Steering
Loose steering is usually caused by worn idler arms, our vans tend to eat them but at least they are very easy to replace. Most common power steering pump issues are leaks, snapped pump shaft, and noisy operation.
If you have a noisy pump, the first thing I recommend is properly bleeding the system of air and checking the condition of the fluid. Air in the system causes noise, false level readings, and pump damage over time.
99 and up they tell you to use a vacuum pump and adapter to bleed the power steering system.
Here is an adapter set that includes GM/Ford/Universal adapter https://amzn.to/3PtJdFo or you can get just the GM adapter https://amzn.to/3PEPnmx
Older bleed procedure was:
Turn the steering wheel fully to the left, fill reservoir to the FULL/COLD level. Leave the cap and engine off.
Turn the steering wheel fully to the left and fully to the right at least 20 times(at least 40 times with cooler or long hoses) with assistant watching fluid level/condition
Check the fluid constantly while turning the wheel, if bubbles recheck all connections then begin bleed procedure again.
Start and idle the engine, always maintaining the fluid level and reinstall the cap.
Center the wheels and lower vehicle to ground, let engine run 2min, turn steering wheel fully in both directions watching for:
Smooth noiseless power assist
Proper fluid level and condition
Absence of system leaks/bubbles/foam/fluid discoloration
Power Steering Fluid
It is important to flush your fluid of contamination regularly for the best performance and life of your power steering system.
It is important if you live in really cold climates to use a synthetic power steering fluid to avoid sluggish performance and leaks from hoses but I recommend using synthetic in all models.
Back in 94 GM put out a bulletin about reduced performance and touted a new Low Temperature Climate Service Fluid https://amzn.to/3Lg5Zhx, which is a semi-synthetic fluid recommended for 1980 and newer below 10°f esp with rack and pinion steering with long lines/coolers. Personally I would go with a quality fully synthetic these days.
Idler Arms
I recommend getting lifetime warranty locally if you do your own work, A/S vans tend to eat them regularly.
AWD (90-05) Both Sides Same Part
ACDELCO 45C1102 http://amzn.to/2opIEQu
MOOG K6392T http://amzn.to/2o4gSGP
RWD (90-05) Left w/ 12 mm Bolts
ACDELCO 45C1097 http://amzn.to/2nC7v4T
MOOG K6365T http://amzn.to/2oq8DYb
RWD (90-05) Right w/ 12 mm Bolts
ACDELCO 45C1098 http://amzn.to/2pqZ0pX
MOOG K6366T http://amzn.to/2o4dJ9V
Sway Bar Bushings
Grease-able, came in a few sizes, make sure to measure