lately when I start my suzuki esteem, after parking it for a while, the power steering becomes very heavy and has erratic power assist at slow speed, when I ease out of the parking slot. It squeeks as I turn thr steering wheel. But once I get going, the problem disappears.

It can't be a loose belt because I just had it tightened at Mang Mario's. There's enough fluid naman, but there's aways power steering fluid residue around the pump.

What could be causing this? And are power steering pumps repairable here?