Date: 202107
Local time of day: 1801-2400
Location: ZZZ.ARTCC, US
Light: Night
Aircraft: B737 MAX 8
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Cruise
Airspace: Class A ZZZ
Aircraft component: Hydraulic Main System
Component problem: Failed
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Not Flying
Reporter qualification: Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Human factors: Workload; Distraction; Troubleshooting; Situational Awareness; Time Pressure
Anomaly: Aircraft Equipment Problem Less Severe
Detector: Automation Aircraft Other Automation; Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Flight Crew Requested ATC Assistance / Clarification; Flight Crew FLC complied w / Automation / Advisory
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: During cruise flight; the Master Caution light illuminated with the #2 engine driven B hydraulic system light. We ran the QRH and turned the pump off; and also noted that the B system indicated approximately 3000 psi but zero quantity. We discussed the possibility that although technically the conditions were not yet met per the QRH; there was a strong possibility that entire B system had likely failed or was failing and notified Dispatch via ACARS that it was a possibility. We ran the weight data for landing in ZZZ with the B system inop; and came up with approximately 1;300 feet of stopping margin with max manual braking. We let Dispatch know that even with a hypothetical total loss of the B system; ZZZ was still acceptable and they concurred with our stopping margin calculation.  The B system held steady with approximately 3000 psi until we started our descent into ZZZ with approximately 120 miles to go.  As we were descending; the psi of the B system quickly dropped to near zero and the ELEC 1 B pump Low Pressure light illuminated; along with the Flight Control B Low Pressure light. We ran the QRH for Loss of System B and calculated brake cooling; which advised staying off the gate for 30 minutes.We advised Approach of the situation and asked for delay vectors for checklists and CFR (Crash Fire Rescue)  trucks to be present at the end of the runway to check brake temps and condition after landing. We landed on the runway at the end and shut down engines at the request of CFR. CFR noted that hydraulic fluid was leaking from number 2 engine and brake temps were above 500 C. They were also concerned about hydraulic fluid on the hot section of #2 engine aerosolizing and advised we wait for cooler temps for ramp safety. CFR advised that although the brakes had cooled acceptably they were still concerned about the possible aerosolizing of hydraulic fluid from #2 engine hot section and advised we wait another 10 minutes. This all led to a lengthy ground delay but we did the best we could to keep the flight attendants and Passengers informed. In our judgement it was the safest course of action to follow CFR recommendations.




Synopsis: Air Carrier Captain reported the in-flight loss of one hydraulic system. The pilot crew followed the QRH procedures and landed at their destination.