A share of the spoils keeps Carlisle in touch at the top as a game of two halves swung one way and then the other on a dramatic night at Brunton Park.
A long throw from Ellis had Raynes interested early in the game and his flick took Clohessy out of the equation. Ibehre twisted to help it on but Cisak was alert and he did well to drop low and gather it up.
United worked hard to keep the ball in midfield and their patient approach coaxed Orient out of their shell. Gilliead, Kennedy and Hope used the space but Ibehre was unlucky as his cross hit a leg and flew straight at Cisak.
Ellis and Joyce worked a quick move moments later but Wyke couldn't quite get enough on his header and it spooned off into the night sky.
Carlisle continued to look the better side and determination from Ibehre and Kennedy brought a rash challenge on the latter which earned a free kick right on the edge of the area. Newcastle United loanee Macaulay Gillesphey took charge and he brought the crowd to its feet with a wonderful strike which flew into the top corner.
The Cumbrians kept pushing forward and a lovely flick from Ibehre sent Wyke one-on-one with Cisak. A strong touch gave the keeper half a chance and he did well to get his hand to an attempted dink from the striker as he rushed out to close down the angles.
A Wyke header from a cushioned Raynes set-up was his last contribution as a collision with the post took the striker out of the action, and local lad Steven Rigg returned to the fray as a natural replacement.
Orient finally showed as an attacking force on the half hour when a corner delivery skimmed across the face of goal. Hunt sent it back in and Brisley was disappointed as he scuffed a poor volley straight at Gillespie.
United recovered their shape and purpose from Hope sent him at the heart of the defence. Ibehre pulled wide and called for it but his low cross flew right at Cisak as he tried to find the unmarked Steven Rigg.
The home side almost capped off an excellent half with another goal when Ibehre robbed possession wide on the right. He fed it to McQueen and Kennedy was an inch away as he glanced a dipping delivery just past the angle of post and bar.
A double substitution brougnt more in the way of attacking intent from the O's after the break and Simpson had to be stopped in his tracks by an Ellis tackle before he could pull the trigger.
It was a short-lived reprieve as the division's top scorer came again with a jinking run on the edge of the area. Goal number 23 of the season followed as he stroked a fierce shot under the dive of the keeper.
The visitors grew in confidence and they thought they’d grabbed the lead when Moore was left unmarked for a Nolan cross. His header was crisp but it whipped over the bar. Player-manager Nolan then had a go himself in the middle of a good spell but his shot was always on the rise.
Carlisle got going again with a neat move which put Hope out wide. He surprised everyone with an early cross but Rigg couldn't quite make up the ground and it bobbled harmlessly wide.
United kept working hard and Gillesphey sent a lovely cross over after excellent build up play with Hope. Ibehre jumped to meet it but it was just an inch too high.
The Orient response was a long ball forward which brought a half clearance that fell in front of Nolan. He tried to control his volley but it was another which sailed off into the stands.
Chances started to come at both ends and a deflected Kennedy cross left Ibehre with a difficult volley. He got something on it but it was easy to clear.
Carlisle were caught on the break moments after a wonderful McQueen pass found Rigg inside the box. He couldn't quite set himself and a huge clearance suddenly left Palmer with just the keeper to beat. He made no mistake with a precise finish on the run.
The hosts upped the tempo and balls into the box caused problems as Ibehre and Hope waited. A shot from Rigg was blocked as Asamoah and Ibehre battled but the blue shirts stayed forward and Gilliead split the defence with the cross of the night. Raynes pulled off his man and glanced an unstoppable header into the back of the net.
Gillespie had to save low as Orient almost grabbed it in time added on but it was just about a fair result as the whistle blew on a pulsating game.
United - Gillesphey (17), Raynes (84)
Orient - Simpson (50), Palmer (72)
Orient - Hunt (40)
Carlisle United - Gillespie, McQueen (Asamoah 75), Ellis, Raynes, Gillesphey, Gilliead, Kennedy, Joyce, Hope, Wyke (Rigg 25), Ibehre. Subs - Bacon, Hery, Brough, Archibald-Henville, Thompson.
Leyton Orient - Cisak, Clohessy (Palmer 46), Baudry, Payne (Moore 46), Atangana, Brisley, Binnom-Williams, Simpson, Jahraldo-Martin, Hunt, Nolan. Subs - Grainger, Shaw, Essam, Turgott, Pritchard.
Referee - Mr Nigel Miller
Attendance - 3,721 (179 away fans)