To restart the cutting wheel, the operator slowly releases {HEAD ~ the pedal valve} which starts {TAIL ~ the wheel} rotating again 
To restart the cutting wheel , the operator slowly releases { HEAD ~ the pedal valve } which starts { TAIL ~ the wheel } rotating again
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH