A lawn mower works on an undulating surface too. Therefore if your tire has gone flat where not all the tires are on a level surface, do not try to change a flat tire at that place. Depending upon where the tire has gone flat, you can change the following procedure slightly, but ensure that the spirit of safety precautions is not violated.
If you have a portable air compressor with you, (even a foot operated one will do), try to inflate the tires and then shift your lawn tractor to a flat and level surface, it will be best for the tractor. If you do not have an air compressor and the flat area is nearby, take your tractor in, as is condition, to the flat surface. The lawn mower tires are a rugged lot. The tire will take this punishment without a murmur.
The procedure for changing the tire is as follows.
* You have already brought the tractor on a flat and level surface. Park it there. Shut off the engine. Pull the hand brake and remove the tractor keys in order to prevent accidental re-starting.
* Clean the tire to be replaced and the area around the tire with water. This will take away any dirt from the nuts holding the tires and reduce the work load on you while taking out the tire.
* Loosen the nuts holding the tire slightly. Make it a point to ensure that all the nuts are loosened slightly. Any one remaining to be loosened might give you a problem later on. Do not back off completely. Just loosen them and that is all. If you are not in a position to back off even a single nut, do not proceed further. Retighten the loosened nuts and ask for professional help.
* Fix up other wheels with a wheel lock or slip a wooden plank or a stone so that the wheel may not move. Do this to two wheels at least.
* Next slip a hydraulic jack or a crew jack at a convenient place on the chassis, (This place is usually indicated in the maintenance manual) and raise the wheel to be replaced).
* Back off all the nuts holding the wheel and take out the wheel. You may require some help in this as the lawn wheels are slightly larger than car wheels.
* After taking out the wheel, clean the brake drum (if you have one) and wash off all the dirt that has collected, remove anything lodged in there.
* Put a new wheel and get the other one repaired.
* Wear hand gloves all the time. This will prevent injuries to your hand.
* When loosening the nuts, give particular attention to slippage of spanners. They can cause serious injuries to hand or head as you will not be able to control your movement when spanner slips.
* NEVER EVER change a tire on an undulating surface. There are many cases when the jacks have slipped from their position due to this and deaths have resulted from persons being crushed beneath lawn mower.
Firestone Commercial Tires for Trucks