CRJ flight crew rushed on an early morning departure received an aircraft with hydraulic pump 1B deferred. The flight departed normally and has various other alerts in-flight; upon arrival it is noticed that there is in fact a burst hydraulic line not an inoperative pump as the deferral stated.

Narrative

Arrived at the aircraft very early in the morning having had an early wake-up. Noticed a Hydraulic Pump 1B deferred on the release. I went about my duties doing the preflight -- security check; getting ATIS; clearance; etc. Captain was very slow getting all of his duties done (he is a new transition from another fleet); so I also programmed the FMS after all of my other duties were done. We both looked at the MEL and the maintenance log and didn't find anything unusual about having a Hydraulic 1B Pump deferred other than the fact that it said it must be listed in the remarks of the release. When looking at the Hydraulic Synoptic Page; noticed dashes across the quantity indicator and also 0 PSI in manifold. The 0 PSI did not bother me because the engine was not running; but I was unsure about the dashes across the quantity. The Captain and I talked about this briefly and both decided that this was because the B pump was deferred. (I assumed that the dashes and also the 0 PSI would go away once we had the engine running.) We started both engines and had a short taxi to the runway. I never checked the hydraulic synoptic page due to the short taxi. I was pilot flying so I did the takeoff and as we climbed through 800 FT; we received a flight spoiler deploy. The Captain bumped the flight spoiler lever and the message went away. We also noticed that we had GLD fault and Flight Spoiler status messages. We checked the Flight Control page and also the Hydraulic Synoptic Page and noticed that we still had the same indications on the Hydraulic Synoptic Page. We also noticed that on the Hydraulic Synoptic Page under the manifold where all the controls are listed; that the 'outboard GLD' was yellow. Captain and I discussed this and decided that it must be a false indication and that we could continue. Captain was also convinced that the GLD was normal because the MEL has a line that says it must be a false indication and that we could continue. Captain was also convinced that the GLD was normal because the MEL has a line that says it must be listed in the release. We never received a Hydraulic System 1 Low Pressure message; so we knew there was pressure in the system. Landing; we received an Outboard Ground Spoiler caution message and noticed that the outboard section of the ground spoilers did not deploy. (All other GLD deployed and we received a green GLD Deploy advisory message on EICAS.) Taxied in to the gate and called maintenance. Maintenance arrived at the plane and after looking at the plane told us that the hydraulic system 1 reservoir was empty. They attempted to refill the reservoir and had us motor the engine. It was then that they discovered that a hydraulic line was burst in the nacelle and that was where the hydraulic fluid was pooling up. (This is why a leak wasn't apparent on the preflight). Maintenance towed the plane to the hangar and we continued the last day of our trip with a different plane. Noticed that we had a problem in the air on the way back. But did not know how serious it was until we talked with maintenance at the gate due to the fact that we never received a Hydraulic 1 Low Pressure caution message. Several things contributed to us not realizing that this was a problem. The Captain was new to the airplane and was not feeling 100%. It was early in the morning with a lot to do and a short amount of time. The MEL stated that a remark must be listed in the release; but no explanation was given as to why this should be in the release. (Still don't know why this would affect takeoff or landing; but I think it was because it listed a minimum landing weight of 38;500 LBS.) I believe from looking at the write-up in the discrepancy log that a pilot wrote this up at an outstation and it was deferred by maintenance over the phone. I don't know if they had the same indications that we did; but it was probably improperly written up as a Hydraulic Pump 1B when in fact the whole system was leaking and the 1B pump wasn't working properly because it didn't have any hydraulic fluid to pump! The aircraft was flown to our outstation meaning it flew at least 2 legs by the time it got to us and 1 more back before we realized it was a problem. Too many times on this plane it is simply a faulty indication (i.e.; flight spoiler status messages or computer monitor) and I think that we learn to not fully trust some of the EICAS messages. I assumed it was just a faulty indication or that the hydraulic page was supposed to look like that with a B pump deferred. Had the MEL said something like 'verify hydraulic quantity and pressure;' we might have figured it out. MEL should be less ambiguous. It should state why there are remarks in the release. Flight Attendant arrived for the trip getting over a cold. Captain got sick on day 2 and I am sitting here typing this now with a cold. The Flight Attendants are afraid to call out sick because of the fact that they might get an occurrence. I think that when maintenance gives a deferral over the phone at an outstation; they should question it a bit more. This plane flew 2 legs with 2 different crews before it got to us. We shouldn't have let ourselves get rushed in the morning and questioned the hydraulic indications. A simple call to maintenance that morning could have answered our questions. Not sure if calling enroute would have made a difference but this was an extra tool that could have been used as well.