It fails due to bent hps pipes, clogged hps pipes, or clogged or bent steering hps lines...
Iske ilawa it never fails away...
There must be any problem in it, maybe the person it is again n again claiming hps is bad, though hps is very rough n tough system... So kindly check for air leaks, like copper washer kay bagher if u tighten pipe of hps on pump it picks air from surrounding and behaves hard.. So kindly check what's the issue is... I have been doing swaps and maintenance of liana cars from quite long, but never ever heard that Suzuki liana's hps system has failed.
My friend had leak steering, he poured thick oil in hp pump even then pump was working not failing.