The leaks coming from somewhere else ..perhaps build up of oil inside the boost pipes ..leaking out of the boost pipe joints. sort of normal for this to happen, the boost pipes and the intercooler need cleaning out occasionally.
The actuator is simple in design, the red bit is a rubber diaphragm and the green bit a spring, arrows indicate pressure from the tube bit at the bottom. when it fails, its usually the rubber perished in the diaphragm.
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all the best.mark