B747-400 flight crew reported hydraulic system malfunction in cruise. Flight crew returned to departure airport.

Narrative

Crew arrived at the aircraft 1 hour prior to departure. Due to Maintenance actions; flight blocked out almost 3 hours after scheduled departure time of XA:00. Upon logbook review and Maintenance briefing it was noted on the previous 2 flights there was the same discrepancy of HYD OVHT SYS 4. Maintenance advised crew that the discrepancy had been taken care of along with other deferrals and the aircraft was signed off airworthy.During climb out from ZZZ crew received EICAS message DOOR ELEC MAIN. PM referenced the QRH as the other 2 pilots observed and the onboard mechanic was also advised. Checklist was completed and pressurization was normal and flight continued toward destination. Reaching cruise altitude the Observer seat pilot left the cockpit to start his rest. Approximately 1 hour into the flight at cruise altitude FL330 an EICAS message of HYD OVHT SYS 4 was received. QRH was accomplished and per the checklist Engine driven and Demand pumps 4 were turned off. It was noted that the SYS 4 temperature began to come down but was still high forcing the system 4 to remain depressurized. Captain gave flight controls to FO and initiated a SATCOM call with Dispatch and Maintenance Control. Maintenance Control requested the aircraft be brought back to ZZZ and Dispatcher and Captain agreed as this was the safest course of action due to loss of many systems and abnormal configurations and with the most resources to address the problem instead of continuing to original scheduled departure station of ZZZZ. The relief pilot on rest was called back to the flight deck and assisted with checklists.A reanalysis by Dispatched was received and new routing coordinated with ATC back to ZZZ. Maintenance requested fuel dumping and this was accomplished bringing the landing weight under MGLW. ATC was also advised due the maintenance status of the aircraft. The aircraft was configured early and landed on Runway XXR in ZZZ. Aircraft taxied to parking and did receive a BRAKE TEMP EICAS message. A post-flight inspection was completed finding no damage and appropriate logbook discrepancies were annotated.Cause: Unsure of cause of HYD OVHT SYS 4 EICAS message but this was the 3rd flight in a row with the same discrepancy.