The Lilywhites, who are struggling with injuries at first-team level, put out a relatively inexperienced side with only Dave Hibbert and Eric Skora really having performed at senior level this season.
It was United who forced the pace straight from the off when Brendan McGill, returning from a leg injury, shot straight at Chris Neal in the Preston goal after only two minutes.
In the 27th minute United had a good chance to take the lead through Glenn Murray. The rangy Maryport-born striker ghosted between two North End defenders but he could only drive his effort wide of the near-post.
The Cumbrians were well on top now and looking dangerous down the left-hand side through the pacey on-loan Alan O'Brien. On the half-hour mark the Newcastle youngster made another good run down the wing as he flew past Warren Beattie and Anthony Warriner but his ball in only resulted in a corner.
Five minutes later United nearly took the lead again but the move would only end in disappointment as Pete Ferris had to be substituted with Paul Gardiner coming on to take his place. As the youthful North End defence played statues Ferris stole in to take the ball and run in on goal. Neal came off his line quickly though to take the ball away from Ferris' feet and the young striker came off worse in the challenge as he ended up being forced to hobble off the pitch.
Little else happened of note in the first half and both sides went into the break level at 0-0 although that scoreline was to change very quickly as United took a well deserved lead three minutes into the second half.
Jamie McClen hit a free-kick into the Preston box and Simon Grand managed to steal a march on his oppostion centre-half Steven Cudworth to head firmly past Neal and put the Blues 1-0 up.
United almost went close shortly after the hour mark but substitute Gardiner was just unable to get his foot on the end of a Dan Dillon cross in from the right.
In the 65th minute coach Billy Barr was forced to make another change to the Carlisle line-up due to an injury. O'Brien went off with a tightening groin and was replaced by youth team forward Andy Hardman.
The Blues had been defending well all game but in the last 20 minutes the midfield started to drop back a bit too much as Preston pushed forward looking for an equaliser.
The home side were beginning to make their possession tell and went close to levelling the match after 71 minutes. Ashley Parillon moved up the pitch well and played a nice ball into Lilywhites striker Dave Hibbert. Ex-Port Vale frontman Hibbert failed to hold the ball up but it ran free to the onrushing Parillon who could only blaze his drive well over the bar.
Four minutes later North End full-back Beattie tried an effort from distance but Anthony Williams held it well to make his first real save of the afternoon.
The Lancashire outfit were really pushing forward now and they finally got their equaliser in the 78th minute. Skora hit a curling free-kick from the edge of the box which pinged off the side of the wall and away for a corner.
From the resultant flag-kick Iain Howard swung a lovely ball in which Hibbert rose well to meet. His firm header bounced off Danny Livesey's shoulder and looped over Williams in the Carlisle goal to put the Lilywhites back on level terms at 1-1.
The afternoon was to only get worse for the Blues five minutes before the final whistle when Glenn Murray received a straight red card for a very poor late and high challenge on Beattie.
Carlisle hung well on for the last five minutes as they made their experience in defence count, only allowing a couple of half-chances.
The first a long range effort from the marauding Parillon which was deflected away for a corner off Simon Grand and the second a good save by Williams from a low Hibbert drive.
A draw away to Preston is never a bad thing but United had more than enough chances to have the game dead and buried well before Preston's equaliser. To add to the disappointing scoreline Glenn Murray will have to serve a suspension for his off sending. It also remains to be seen how bad the injury to young Ferris is just when people were talking him about him being given a chance in the first team squad.
Preston line up :
Chris Neal, Warren Beattie, Richard Baker, Eric Skora, Steven Cudworth, Matthew Cropper, Anthony Warriner, Ashley Parrilon, Dave Hibbert, Ashley Stott, Iain Howard.
Substitutes :
Ben Hinchcliffe, Dylan Adams, Paul Kenworthy, Liam Moloney, Chris McGrail.
United line-up :
Anthony Williams, Paul Arnison, Lee Andrews, Simon Grand, Danny Livesey, Jamie McClen, Brendan McGill, Dan Dillon, Glenn Murray, Pete Ferris (Paul Gardiner 35), Alan O'Brien (Andy Hardman 65).
Un-used substitutes :
Dan Kirkup, James Earl and Adam Bradley.
Updated Reserve Team Table : Click here
Updated Reserve Team Results : Click here