I think them amal valves are more trouble than there worth ,i done away with mine , connect a pipe from the compresser housing to the actuater and cut it in half and connect a bleed valve to them, i did have it on a rolling road to set up boost and fuel but never had anymore proplems , yhe guy operating the rolling road said bleed valves are fine but dont be tempted to screew em up some more .
I think a rolling road check is sometimes the cheapest repair