Terex Optima TC User manual

Tech-Tip 80 Rev. B 1 Released: 7/11/2019
Tech Tips
Service Call:
Optima TC Boom Comp Adjustment
Tools Required:
Open End Wrench - 3/8”, 7/16”, 1/2”,
5/8”, 3/4”
3/8” Socket Drive Set
Allen Wrench - 3/32”
Model(s):
Optima TC with Compensation

Tech-Tip 80 Rev. B 2 Released: 7/11/2019
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.
Do Not Perform Maintenance Unless:
•You are trained and qualified to perform maintenance on this
machine.
•You read, understand and obey:
omanufacturer’s instructions and safety rules
oemployer’s safety rules and worksite regulations
oapplicable governmental regulations
•You have the appropriate tools, lifting equipment and a suitable
workshop.
The information contained in this tech tip is a supplement to the service
manual. Consult the appropriate service manual of your machine for
safety rules and hazards.

Tech-Tip 80 Rev. B 3 Released: 7/11/2019
Tech Tips
Step 1
This adjustment is made to keep the upper
boom at or just above horizontal when the lower
boom is operated up or down.
This adjustment works best with two technicians
when adjusting the compensation. One person
operates the unit from the platform while the
second person observes the boom orientation
and adjusts the compensation. One person can
do it, but it requires climbing in and out of the
platform multiple times until the adjustment is
correct.
Step 2
Disconnect the boom overload light and remove
the lower control valve cover.

Tech-Tip 80 Rev. B 4 Released: 7/11/2019
Tech Tips
Step 3
Loosen the jam nut and adjust the pressure
compensators on the upper and lower boom
sections so that two (2) threads are showing on
the adjustment plug. Tighten the jam nut
adjustment.

Tech-Tip 80 Rev. B 5 Released: 7/11/2019
Tech Tips
Step 4
Loosen the upper boom pilot fitting and rotate it
slightly to gain access to the handle travel
adjustment. Be careful not to interfere with the
lower boom control handle travel. Retighten the
fitting.
Escaping fluid under pressure can penetrate skin causing
serious injury.
Relieve pressure before disconnecting hydraulic lines. Keep
away from leaks and pin holes. Use a piece of cardboard or
paper to search for leaks. Do not use your hand.
Step 5
Loosen the jam nut on the upper boom section
and back it off until two threads are showing on
the set screw. Screw in until the jam nut makes
contact with the valve and tighten the jam nut.

Tech-Tip 80 Rev. B 6 Released: 7/11/2019
Tech Tips
Step 6
Position the booms slightly out of the boom rest.
Using demand throttle or high throttle on a 2
speed system, operate the lower boom at full
speed through the full travel of the boom.
Step 7
Observe the position of the upper boom after
Step 6.
If the upper boom is below horizontal:
Slow the lower boom down by turning the
compensator adjustment counter-clockwise 1/2
of a turn.
Do not adjust the lower boom down more than
twice. If the lower boom has been slowed down
twice, then adjust the upper boom 1/2 of a turn
clockwise to speed up the upper boom.

Tech-Tip 80 Rev. B 7 Released: 7/11/2019
Tech Tips
If the upper boom is above horizontal:
Slow the upper boom down by turning the
compensator adjustment counter-clockwise 1/2
of a turn.
Do not adjust the upper boom speed down
more than twice. If the upper boom has been
slowed down twice, then adjust the lower boom
1/2 of a turn clockwise to speed up the lower
boom.
Note: The lower boom will speed up when past
vertical. If the upper boom isn't slightly above
horizontal at this point it will end below
horizontal when the lower boom is at full travel.
Be careful not to turn the compensators in too far to increase
boom speed. The unit can begin to demand more flow than
the pump is capable of and result in inconsistent boom
movement.
Escaping fluid under pressure can penetrate skin causing
serious injury.
Relieve pressure before disconnecting hydraulic lines. Keep
away from leaks and pin holes. Use a piece of cardboard or
paper to search for leaks. Do not use your hand.

Tech-Tip 80 Rev. B 8 Released: 7/11/2019
Tech Tips
Step 8
Position the unit with the lower boom fully
extended, the upper boom horizontal, and high
throttle (demand or two-speed) engaged.
Operate the lower boom at full speed through
the full travel of the boom until either boom is
just out of the boom rest.
Step 9
Observe the position of the upper boom after
Step 8.
If the upper boom is below horizontal:
Slow the upper boom down by turning the
handle travel limit screw clockwise 1/4 of a turn.
If the upper boom is above horizontal:
Speed the upper boom up by turning the handle
travel limit screw counter-clockwise ¼ of a turn.

Tech-Tip 80 Rev. B 9 Released: 7/11/2019
Tech Tips
Note: Adjust so when the lower boom gets to
the rest the upper boom is 1-2 feet out of the
rest. Adjust lower boom up first as lower boom
down will change.
Verify that the upper boom down works from the lower
controls before operating from the platform. The adjustment is
very sensitive and may prevent the boom from coming back
down after the adjustment is performed.
Escaping fluid under pressure can penetrate skin causing
serious injury.
Relieve pressure before disconnecting hydraulic lines. Keep
away from leaks and pin holes. Use a piece of cardboard or
paper to search for leaks. Do not use your hand.
Step 10
Perform Step 8 and 9 again as needed to check
boom position and adjust as necessary.