When replacing your riding mower tire tube, it is a good idea to check the tire and all of its component parts for wear and tear. Riding mowers equipped with tire tubes are more resistant to flats than riding mowers with tubeless tires. But not if they are damaged in any way. While you have the tube and tire off of the rim, examine the rim, tire and tube for any signs of excessive wear, rust or other flaws.
Stabilize the riding mower. Park it on a level, concrete surface. Engage the parking brake, turn off the engine and remove the key.
Raise the riding mower with a jack. Place the jack near the tire that you wish to change. Make sure that the top of the jack makes secure contact with the bottom of the mower's frame. Then lift the tire a few inches off the ground.
Release the air from the tire. Unscrew the valve cap (if present). Then press your flat head screwdriver against the side of the valve until all the air is released.
Detach the rim from the axle. For most models of riding mower, this can be done by pulling off the hub cap followed by a series of washers or removing a series of bolts. If you are unsure how to proceed, consult your riding mower owner's manual.
Break both beads of the tire. The bead of the tire is the inner edge that makes contact with the rim.Lay the rim flat on the ground. Then wedge your flat head screw driver between the lip of the rim and the bead. Then push down on the bead to un-stick it from the rim's edge. Work your way around the bead to pry it loose.
Lubricate both beads with tire lube to make them easier to remove and replace.
Pull the top bead of the tire over the rim. The best way to do this is to lay the rim flat on the ground. Then wedge your screwdriver underneath the bead of the tire (take care not to damage the bead or scratch the rim) and pop it over the rim section by section.
Pull out the tire tube by hand. Start by pulling out the valve stem of the tube then work your way around the tire until the tube is free.
Pull the bottom bead of the tire over the rim. This should be an easy enough job to do by hand (section by section) but enlist the help of the screwdriver again if necessary.
Examine the tire tube, tire and rim for damage. Then use a stiff brush to clean the rim before spraying it with the rust preventative.
Push the bottom bead of the tire down over the top lip of the rim. Again, use the screw driver to help you push the bead over the rim section by section if necessary.
Put in the new tire tube. First push the tire tubes valve through the valve stem. Then push the rest of the tire tube into the tire section by section around the rim. Take care to make sure that the tube does not twist or fold in on itself.
Re-attach the rim to the axle using the reverse of the procedure you used in step 4.
Fill the tire to the manufacturer-recommended psi rating.
Lower the riding mower and remove the jack.