The 31-year-old striker, on loan from Championship neighbours Huddersfield Town, played a key role in City’s third home league win, including scoring his third goal in seven matches.
Parkin said: “He has a terrific work ethic.
“He is winning headers, running into channels, he enjoys scoring goals and he has a tremendous amount of fitness and energy for someone of his age.
“He also has a good partnership going with Billy Clarke.”
Bradford dominated the first half and their pressure paid off three minutes before the interval with a goal by midfield player Billy Knott.
Winger Andy Halliday flicked the ball into the path of Stead and he played it across the face of goal for the unmarked Knott to tap into the empty net.
Orient equalised in the 75th minute when substitute David Mooney took advantage of a mistake by defender Rory McArdle.
But the visitors lost striker Chris Dagnall two minutes later, sent off for a foul on Knott, and Bradford took advantage with two goals in three minutes.
Clarke restored their lead in the 79th minute with a shot high into the net from James Meredith’s cross.
Stead then added a third in the 81st minute after closing down an attempted clearance from goalkeeper Adam Legzdins.
Bradford City: Pickford, Darby, McArdle, Davies, Meredith, Halliday (Zoko 80), Liddle, Knott, Yeates, Stead (Hanson 89), W Clarke. Unused substitutes: Williams, Sheehan, Kennedy, Routis, Mottley-Henry.
Leyton Orient: Legzdins, Omozusi, Cuthbert, N Clarke, Dossena, Pritchard (McNuff 45), Wright, Price, Cox, Dagnall, Plasmati (Mooney 65). Unused substitutes: Grainger, Sawyer, Baudry, Batt, Lee.
Referee: Darren Handley (Bolton).
Man of the match: Jon Stead.