Fitting and removing tyres
An agricultural tyre must be dismounted and mounted by a trained, qualified professional, using the appropriate tools and procedures.
If these operations are handled by several people, make sure that one person at least one person is present during all operations.
Use a compressed air circuit equipped with a correctly adjusted pressure gauge.
Not following these instructions and procedures may cause incorrect mounting of the agricultural tyre onto the rim and could also cause the tyre to burst, leading to a risk of serious injury or fatality.
1- Removing the tractor tyre from the rim
- Do not try to dismount the tyre while it is still inflated.
- Required : remove the valve core.
- Ensure that the tyre is fully deflated before starting to remove it
- Never use a tool liable to damage the agricultural tyre sidewalls or beads
- Unseat the beads starting from the removal notches when present on the tyre
- Lubricate the rim flange and tyre beads to facilitate removal and avoid damage to the seats, especially when a puncture is involved
- If the rim shows apparent signs of damage, deflation is required prior to removal of the wheel/tyre assembly.
2- Preparing for fitting
- Before mounting the tyre, make sure the rim, tyre and inner tube are compatible. Check that:
- the tyre is suitable for the machine
- the diameter at the “seat" of the rim corresponds to the diameter at the “seat" of the farm tyre to be fitted (example: a 18.4 R 30 tyre, Rim: DW16L x 30)
this tyre may be fitted onto this rim.
Note: there are rims in existence with seat diameters of 15.3” – never fit. 15” tyres to these rims. The same applies to 16.1” and 16.5” diameter rims – never fit 16” tyres to these rims.
Before mounting an ag tyre onto a rim that has already been used:
The tractor rim must be clean and show no signs of damage. If the rim is not clean, use a metal brush to clean it. Never mount a tyre to a cracked, deformed rim showing signs of breaking or traces of welded repairs...
- If the tractor tyre has been used, closely examine it, inside and out, to identify any damage that may need to be repaired before mounting. If it shows signs of deterioration or degradation considered non-reparable by a specialist, replace the tyre.
- When fitting with an inner tube, always use a new inner tube suitable for the size of the tyre (inner tubes are marked with the sizes of compatible tyres). Do not fit an inner tube onto a damaged or repaired rim or one with irregularities. To fit a Tubeless tyre without an inner tube onto a Tubeless rim, ensure a new Tubeless valve is inserted each time.
Use tools that are in good condition – ones that are clean, not sharp and suitable for the tyres and rims (bead-breakers, levers, machines, etc.).
For wide or large volume tyres it is preferable to use an automated bead pusher or a bead breaker (appropriate mechanical assistance) to fit the second bead.
Before fitting the tractor tyre, lubricate the rim seats and tyre beads. Apply a fine coating of lubricant on the parts indicated in the drawing opposite. On the outside of the beads the lubricant must be applied up to 2 inches higher than the edge of the rim. The inside of the bead should also be lubed to prevent damage.
Only use products suitable for this use that will not damage the tyre: hydrocarbon-based products, silicone and antifreeze are not to be used.
3- Vertical fitting of the tyre on the rim
- Position the valve or valve hole at the bottom of the tractor wheel.
- Position the bead-breaker “window” away from the location of the valve to avoid damaging the bead on the latter.
- Place the tyre into the rim so that the first tyre bead is positioned on the edge of the rim. If applicable, adhere to the rotation direction indicated on the tyre with an arrow.
- Using a suitable lever and with successive touches around every 4-6 inches:
- Bring the first bead over the edge of the rim and push it into the deepest rim well.
- Once the first bead has been inserted:
- fix the valve, tightening the nut lightly
- if an inner tube is being fitted, position the inner tube slightly inflated inside the tyre
- For the second bead:
- bring the bead over the edge of the rim and push it into the deepest rim well.
- Finish at the valve.
- Centring the tyre, positioning of the tyre beads:
- Slightly lower the jack to approach the centring of the tyre on the rim
- Remove the valve core
- Inflate slowly and lightly to ensure the beads are in the best possible position,
- When mounting a tyre with an inner tube, check that the beads are not pinching it,
- Inflate to 35 psi without exceeding this pressure to ensure the beads are correctly positioned.
4- Inflating and seating of the beads
The safety rules to be applied are:
- Retention system to hold the agricultural tyre assembly in place (safety cage)
- A pair of protective goggles
- Safety shoes
- Safety ear muffs
If there is no safety cage or bar, the mechanic should stand as far as possible from the tyre and rim as possible.
Note: never stand in the paths indicated (Figures 1, 2, 3) to avoid any risk of physical injury in the event of an accident or incident.
To maximise safety, use an inflation gun with a calibrated pressure gauge, connected to the valve by an air extension tube at least 10 feet long, equipped with a clip system on the valve side and in perfect working order –never block the handle.
Above all, check:
- that the beads are correctly in position, centred in relation to the edges of the rim. Inflate up to 35 psi without exceeding this pressure.
- If the beads are not correctly positioned:
- deflate, lubricate again and inflate to a pressure of 35 psi
- repeat these operations until the beads are correctly in place
- replace the valve core
- tighten the valve nut by hand
- inflate to the operating pressure determined, according to the load scales indicated in the manufacturer’s documentation or to the storage pressure
- screw on the valve cap whenever a tyre has been inflated or the pressure checked because this part alone keeps the valve clean and airtight
Note: All radial tyres used at low pressure must be mounted onto good quality rims.
5- Before tyres go in to service
- When machines are being transported (by road, rail or ship), we recommend agricultural tyres be inflated to 26 psi to avoid any possible damage from certain anchorage systems.
- When the machine is put into service, the pressure must be determined and adjusted according to the load supported by the tyres and actual conditions of use.