The PIA B777 brake assys are from Goodrich and have the special procedure to fill in the grease while refurbished/repacked in the shop.
Earlier it was blamed on the wrong type of grease used which was NYCO (European brand of grease usually for Airbus), after a couple incidents of brake fire, PIA started using the right type of grease Aeroshell 22 (American brand of grease meant for use on Boeings), but unfortunately that was not the problem. The actual facts are somewhat different than using the wrong and then right types of greases. One of the difference is the flash point of the two greases.
One relief flight took the passengers from Man. to YYZ . The aircraft AP-BGL is still in Man. They are working on it to get it airworthy.
I would like to add here one more thing, there are only 12 incidents of similar nature on B777s , out of which 6 were with PIA. Goodrich is the boeing approved manufacturer for B777s brake assemblies.
The result of a minor mistake cost PIA a fortune, Slide rafts, Engine fire extinguishers, brake assy, wheels, down-time of the aircraft, and top of everything unsatisfied customers.