If you are talking about the vacuum actuator, check to see if there may be a small crack, tear, or hole in the black diaphragm. That will keep it from operating and opening or closing the fluid control valve. The actuator is easily removed and you can test it by blowing into the tubes where the vacuum lines connect to it.

__________________
Gary


1973 450SL
1999 Silverado 4X4 Ext Cab
1999 Mercury Sable
1972 450SL Parts car

Previously owned keepers:
1967 MGCGT - 3L-6
1972 Mustang Fastback - 351C

Current Cylinder Index: 37