Spearhead TWIGA 120, Handbook

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Spearhead TWIGA
120
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HYDRAULIC RAMS HYDRAULIC RAMS HYDRAULIC RAMS HYDRAULIC RAMS
General Information
Whenever possible maintenance work on the rams should be performed with the ram
removed from the machine and thoroughly cleaned off prior to dismantling on a clean work
bench.
When using a bench vice do not apply excessive pressure to the ram cylinder - use soft
metal jaws when grasping the ram rod. Scores and nicks on the ram rod should be
removed using a fine oil stone - never use a file or emery cloth as these are too abrasive
and will damage the ram rods working surface.
Seal Replacement – Standard Ø40mm Reach, Angle & Lift Rams
To change the seals on the angle, reach and Ø40mm lift rams the following procedure
applies:
• Unscrew the gland and withdraw the complete rod assembly.
• Remove piston locking nut and slide the piston and gland housing off the rod.
• Lubricate all new seals prior to assembly.
• Replace gland seals ensuring they are positioned in exactly the same location from which
they were removed.
• Carefully place the gland housing complete with seals back on the rod.
• Separate the piston halves and discard rod seals. Rebuild the piston onto the rod fitting a
new piston rod ‘O' ring.
• The piston seats can be replaced in conjunction with the above operation or alternatively,
gently prized into position after the piston and locking nut are reassembled.
• Refit the piston locking nut using ‘Permabond A713' or a similar medium strength thread
locking compound.
• Reassemble the complete rod into the ram cylinder, screw in gland housing and tighten.
Seal Replacement – Alternative Ø50mm Lift Ram
To change the seals on a Ø50mm lift ram the following procedure applies:
• Unscrew the gland and withdraw the complete rod assembly.
• Slacken piston grub screw, unscrew the piston and slide off the gland housing.
• Replace gland seals as necessary. Ensure seals are replaced in the same position from
which they were removed.
• Remove split members of the piston seal and then, using a soft lever which will not
scratch the piston, lift the remaining seal components from the piston.
• Replace with new seals in reverse order.
• Refit gland housing on the rod taking care when easing the wiper seal over the piston rod
shoulder.
The piston is locked onto the rod with a medium strength thread locking fluid such as
‘Permabond A 113', ‘Loctite Nutloc 242', ‘Dunlop Nutloc SAS101’, ‘Tru lock Nutgrade 375'
or ‘Hermetite Torqueseal M'.
Threads must be cleaned with a suitable solvent to remove oil and thoroughly dried before
applying a complete film of the locking fluid to the rod threads. The piston should be
screwed on, tightened firmly and left for 30 minutes before filling with oil and 60 minutes
before pressurising.