A CRJ-200 FLT CREW PREFLIGHTING FOR A MAINTENANCE FERRY FOUND SEVERAL DISCREPANCIES INVOLVING THE APU AND A/C PACK PLUMBING.

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FLT CREW ARRIVED TO OPERATE FLT AS A MAINT FERRY. THE ACFT WAS POWERED DOWN UPON CREW ARR. AFTER POWERING UP THE ACFT AND APU; THE CREW PERFORMED A NORMAL PREFLT ALONG WITH ALL FIRST FLT OF THE DAY CHKS; WHICH WERE ALL NORMAL. THE ACFT WAS LEFT UNATTENDED WITH THE APU RUNNING FOR APPROX 15 MINS WHILE THE FERRY PERMIT WAS BEING CORRECTED AND WHILE THE CREW DISCUSSED THE GENERAL CONDITION OF THE ACFT WITH MAINT CTL. UPON RE-ENTERING THE FLT DECK; IT WAS NOTED THAT THERE WERE 2 NEW CAUTION MESSAGES DISPLAYED: APU BTL LOW AND HYD SYS 1 HIGH TEMP. A MECH WAS SUBSEQUENTLY CALLED OUT TO THE ACFT AND ALONG WITH THE FLT CREW THE DECISION WAS MADE TO SHUT THE ACFT DOWN AS THERE HAD OBVIOUSLY BEEN AN APU BOTTLE DISCHARGE AND; THEREFORE; THE APU WAS WITHOUT FIRE PROTECTION. THE MECH INSPECTED THE AFT EQUIP BAY TO FIND A METAL PIPE LOCATED BTWN THE L PACK AND HEAT EXCHANGER TO BE LOOSE AND VENTING BLEED AIR. HOT BLEED AIR FROM THIS LEAK HAD SET OFF THE APU FIRE BOTTLE AND HEATED THE #1 HYD SYS TO APPROX 99 DEGS C; WHICH IN TURN EXPANDED THE HYD FLUID TO MORE THAN 100% CAPACITY AND CAUSED A SMALL AMOUNT OF VENTING OF THE FLUID OVERBOARD. SEVERAL ATTEMPTS WERE MADE TO REINSTALL THIS PIPE BUT IT WOULD NOT FIT; INDICATING THAT IT MAY HAVE BEEN THE INCORRECT PART FOR THAT LOCATION. EVENTUALLY; IT WAS AGREED THAT THE ENTIRE L SIDE OF THE BLEED AIR SYS WOULD HAVE TO BE SHUT OFF FOR FLT; WHICH WAS ACCOMPLISHED BY STARTING THE ENGS WITH THE APU; SHUTTING DOWN THE APU; AND OPERATING ONLY THE R SIDE 10TH STAGE BLEED AIR AND THE R AIR CONDITIONING PACK. AFTER RE-FILING OF THE FLT PLAN AND A RECHK OF ALL PAPERWORK INVOLVED; THE ACFT WAS THEN FERRIED WITHOUT INCIDENT. THE ACFT HAD BEEN PLACED IN MAINT DUE TO A LIGHTNING STRIKE. IT IS POSSIBLE THAT THIS DAMAGE COULD HAVE BEEN A DIRECT RESULT OF THAT STRIKE; OR IT MAY HAVE OCCURRED DUE TO HUMAN ERROR AND INCORRECT INSTALLATION OF THE PART. HAD THE EVENT OCCURRED IN THE AIR; SIGNIFICANT DAMAGE MAY HAVE OCCURRED. A THOROUGH PREFLT AND THE EICAS SYS PREVENTED THE ACFT FROM EVER BEING IN DANGER. THE CURRENT ACFT LOGBOOK HAD NO RECORD OF WORK PERFORMED ON THIS PART THAT FAILED; BUT IT IS POSSIBLE THAT IT WAS INCORRECTLY INSTALLED BEFOREHAND. IT IS ALSO POSSIBLE THAT THE LIGHTNING STRIKE THE ACFT SUSTAINED CAUSED THIS DAMAGE. IF IT IS BECAUSE OF IMPROPER INSTALLATION; THEN A MORE THOROUGH INVESTIGATION OF MAINT WORK PERFORMED ON THE ACFT WOULD HAVE PREVENTED THIS SITUATION.