Things looked bleak for Brush when Orient fell behind after 33 minutes when the giant Ben Burgess headed home Stuart Green's cross from the right.
However Orient responded and on the stroke of half time David Hunt fired a 20-yard free-kick into the roof of the net to earn his side a precious point.
Orient could easily have gone on to win the game as they piled on the pressure in the second half but could not find a way through the Tigers rearguard.
Brush admitted afterwards: "I think we showed we could battle and scrap and play as well.
"Hull are the best side in this division and we had them on the back foot in the second half. They were pleased to hear the final whistle." While Hull boss Peter Taylor said: "I have no complaints about the result. I thought we deserved to be ahead at half time but I was disappointed with our performance after that - Orient were the better team in the second half." Orient belied the lowly league position and should have scored early on when ex-Hull striker Gary Alexander fired wildly over.
The O's were hit with a sucker punch from Burgess but refused to buckle and the impressive Marcus Ebdon saw a volley tipped over by Hull keeper Michels Kuipers before Hunt's leveller.
In the second half Lee Thorpe went close for the home side but Hull were always dangerous on the break and Stuart Elliott almost restored their lead.
But in a grandstand finish Orient had the clearer chances as Mark Peters, Alexander, Tom Newey and Thorpe all went close to winning the game.