ARMY TM 10-4610-309-14
MARINE CORPS TM 10802A-14/1
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TACTICAL WATER PURIFICATION SYSTEM (TWPS)
UNIT MAINTENANCE PROCEDURES
HIGH PRESSURE PUMPS
NOTE
If the previous steps were performed as the initial steps of the 2000 hour PMCS,
return to and continue with step 4 of the 2000 hour PMCS procedure. If the
previous steps were performed as the initial steps of the 1000 hour PMCS,
continue with step 4 below.
4. Inspect and (if necessary) replace the piston cluster:
NOTE
The piston cluster supports the downward force of the pistons on the rotating cam
surface. During the break-in process, the piston cluster is polished-in to match the
cam surface. The piston cluster must be replaced if damage and/or wear are
discovered.
Damaged bearings may cause damage to the cam surface. Inspect and replace the
piston cluster and cam assembly as needed. It is critical during reassembly that
the pistons line up properly with the piston cluster.
a.
Inspect the piston cluster for wearing and cracking, and replace if necessary.
b.
Carefully clean and rinse the piston cluster with fresh water before installing in the pump.
c.
Add a drop of glycerin to the piston cluster cup and cam surfaces (see Figure 7).
d.
Install the piston cluster onto the camshaft cup side up (see Figure 8).
e.
Reinstall the cam spacer making sure to line up the pencil scribe marks.
PISTON CLUSTER CUP SIDE
PISTON CUP
Figure 8. Piston Cluster Installation.
5. Inspect and (if necessary) replace the body (see Figure 9).
NOTE
Inside the pump body are removable, corrosion-resistant, metal cylinder liners.
These cylinder liners may need replacement if excessive corrosion and/or wear
occur. In addition, a body-bearing supports the camshaft. If the body-bearing is
damaged or excessively worn, the bearing will need to be replaced.
a. Inspect the cylinder liners for corrosion. Replace the cylinder liners if needed.
NOTE
Corrosion inside the cylinder liner will cause wear and premature seal and/or
piston failure. If abrasives have entered the pump or corrosion has occurred,
scoring may be evident.
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