Hypertherm HyPrecision 100D, Instruction Manual

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7.6 Hydraulic Center Section
The hydraulic center section houses the piston and the plungers. This section describes the service of
this area with the HP cylinders removed and the center section removed from the pump.
Hydraulic Center Section Disassembly
1. Unscrew the eight bolts in the back of the manifold that connect it to the end caps.
2. With the HP cylinders removed, loosen but do not remove the four 7/8 in. cap screws that preload
the two hydraulic end caps together. Use a 3/4 in. hex x 3/4 in. deep square drive socket and a
3/4 in. hex x 13-1/2 in. hex driver.
3. Unscrew and remove the four bolts under the hydraulic end caps that secure the intensifier
assembly to the frame.
4. Place the center section on a clean workbench and remove the four 7/8 in. cap screws. Cover the
manifold oil ports to prevent contamination.
5. Pull the end caps off the hydraulic cylinder. (This will take two people).
Hydraulic Center Plunger Replacement
After extended use, the plunger surface may become damaged and/or scored.
1. Push the hydraulic piston to the end of the hydraulic cylinder so that the plunger is accessible.
Use a rubber mallet to drive the opposite plunger end. Do not remove the piston from the
cylinder. Special tooling is required to reload the piston into the cylinder.
2. Use locking snap-ring pliers on the retaining ring and remove the plunger retainer and plunger.
3. Replace the t-seal and its backups. The ID of the backup seal has a corner radius and should be
towards the t-seal. The angle-cut ends of the backup must overlap properly.
4. Squirt a small amount of hydraulic fluid in the bottom of the piston cavity and lubricate the t-seal.
5. Push the new plunger into the t-seal, replace the plunger retainer, and reinstall the retaining ring.
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