Narrative:

During a july morning 2014; we started the right engine on a cessna ce-750 aircraft. After starting the right engine; we performed a power takeoff unit (ptu) hydraulic transfer check. We noticed that the 'a' hydraulic system pressure would not show 'green'. The hydraulic system was cycling as it should and by deploying the speed brakes we activated the ptu. The ptu was cycling from 1;500 psi - (2500-2700); but would never show a 'green' indication. We thought this was odd and confirmed that the 'a' system would pressurize using the 'a' auxiliary ( aux) pump; which it did. Shutting off the 'a' aux hydraulic pump again let the system bleed down and the ptu took control again; but only produced 'amber' indications. We decided to call maintenance and he seemed a little puzzled also as to why. After captain X and maintenance exchanged a little troubleshooting and information sharing; maintenance decided it should be escalated to a technical group. Technical concluded that the ptu was not providing enough power to the 'a' hydraulic system of at least 2;800 psi and that was why it was not working properly and showing 'amber'. We then conferenced company maintenance back on the phone and he had different numbers from the technical group and said that we were fine; but could not give us a reason as to why the hydraulic indications were 'amber'. This whole conversion was with captain; but as soon as we questioned why 'amber' indications were present; the conversation went south very quickly. I have to say that the captain did a good job of standing his ground. Maintenance started yelling and honestly acting in a way I have never heard before. The lack of answers and conflict of limitations from two sources was very disconcerting. I am not a rocket scientist; I know that. However; if the ptu function is supposed to charge the system to a 'green' indication; then it should. Airline transport pilot. Contracted maintenance. Repositioning flight. Flight cancelled.

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Original NASA ASRS Text

Title: A pilot and a Maintenance Controller describe different perspectives on whether or not a Power Transfer Unit (PTU) on a Cessna CE-750 aircraft was providing enough hydraulic power. Hydraulic pressure from PTU would not move beyond the 'Amber' indication range.

Narrative: During a July morning 2014; we started the right engine on a Cessna CE-750 aircraft. After starting the Right engine; we performed a Power Takeoff Unit (PTU) Hydraulic Transfer Check. We noticed that the 'A' Hydraulic System pressure would not show 'Green'. The Hydraulic System was cycling as it should and by deploying the speed brakes we activated the PTU. The PTU was cycling from 1;500 PSI - (2500-2700); but would never show a 'Green' indication. We thought this was odd and confirmed that the 'A' System would pressurize using the 'A' Auxiliary ( Aux) Pump; which it did. Shutting off the 'A' Aux Hydraulic Pump again let the system bleed down and the PTU took control again; but only produced 'Amber' indications. We decided to call Maintenance and he seemed a little puzzled also as to why. After Captain X and Maintenance exchanged a little troubleshooting and information sharing; Maintenance decided it should be escalated to a Technical Group. Technical concluded that the PTU was not providing enough power to the 'A' Hydraulic System of at least 2;800 PSI and that was why it was not working properly and showing 'Amber'. We then conferenced company Maintenance back on the phone and he had different numbers from the Technical Group and said that we were fine; but could not give us a reason as to why the hydraulic indications were 'Amber'. This whole conversion was with Captain; but as soon as we questioned why 'Amber' indications were present; the conversation went south very quickly. I have to say that the Captain did a good job of standing his ground. Maintenance started yelling and honestly acting in a way I have never heard before. The lack of answers and conflict of limitations from two sources was very disconcerting. I am not a rocket scientist; I know that. However; if the PTU function is supposed to charge the system to a 'Green' indication; then it should. Airline Transport Pilot. Contracted Maintenance. Repositioning flight. Flight cancelled.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.