Ford 1989 Bronco Owner's Manual page 140

Tires, Wheels and Loading
2. Remove the cap from the valve on one tire, then firmly press the tire
gauge onto the valve and measure the pressure with the tire gauge.
3. Add enough air to reach the recommended air pressure.
Note: If you overfill the tire, release air by pushing on the metal stem in
the center of the valve. Then recheck the pressure with your tire gauge.
4. Replace the valve cap.
5. Repeat this procedure for each tire, including the spare.
Note: Some spare tires operate at a higher inflation pressure than the
other tires. For T-type/mini-spare tires (see Dissimilar Spare
Tire/Wheel Information section for description): Store and maintain at
60 psi (4.15 bar). For full-size and dissimilar spare tires (see Dissimilar
Spare Tire/Wheel Information section for description): Store and
maintain at the higher of the front and rear inflation pressure as shown
on the Safety Compliance Certification Label or the Tire Label.
6. Visually inspect the tires to make sure there are no nails or other
objects embedded that could poke a hole in the tire and cause an air
leak.
7. Check the sidewalls to make sure there are no gouges, cuts or bulges.
140
2010 Econoline (eco)
Owners Guide, 3rd Printing
USA (fus)