YOKE AS 4E3272 - Caterpillar

* Use extra care in handling the nitrogen gas since the gas is under high pressure. Use only nitrogen gas.(1) Preparation 1. Bring a nitrogen gas cylinder near the accumulator. * Securely hold the gas cylinder in position using a proper support.* Just before charging, reconfirm that the gas contained in the cylinder is nitrogen gas. 2. Remove valve cap (9) with a spanner. (2) Nitrogen gas charging procedure 1. Fit O-ring (7) on gas valve (5). Install and hand tighten a rotary charging valve to gas valve (5). 2. Remove the nut from the hose joint port of the charging valve with a spanner. 3. Fit an O-ring on the hose joint. Connect a charging hose to the hose joint port in place of the nut and tighten it with a spanner. 4. Connect the other and of the charging hose to the nitrogen gas cylinder. * Use a proper adaptor, if needed to connect the port of the cylinder and charging hose opening. 5. Slowly turn the T-handle of the rotary charging valve clockwise unit it stops to open the core. * Do not use excessive force to turn the T-handle. 6. Open the nitrogen gas cylinder valve by slowly turning the cylinder valve handle counterclockwise. This will allow the gas to charge into the accumulator. Stop charging when the gas pressure reaches approximately 10 kgf/cm2 (142 psi) beyond the specified level [18 1 kgf/cm2 (256 14 psi)] on the pressure gauge. 7. Turn the bleed valve of the rotary charging valve in or out until correctly adjusted to the specified pressure [18 1 kgf/cm2 (256 14 psi)]. * The gas pressure, if measured right after charged, will be higher than actual pressure because it is heated. Wait for 5 to 10 minutes after charged and adjust to the specified pressure, depending on ambient temperature. 8. Slowly turn the T-handle of the rotary charging valve counterclockwise until it stops. 9. Turn the bleed valve of the rotary charging valve counterclockwise with a spanner to completely remove gas pressure from the hose and rotary charging valve. * When the pressure gauge registers 0, turn the bleed valve clockwise. The indicator of the pressure gauge should remain zero.* If the pressure gauge registers pressures other than zero, it is an indication that the cylinder valve does not close securely and/or a trouble occurs in the core. To correct the trouble, use the procedure that follows.1) Retighten the cylinder valve securely. If doing this would not return the indicator to zero;2) Fully turn the T-handle clockwise.3) Slightly open and immediately close the bleed valve to allow small amount of gas pressure to discharge. Repeat this 2 or 3 times. This is to remove dust from sealing section of the core.4) Repeat steps (8) and (9). 10. Remove the rotary charging valve from gas valve (5). 11. Apply soapy water to core (8) of gas valve (5) and check for gas leak. * If small amount