Related Manuals for Terex TM Series
Summary of Contents for Terex TM Series
- Page 1 Tech Tips Service Call: How to use the Manual Letdown on the TM series Tools Required: 7/8’’ wrench (supplied with unit) Jack handle (supplied with unit) Model(s): TM85, TM100, TM105, and TM125 Tech-Tip 57 Released: 1/9/2019...
- Page 2 Tech Tips Tech Tip Safety Rules Danger Failure to obey the instructions and safety rules in the appropriate Operator's Manual and Service Manual for your machine will result in death or serious injury. Many of the hazards identified in the operator’s manual are also safety hazards when maintenance and repair procedures are performed.
- Page 3 Tech Tips Step 1 Assess the boom position and identify any obstructions. Remember when using the manual letdown, the lowering of the upper boom, lower boom, and the lower boom extension are all done by gravity alone. None of the interlock systems will operate.
- Page 4 Tech Tips Step 2 When the manual letdown is used, none of the safety limit systems are operational. Unless the unit needs to be rotated to clear obstacles, proceed to Step 3 to retract the lower boom. If the platform or the boom is near any obstacles and needs to be rotated away before lowering the unit, rotate it by turning the far right knob to 3 o’clock.
- Page 5 Tech Tips Using the jack handle, pump up the handle until it gets hard, (you may need to keep pumping the jack intermittently to keep brake released). Push the counterbalance override on the brake valve and use the 7/8” wrench to rotate the unit. Tech-Tip 57 Released: 1/9/2019...
- Page 6 Tech Tips Rotation will be stopped when the manual override button is released. Turning the knob back to its original position will also stop rotation. If the brake valve does not have the manual override button, a lot of force is needed to rotate. You can turn the counterbalance valves in clockwise to decrease the pressure and allow manual rotation.
- Page 7 Tech Tips Step 3 To activate the lower boom extension letdown, pull the first knob on the left side and then turn to lock it in position. Pump the handle until the boom starts to come down. Always retract the lower boom extension fully before lowering the lower boom.
- Page 8 Tech Tips To stop the boom simply pull the manual letdown knob and turn back to the normal position. This will close the pilot valve stopping the movement. Step 4 Depending on what position the upper and lower booms are in will determine which boom must be lowered next.
- Page 9 Tech Tips Step 5 To activate the upper boom letdown, pull the second knob from the left and lock it in the out position. When movement stops push it back in and pump the jack up again. Next pull the third knob from the left (lower boom) until movement stops.
- Page 10 Tech Tips Step 6 If the position of the upper and lower booms allows the lower boom to be lowered, first lower the lower boom making sure that the platform does not go past center of rotation. Then lower the upper boom. It may be necessary to keep pumping the manual letdown jack to maintain pressure to the pilot valves.
- Page 11 Tech Tips Step 7 Note: Remember to return all the letdown valves back to the “in position” for Lower, Upper Boom and Lower boom Extension. Turn the Rotation back to 12 o’clock for normal operation. Before returning the unit to service and allowing anyone to operate the platform, the air that entered the cylinders while manually lowering the unit must be purged.
- Page 12 Tech Tips With lower boom raised, extend the upper boom up and down and extend the lower boom cylinder out fully before retracting. Run the cylinder through the full range of movement twice. The lower boom will not extend until it is above the minimum angle for the lower boom limit system.
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