How to Fix a Leaking Lawn Mower Tire Rim. Apply bead sealer to stop the rim leak, inflate and remount the tire.
This project is continued from How to Fix a Leaking Lawn Mower Tire Rim – Part 1.
Tire Bead Sealer
A generous amount of tire bead sealant is brushed along the tire bead as shown. Don’t worry about getting the bead sealant on the sidewall because it dries quickly to a non-tacky finish that blends with the tire. Notice the newspaper under the tire and can to catch any drips.

After painting the bead sealant on one side of the tire, flip the tire over and apply bead sealant to the other side.
Seat the Tire Bead against the Wheel Rim
The tire bead is reset (popped back out) to seat it against the wheel rim by blowing a large volume of compressed air into the tire with the blow gun. The rubber tip of the air blow gun is held against the valve stem (remember – the valve core was removed so there’s no obstruction) and compressed air blown into the tire. This worked almost instantly to pop the bead back out against the wheel rim.

An alternate method for resetting the bead (especially if you have large tire) is to set a ratchet strap
around the tire and draw it tight to squeeze the sidewalls and bead outward against the rim. Use the blow gun if you have one to reset the bead. If you don’t have a blow gun, reinsert the valve core and fill the tire with compressed air in the normal way. The tire bead will pop out against the rim.
The tire bead popped out nicely against the wheel rim:

Once the bead pops out, it will stay in place when the blow gun is removed and there’s no air pressure in the tire.

Install the Tire Schrader Valve Core
Insert the Schrader valve core back into the wheel valve stem. If your valve stem is damaged or dirty, you can buy replacements at the auto parts store for a couple of dollars.

Screw the valve core into the valve stem with the valve core removal tool:

Inflate the Lawn Mower Tire
Inflate the tire with the tire chuck and air compressor. The recommended air pressure is stated on the tire sidewall. This tire should be inflated to 44 psi (Pounds per Square Inch).

Check the tire pressure with the pressure gauge. The end of the gauge extends to the pressure reading. The pencil tire gauge is showing 42 psi.

Reinstall the Wheel on the Lawn Mower
Mounting the wheel back on the lawn mower caster frame is straightforward. With the lawn mower still on jacks, do the following:
- Insert the axle bushing in the wheel hub.
- Hold the tire up to the caster frame so the center is aligned with the mounting holes in the caster.
- Insert the axle bolt through the frame and wheel.
- Screw on the axle nut.
- Tighten the axle nut with the two socket wrenches.

The axle bushing should be greased to replace any grease that was lost or wiped off when the bushing was removed. The bearing should also be greased for routine maintenance according to the lawn mower manufacturer’s maintenance schedule.
To grease the axle bushing:
- Check the Zerk grease fitting is clean and in good condition.
- Pump the grease gun until grease is flowing.
- Press the grease gun coupler onto the Zerk grease fitting. Check the fitting is secure.
- Give the bushing 3 or 4 squirts of grease.
- To remove the grease gun, angle the coupler off to the side and pull firmly.

Sealing the tire bead definitely fixed the problem and the mower tires have held steady ever since. Before I was having to add air every two weeks.
Take care,
Bob Jackson