Loose steering after hitting bump., I loose steering for a few seconds after hitting a bump. Options

[rapid36]

Hey guys i have a 94 Celica ST. The car was sitting for 4 years due to needing a new engine. i finally put one in it and when turning the wheel all the way to one side it squeals and stops the belts, so i looked inside the power steering pump and there was a lot of gunk at the bottom so i took it out and cleaned everything really nice and put it back in, after putting it back in the squeal went away and the belts were perfectly fine. however when i drive down the street and hit the slightest bump even the little reflector bumps in the middle of the lanes i would loose steering for 2 seconds and then it comes back, its not bump steer because it doesn't move my tires. my steering wheel gets loose and wont move the tires until 2 seconds later. ima crawl under the celica today but when im down there is there anything inperticular that i should look out for?