Changing A Rear Tire Manually
(With Calcium Chloride Ballast)
Oliver 77 Industrial
I recently had to change one of the rear tires on my Oliver and thought I'd do a write-up showing how I do it. This is basically for those who have never done it themselves and want to try and those that have and swore never to do it again but might want to try if it was easier. Those who do it regularly and those who prefer, for whatever reason, to hire it done by others will not get anything out of it.
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The first thing do do is to drain the calcium ballast out and save it for reuse with the new tire. Jack up the tractor so the entire wheel can be rotated by hand. Rotate it so that the valve stem is at the top and let the air out of the tire. After all the air is out, attach a fluid adapter and a garden hose to the open valve stem. You will need to place buckets to hold the calcium solution and place them low enough below the bottom of the tire such that fluid will drain by gravity from the tire to the buckets. If you cannot locate buckets low enough for a gravity drain, you'll need to pump the solution out using a small transfer pump that I'll get to later. Once everything is set, rotate the tire so that the valve stem is at the bottom and the solution will drain out by gravity (or be pumped out if that is your needed method). Here's an overview of the draining process:
The photo on the left shows the valve stem at the bottom and the adapter and garden hose attached. I was able to locate the buckets, shown in the photo on the right, low enough below the bottom of the tire such that the solution would drain by gravity. The fluid adapter is shown up closer in the center photo. You won't be able to drain all the solution out. There will be some number of gallons left below the valve stem. But you'll get most of it out and that will enable removal of the tube after the tire beads are broken down. The tire is a 16.9x26 that takes about 65 gallons of solution to fill to the valve stem level when the valve stem is on top.
To break down the beads I am using a tool called a "Bead Cheater" or "Bead Buster" sold by Gemplers. It's a great little tool and saves a lot of muscle, sweat and aggravation on breaking down large tractor tires. I've used the sledge hammer and wedge methods in the past but this tool makes real easy work of it. It can easily break both beads while the rim is still on the tractor.
The photo on the left shows what it looks like and the one on the right shows it in action. The tool is first driven down between the bead and the rim with a heavy hammer. It is then clamped to the rim with the cam lever and a regular ratchet or other common wrench is used to turn it down and break the bead. It is basically a specialized mechanical jack and works slick.
Once the both beads are broken down, one of the beads is removed from the rim using manual tire irons. It helps to have four hands here but one can do it alone with some patience. Here's a photo with the first bead partially removed:
Here's a tip for deciding which side of the tire to remove first. If your rim is a dropped center rim with the dropped center off center to one side, I've found it much easier to remove the tire from the the side that the dropped center is closest to. Remember this when removing the first bead on removal and also on the first bead down during installation.
After the first bead is removed, the tube is removed by sliding out between the rim and that first bead. It is easier to set the tire upright, roll it so the valve stem is on the top, slide the rim to one side, remove the valve stem from the rim and slide the tube down and out. The remaining calcium solution in the tube (about 10 gallons in my case) will make it a little harder towards the end but doing a little at a time will result in success.
Once the tube is out, the other bead is removed similar to the first one with the tire irons. It always seems to me that the second bead off and the first bead back on is the hardest so don't be discouraged at this point. Lubrication of the bead (I use dish washing liquid) helps. Do a little bit at a time and you'll be ably to get it about half way or better. Then get the tire upright and while bearing down and out on the rim, use a hammer on the bead or some more assistance from a tire iron and the tire should come completely off.
Now is the time to clean up the inside of the rim, especially if it is rusty, as can be the case with any calcium leaks. I've found that a 4-1/2" electric grinder with a heavy twisted wire brush works best. If you have the equipment and the time, you could always sandblast for the best way of getting it ready to paint. In my case here, I'm just wire brushing the loose stuff and will give it a coat of POR15 rust paint to help preserve it. I don't expect to see the inside of this rim ever again.
The photo on the left shows the wire brush I used, the one in the middle shows the rim after a cleaning with POR's Marine Clean cleaner. A following application of POR's Metal Ready phosphoric acid prep is not shown. The photo on the right is after one coat of POR15. Two coats are recommended but timing in my case did not permit that so I only used one.
The following photo shows a method I used in trying to get as much of the remaining calcium solution out of the tube as possible. I am trying to do it in such as way as not to spill much of it. It's not really hazardous but does kill the grass. The more you can get out, the easier it will be to install the tube in the tire. If you were using a new tube, this wouldn't be needed. I saw nothing wrong with the old tube and wanted to avoid the $60 or so for a new one. The new tire was enough at over $530.
The next step is to begin mounting the tire by installing one bead. At this point you need to be careful about which side of the tire goes down first. It should go on the rim from the same side that it came off from. If you have an offset drop center rim like mine, you can install the tire with the chevron tread heading in the wrong direction and won't be able to simply switch it around on the hub and maintain your previous track width. Go through the motions first and make sure you have everything correct before mounting the first bead. Inspecting the tire and rim on the other side to confirm orientation also helps. Use lubrication on the bead (I use dishwashing detergent) and the tire irons to install that first bead.
Once the first bead is on the rim, it is time to install the tube. For car sized tires, this can be done rather easily but this tractor tire is heavy (155 lbs) and it is difficult to hold the upper bead away from the rim and insert the tube, especially with several gallons of solution remaining in it. The following photo shows the arrangement I used to make that job a little easier by using a hoist and a length of wood to hold the upper bead well above the rim.
When installing the tube, make certain that you have the valve stem on the correct side, since it usually is offset from the rim center and also in the correct peripheral location with respect to the stem hole in the rim. Stuff the tube in place between the tire and rim. Once it is all inside, you can get the stem through the hole and fasten it into place. Then you can mount the second bead using lubrication and the tire irons. Be very careful at this point to avoid getting the tube caught with an iron and the rim or caught between the bead and the rim. A pinched tube now will leak and require removal and repair. Once the last tire bead is on the rim, it's time to "seat" the beads using compressed air. Seating the beads expands them up over the outer portions of the rim into their final position. I am always a little nervous in seating beads since the procedure requires a deliberate overpressure of the tire and the beads finally pop into place with a loud sound that usually makes me jump, even when I'm expecting it. A tire like this will usually say on the sidewall what maximum pressure is safe to use when seating beads. For this tire that pressure was 35 psig. The normal maximum operating pressure for this tire (6 ply) is 18 psig. I found that these beads seated one right after the other at about 25 psig. It also helps to further lubricate the areas on the rim where the beads will finally rest. The photo below shows the tire with the beads now seated.
You can now mount the rim to the tractor hub, rotate the tire so the valve stem is on the top, drain out all the air and proceed with the filling of the calcium chloride solution - or other solution of your choice. The following photo shows the filling in progress. You'll notice in the photo that when I drained out all the air, the tire beads (both of them) dropped down from their seated position. They'll have to be reseated again after the solution is in place.
The fluid adapter is again used together with a small electric transfer pump and some garden hose. After a number of gallons are pumped into the tire, stop the process and drain out the air that gets compressed by being displaced by the incoming fluid. You do this by depressing the small button on the side of the adapter. This relieves the air and then you can continue pumping some more fluid in. I stopped three times to do this for the 60 or so gallons that I pumped back in. I also found that it is faster to forget depressing the button and simply remove the adapter temporarily. It takes only a few seconds and the built up air pressure drains off quicker than through the small hole via the button.
After the filling was completed, I reseated the beads. It took about the same 25 psig that it took the first time. I then drained the air out again and installed the valve core. The beads stayed in place this time, probably because all the solution inside helped to prevent their collapse. I then added air to the tire up to the normal maximum operating pressure of 18 psig. After reinstalling the tire chain, the job is complete.
Many people are dead set against using calcium chloride as tire ballast because of the potential for severe damage to rims. That does indeed happen but doesn't have to. The problem, of course, is caused by not using tubes to contain the calcium solution and by lack of attention and regular maintenance. The calcium will eventually eat away the valve core and the stem will begin to leak. Once this happens, the solution will wick up around the valve stem and get into the interior where the chemical action will, in time, eat away the steel rim. The action is concentrated around the valve stem opening but can also be discovered around most of the rim. Most of the rims you see that have been severely damaged are eaten completely away in the vicinity of the valve hole. When that happens, the fix is either to weld in steel repair patches or replace the rim. To avoid this problem, I keep a careful eye out for any sign of leakage by the valve core. If I notice any, I know it's time to replace it before the problem gets out of hand. I also replace the cores every five years, even if they are not leaking, as a precaution. It's cheap maintenance insurance. I've used calcium in tires for ballast in the rear tires on my AC-B and both the front and rear tires on my Oliver 77 for about 40 years now. I have never had to replace a rim because of calcium damage. Dad used it in the B well before I did. Liquid ballast is a little preferable to the same amount of cast wheel weights because it provides a lower center of gravity. And a calcium solution is probably the most efficient in terms of potential pounds added per gallon. A 15% solution (2.0 lbs of flake per gallon of water) weighs 9.5 lbs. A 30% solution (4.0 lbs of flake per gallon of water) weighs 10.8 lbs per gal.
I use about a 15% solution of calcium flake and water. That adds about 600 lbs to each of the Oliver rears. Some use a higher percentage to avoid freezing in cold weather but that's not really necessary unless severe lows are experienced. A salt solution such as calcium chloride is a brine that has characteristics that are a bit unusual. With a 15% solution, the initial freeze point will be reached at about 10 degrees F above zero. But the solution will not freeze solid at this temperature. What happens is that water ice crystals will begin to form throughout the mixture and it will turn to a slush as the temperature drops further. As that happens, the remaining solution becomes more concentrated because more water has been removed from solution in the form of ice crystals and the freezing point is lowered. A 15% calcium solution will not freeze solid, even at 20 below zero F, the coldest it gets in my area. The slush that does form will not harm the tire or tube in any way and will not be noticeable when driving the tractor. I have never had a freezing problem with a 15% solution. Now if I had regular temps to minus 60F, I would increase the calcium percentage accordingly. There is an advantage in higher percentages at milder temperatures however, since the greater the calcium concentration, the greater the increase in weight per gallon of solution. If you think you want to have still more weight for a fixed volume, increase the percentage to 30% (4 lbs flake/gal water).