To find it, you'll need to:
1. Locate the transmission: This is the large, usually cast-iron or aluminum box behind the engine.
2. Look for a small hose or tube: The breather is often a small tube or hose connected to a small, vented cap or fitting on the transmission case. This hose might lead to a higher point in the engine compartment.
3. Check the top and sides carefully: The breather isn't always easily visible and might be tucked away under some other components.
If you can't easily locate it visually, you might consider consulting a repair manual specific to your 1998 S10's transmission type (e.g., a 4L60E automatic or a manual transmission). A repair manual will provide diagrams and precise locations. You can find these manuals online or at auto parts stores.