You need to check for fluid, leaks, and so on. The system is fairly simple. if you have a belt turning the pump, correct fluid level in the reservoir and no leaks, it should work. If not, the pump or valve in the pump is usually the problem. Some pumps also have a screen/filter that cloggs up and could be an issue. This is on a system with a steering box. If it has a rack & pinion the problem could be in the rack.
Search Wiki for 1998 Chevy Suburban power steering pump replacement, the author based his answer on a 1997. Enjoy
http://www.gmtruckclub.com/forum/showthread.php?t=10354
The 1998 Chevrolet K2500 Suburban is able to tow up to 6,000 pounds. Standard features include power steering, and tinted glass.
You don't, you take it to the dealer if you have a problem with it. That car has a recall because it has had a lot of previous problems. The power steering is bad.
Begin by removing the belt from your 1994 Chevy Suburban power steering pump. Remove the power steering pump hose. Remove the power steering pump retaining bolts. The power steering pump will come off.
power steering fluid
The power steering pump. Autozone will probably do it for you if you ask.
The 2012 Chevrolet Suburban is 6 ft. 7.1 in. (79.1 in.)1 one-touch power windows wide.
The 2004 Chevrolet Suburban is 6 ft. 6.9 in. (78.9 in.)1 one-touch power windows wide.
The 2007 Chevrolet Suburban is 6 ft. 7.1 in. (79.1 in.)1 one-touch power windows wide.
The 2005 Chevrolet Suburban is 6 ft. 6.9 in. (78.9 in.)1 one-touch power windows wide.
The 2010 Chevrolet Suburban is 6 ft. 7.1 in. (79.1 in.)1 one-touch power windows wide.