid lock up the hub) or the temp gauge starts to rise(thus indicating the fluid is not locking it up). The temp in the area between the hub and the radiator gets too warm and the bi-temp coil releases the fluid. So You really need a second person to watch the temp guage to see if it the engine goes into the over heat zone(onece the guage needles moves past the normal zone). I have only had a couple in the almost 5 years of 80 series work be totally locked up, no spin at all when cold. any how it is a great subject that seems to get discussed again in summer. good luck with your trucks, later robbie
