B737-800
Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 138; Flight Crew Total 5300; Flight Crew Type 201
Distraction; Troubleshooting; Workload
Aircraft Equipment Problem Critical; Inflight Event / Encounter Unstabilized Approach
Flight Crew Overcame Equipment Problem; General Maintenance Action
Aircraft
I was First Officer (FO) on Aircraft X operating to ZZZ. We were conducting the ILS XXR circle to XY approach when we received an abnormal landing gear indication. When I lowered the landing gear; the annunciator panel showed 3 red lights along with 3 green lights. The overhead panel showed 3 green as well. We briefly discussed continuing the landing as there was some confidence the gear was down. The discussion continued until around 500 ft. and I felt strongly that we shouldn't be making such consequential decisions that close to the ground without running a checklist. We performed a go-around; ran the checklist; got the gear down without the red lights; and landed successfully.
ILS XXR circle XY at ZZZ. Lowered gear just prior to FAF (Final Approach Fix). 3 red; 3 green illuminated. After evaluating with First Officer (FO); executed go-around on XY due to gear disagree. Standard missed. Ran checklists. Vectored for longest runway... ILS XXR. Extended gear on 10-mile base. All indications normal. Executed normal landing. Taxi to gate to find puddle [of] hydraulic fluid at left main. Possibly unrelated.
B737 flight crew reported an issue with the landing gear indications.