Ps
 

did a quick search not much luck. SO driving along on Tuesday about 30 min into the drive I lose all powersteering. Pull over belts are good and fluid in pump. So I drive back to work loads of upper body work out as the car is a beast with no PS. The car sits for 6 hours looking forward to the drive home and another free work out and PS is working again. I am very happy but, after about 30 mins stops. I think there is a check valve in the pump that can go and is not replaceble. Could this give these symptoms?
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