Changing a Tractor Tire Valve Stem
Lessons Learned from a Broken Tire Valve Stem
A broken tractor tire valve stem can put a damper on your day. We use our tractors in some pretty rough terrain, but I’ve found that dealing with brush and felled trees is my danger zone. Things get bent, broken, stabbed, and wrapped up when I’m in a mess of brush, which leaves me with some inconvenient breakdowns.
Tractor Tire Valve Stem
Most modern small farm tractors have tractor tire valve stems that include a metal body. You might think this makes them sturdy and resilient, but they’re not. Being a thin metal part, one well-placed piece of wood is all it takes to shear the stem off, whereas a rubber stem may give, bend, and return to position.
Flat Tire Fun
It’s never fun to have a flat tire on anything, let alone your tractor. What’s more, it seems that you’re almost guaranteed that you’ll get a flat tractor tire in the worst of spots and the worst of times. Be it mud, snow, or brush; it’ll be a challenge to your temperament and ingenuity at best.
Lifting a Tractor
If you have a bucket loader and a flat front tire, then you’re in luck! Using the edge of your bucket, it’s pretty easy to lift the entire front end of your tractor off the ground and out of whatever mess you’re mired in. Hydraulics do fade, and bucket loaders will leak, so be sure you put something under the tractor to act as a jack stand of sorts for safety. If you have a flat rear tire and you don’t have a backhoe attachment on at the time, then you may need to get creative with other farm implements or get a good old bottle jack. If all else fails, you may be able to avoid lifting your tractor completely.
Where is the stem? Your tire is likely already partially popped off the rim, so rotate your tire either by driving on it, or spinning it if you manage to lift the tractor. Usually, the best position for the stem will be at the 3 o’clock position or the 9 o’clock position, but the environment may dictate the orientation for you. In either case, get the wheel turned so that you can access both the inside and outside of the stem hole at the same time.
Most OEM tractor tire valve stems include a nut on the outside of the rim. Because of the design of these stems, we need to remove this outer nut so we can knock the rest of the stem inward to remove it. For the sake of sanity, a cordless impact tool with an appropriately sized socket will do the trick, but if you don’t have one, you’ll likely need help.
I found that when trying to remove a stem with a ratchet wrench, the stem spins in the wheel. Be prepared to have someone hold the inside portion of the broken tractor tire valve stem with a set of vice grips or long reach pliers. Avoid dropping the broken stem in the tire; you don’t want to go fishing for it later. If you do have an impact wrench, I found that using a length of coat hanger wire to catch the remainder of the stem works out well. Just poke the end of the wire into the hole in the middle of the stem on the inside, unbolt the nut, and the stem should slide down the wire and into your hand.
Picking a Stem
For those of us using an off-the-shelf generic rubber stem, be sure you get the correct size stem for the hole in your wheel. Bring the old stem with you to the parts store, or measure before you go. Most valve stems are one of two standard hole sizes and any big box store with an automotive section or tractor equipment section should have them both. If you’re not sure which size it is, buy both and hold on to the other stem for another tire.
Thankfully, there are tools for pulling a tractor tire valve stem into a wheel. Stem puller tools come in various shapes and sizes, but the most common and cheapest tool is a simple steel cable with a fitting on one end to thread onto the stem and a handle on the other. If you thought ahead and bought a spare OEM tractor tire stem, then you may not need a pulling tool, just a wrench and socket. You may additionally need a spoonbill tire tool, a piece of steel rod, or a long breaker bar to manipulate the tire to gain access to the inside of the rim.
Changing a Tractor Tire Valve Stem
For a pull-through rubber tractor tire valve stem, feed the pulling tool into the wheel from the outside. Remove the threaded cap from your new stem and thread it onto the puller dangling inside the tire. Make sure the neck of the stem finds the hole in the rim and pull the stem out by the handle of the puller tool.
Pull until the tractor tire valve stem seats in the rim. If it’s too tight to pull, wrap the stem tool’s cable around the handle of a socket breaker bar and use it as a leverage multiplier. It should seat with a little tug. If you’re having a hard time pulling the stem through, try some dish detergent on the stem. Never use grease, WD-40, PB Blaster, or anything that may be deleterious to rubber. Those products may eat your valve stem over time.
Now that you’ve managed to install your stem, you have the challenge of airing a tire up with a broken bead. The “bead” is the edges of the tire that seal against the rim. First, use dish detergent or soapy water to slick up the beads of the tire and edges of the rim. If you were able to lift your tractor, put a ratchet strap around your tire and tighten it. This will compress the tire and help you get a seal. If you didn’t lift the tractor, you might have to roll a little on your flat tire to get a ratchet strap around your tire.
Once you have a ratchet strap in place, you may need to strike your tire with a mallet or dead blow hammer to finish seating the bead. Keep hitting the tire as you fill it with air to completely seal the bead. Once the tire holds air, spray the beads with soapy water and check for air bubbles. Strike the tire in the areas that show bubbles until they stop, which indicates that the bead sealed fully against the wheel.
Avoiding the Scenario
If you’re tired of flat tires and broken tractor tire valve stems, consider using tractor tire fluid, especially foam loading. Foam loading will turn your tire into solid foam core tire, which is difficult to replace once worn, but will never go flat on you.
Have you had to change a valve stem creatively? Let us know what challenges you overcame in the comments section below!