a hydraulic device receiving discharged oil from {HEAD ~ said pump} to assist {TAIL ~ a steering wheel} by hydraulic power 
to assist
a hydraulic device receiving discharged oil from { HEAD ~ said pump } to assist { TAIL ~ a steering wheel } by hydraulic power
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH