Brentford remain eight points from safety after an uninspiring draw which saw Neil Shipperley make his debut.
Michael Leary and Charlie Ide both had early chances for Brentford before Kevin Gall was denied at the other end by a great Nathan Abbey save.
Abbey tipped Paul Murray's effort from point-blank range around the post after the break before Shipperley's afternoon ended early when he picked up a knock.
Brentford squandered a flurry of late chances as Carlisle held on for a draw.
Brentford: Abbey, Frampton, Tillen, Osborne, Griffiths, Leary, Keith (Brooker 78), Mousinho, Kuffour, Ide, Shipperley (Willock 83).
Subs Not Used: Masters, Pinault, Charles.
Booked: Leary, Kuffour, Frampton.
Carlisle: Westwood, Raven, Aranalde, Livesey, Murray (Garner 76), Lumsdon (McDermott 19), Murphy, Thirlwell, Jeff Smith (Holmes 90), Hawley, Gall.
Subs Not Used: Williams, Gray.
Booked: Raven, Aranalde.
Ref: R Lee (Essex).