Looking for advice on proper pressure in rear tires, Goodyears. The cap on the valve stem seemed frozen on. When I used a vise grip to loosen it air started to escape. Might they be defective? Do you have a best method/proper care for inflation?
The rear tire pressure should be around 12 lbs. That may sound strange if you are not familiar with rear tractor tires but the pressures are nearly always low. As for the cap on the valve stem being frozen on, I suspect it is rusted on. The rear tires are often filled with liquid ballast. In very warm climates this may be only water but in areas where the temperatures drop below freezing the solution is usually a brine solution of calcium chloride. As a result the tire valves tend to rust.
The valve assembly is a two piece assembly. You may be able to remove the outer portion and replace it without having to break down the tire and remove the tube. There is an old style and new style assembly so you want to look closely at the parts you now have before purchasing replacements. Replacement parts are available at tire stores and farm stores like Tractor Supply. If the assembly is badly corroded you will likely have to break down the tire and remove the tube to make repairs. A good tire shop can remove and vulcanize a complete new valve assembly on if the tube is otherwise in good condition. If the tube is questionable, you may be better off to replace the entire tube. When the valve assembly leaks the brine solution gets into the inside of the tire and causes the rim to rust. If this has happened you will want to remove the tire, neutralize the brine, remove the rust and refinish the rim. This work is messy and dirty and requires a pump and reservoir to remove the brine solution. You may be able to reuse the solution but if not if will have to be properly disposed of. Unless you have the necessary equipment, you will want to have this work done by a tire shop.
Once the shop removes the tire and tube flush and rinse them with water to remove any brine. A mild acid solution like white vinegar should neutralize any brine residue after you have thoroughly washed the tire, tube and rim. Flush these parts again after treating them with vinegar. Let them dry and recheck for brine residue before reusing them. There are treatments that can be applied to the rim to stop the rust. Any rust holes, deep pits or weak spots should be repaired prior to refinishing. Attempting to remove the outer valve stem may damage it and cause the brine to leak out. Be very careful if you attempt to remove the valve cap or the outer valve stem. The proper procedure is to jack the wheel up to get the weight off the tire and place the valve stem in the 12:00 position. The same procedure should be used if you are checking the pressure, adding air or adding brine.