Do's and Don'ts of tire changing!
Getting started
As you can see from the first picture, I needed to change a tire. This is another one of those things that you as an owner can legally do. But don't do it by yourself until you have done it under the eye of someone with lots of experience first. It is a simple job, not unlike changing a tire on your car, but with different tools and on a smaller wheel. There are some serious pitfalls to avoid.
You will need a jack capable of lifting the wheel off the ground and supporting the plane while you have the wheel off. Other than the normal tools required for any maintenance, you will need access to an air source capable of blowing up the tube quickly.
Take it off
It is always best to jack the airplane while on a flat, hard surface. The same applies to your car, but often, you don't have any choice. Normally, your plane is in a hangar or on a ramp for this procedure which implies a flat, hard surface.
I found that the small scissors jack for my minivan works just fine for this purpose. Note in the picture that the bottom of the axle is sitting in the notch in the jack, giving me less chance of slippage. Chock both the other wheels and align the jack fore-aft. Jack only enough to get the tire clear of the floor. Remove the wheel cover and pull the cotter pin from the wheel nut. This task is guaranteed to bark a knuckle, so don't worry about a little blood.
Next, remove the bolts holding the inside pad of the brake assembly. Now, remove the wheel nut and slide the wheel off the axle.
In the picture below, note the wheel cover with the wheel nut and cotter pin on it and the brake pad and bolts laying on the other side of the jack.
Disassemble
Remove the valve core from the valve stem and allow all the air to escape. You can't re-use it anyway.
To remove the old tire and tube, you must separate the wheel halves. You will need an open end wrench and a socket wrench with a short extension. The bolt heads should be on the side with the brake disk (assuming a main, not the nose wheel) and will not have enough room to get a socket over them. Remove the three nuts, pull the bolts and lay them aside, along with the brake disk.
Getting the tire off the halves is the hardest part of this. With a large common screwdriver, gently pry the tire bead loose from the rim all the way around on both sides. Then lay the wheel on the ground with a shop rag covering the bearings, and kick the tire with your heel. DO NOT USE YOUR KNEE! See Chapter 44 of the journal for what happens when you do. Work all the way around until the tire bead is well clear of the rim. Turn over and do the other side.
Finish pulling the halves out and throw the old tire and tube away. Now, you have the parts as shown here, two wheel halves and a brake disk. Take them along with the new tire and tube to the place where you have an adequate air supply.
Re-assemble
Take the new tire and dump a liberal amount of talcum powder (Baby powder will do) in it. This will allow the tube to be inserted and positioned more easily. Rotate and shake the tire until the entire inside is covered with the powder. Then put the tube in. Get it fully inside the tire with no bunching and the stem aligned with the red spot on the tire. Make sure the tube wants to stick out on the side with the spot. If not, remove the tube, flip it over and re-insert it.
Remove the valve core and blow it up, Make sure that it is evenly stuffed into the tire and the valve stem is correctly positioned then let all the air back out. Now, feeding the valve stem through the hole in the wheel half, push the wheel half onto/into the tire as far as possible. Turn it over and insert the other half as far as possible.
There is a shoulder on one wheel half and a lip on the other. (You can see them in this picture. the bottom half slips into the upper half.) These must be correctly mated before the bolt holes will align properly. When you have this done, replace the brake disk and drop all three bolts in through the brake disk. Put all the nuts on finger tight and recheck the alignment of the shoulder and lip (small hands will go through the bearing so you can feel for proper alignment). Pull the stem all the way through if it didn't come voluntarily. Carefully tighten the bolts without allowing the alignment to slip
Blow the tire up to around 50 PSI and check for good seating to the rim, all around and on both sides. Allow the air to escape and re-install the valve core. Now inflate to normal pressure and check the valve stem for leakage.
Put it back on
Re-packing the wheel bearings is a judgement call. How dirty is the grease? How long has it been since they were last re-greased? Did you get some stuff into them during this procedure? Repack if necessary.
Slide the wheel back onto the axle and put the nut on finger tight. Re-attach the brake shoe to the back side. Tighten the wheel nut until the wheel no longer spins freely. Then back it off to align the holes with the slots in the nut. Replace the cotter pin. Re-install the wheel cover and lower the plane. Remove the jack and clean up. Then go home and lick your wounds.
Quick tip: I make a small identifiable mark on the outside of the wheel cover over the valve stem. This allows me to remove the two screws by the mark and only loosen the third screw to rotate the cover enough to get to the stem when adding air.