Citation V/Ultra/Encore (C560)
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy
General Maintenance Action; General Flight Cancelled / Delayed
Human Factors; Aircraft
During pre-flight; I noticed the sign off; for a hydraulics problem; referred to a brake line being tightened. Because the main hydraulics system and brake hydraulic systems are closed loop system and are not interconnected; I knew that this was an incorrect maintenance action. After contacting my chief pilot and [maintenance]; I recommended that they go back and determine if maintenance personnel actually completed the required maintenance checks. [Maintenance] called me back and told me that they were going to place the aircraft out service and have additional maintenance checks conducted. Apparently; the second maintenance checks found a hydraulic leak requiring multiple parts being replaced. It is apparent to me as a former mechanic that contract maintenance does not have the skill set to work on the numerous [company] types of aircraft. Their lack of familiarity could've caused an accident or incident in this case had the hydraulics completely failed. I recommend that [our company] utilize in-house maintenance whenever possible and when contract maintenance is utilized; an in-house [company] Quality Control supervisor must sign off the maintenance documentation.
Cessna CE-560 Captain reported the possibility of an incorrect maintenance action to repair a hydraulic problem.