mehran doesn't have assisted brakes, the servo you're talking about is a vacuum based booster that helps you apply force to the master cylinder without effort.
Mehran doesn't have that booster and hence you use your power to brake. You can get a servo / brake booster installed in mehran without any major mods for under 4000 pkr.
'the pedals get hard' on vehicles with servo / brake boosters, since mehran doesn't have one you don't feel a difference.
And mehran uses brake fluid to maintain hydraulic pressure just like any other car, its just that mehrans don't have brake servos.