it cannot be repaired because firstly its not repairable, secondly if the front seal is leaking the seals cannot be found in Pakistan, and if you did get them from outside Pakistan you need proper tools to seat the seal on the shaft or you will rip the seal. So best get another item.
For overheating in city, you need to ensure that your cooling system is 100% working, no rust,no blocked fins. no direct fan, correct fan on the radiator and fan shroud sealed against radiator. The condenser fan needs to be good and working and condenser needs to have clean fins. After all this ensure that you use a good and original expansion valve. Not a cheap copy. For condenser fan use a SPAL branded fan that you can find very easily used - they are imported as scrap and they are broken up to extract their copper and other metals.