power steering pump 89 cherokee

[irishsetter48]

I have an 1989 cherokee laredo 4.0. While driving the jeep the power steering seemed to not work well. Real hard turning. I purchased a working pump on ebay and filled it with new fluid, and I still have some hard turning. Most of the time the steering is smooth. Is there anything else I need to replace? (I did replace the serpentine belt, too). Or is some of the hard steering caused by the 235 tires? Thanks for your help.

[Bounty__Hunter]

Could be the steering box.

235's won't cause any steering issues, they're not much larger than stock.