Enerpac VM43-LPS Manual Del Usuario página 6

In diagnosing malfunctioning valves, certain symptoms may be
common not only to valves, but often to hydraulic equipment
in general. Before repairing the valve, mount a different VM32
onto the pump and verify that the problem is not with the
pump.
TROUBLESHOOTING:
CAUTIONS:
Standard safety procedures are to be followed during
assembly to minimize any possibility of injury.
danger.eps
1. Inability to obtain any pressure may be the result of
damaged connector seals on the pump, or failed relief valve
components (items 6, 7, figure 6) a damaged seat (figure 6),
or damaged or worn shear seals and disc (item 16, 18, figure
3). These problems are usually a symptom of contaminated
hydraulic oil. The system should be drained and refilled with
fresh ENERPAC hydraulic oil.
2. Pressure leaks that
proportionately with increasing pressure ranges are usually
the result of leaking gaskets or threaded surfaces such as
NTPF fittings or plugs.
3. Ball seat leakage is often erratic and intermittent and is
caused by contaminants trapped on the sealing edge. Over
time, as wear occurs, these seats will need to be replaced.
4. Leakage observed on the external surfaces around the shaft
(item 13) is an indication that the o-ring (item 15) and
backup ring (item 14) needs to be replaced.
5. Leakage observed on the external surfaces around the relief
valve body (item 1) is an indication that the o-ring (item 8,
figure 7) needs to be replaced.
DISASSEMBLY:
1. Remove the 4 socket head cap screws and remove the
valve from the pump.
2. Remove the return tube and gasket.
3. Remove the screw (item 1) and washer (item 2) from the
shaft (item 13, Figure 3).
4. Remove the handle (item 3).
5. Remove the 4 socket head cap screws (item 62, fig.1) and
remove the upper valve assembly (item 51) from the locking
power seat (item 50).
6. Remove the 2 socket head cap screws (item 24) and
separate the body (item 23) from the valve cap (item 9).
7. Remove the shaft assembly and inspect the o-ring (item 15)
and backup ring (item 14) for damage. Replace if needed.
8. Remove the o-ring (item 10) and inspect for damage such as
nicks or cuts. Replace if needed.
9. Remove the bearing (item 12) and bearing plate (item 11)
and inspect for damage. Replace if needed.
10. Remove the shear seal assembly from the bores in the body.
11. Remove the o-ring (item 20) and backup washers (item 19)
and inspect for damage. Replace if needed.
12. Remove springs (item 22) and inspect for damage such as
breakage or permanent set. Replace if needed.
All manuals and user guides at all-guides.com
TROUBLE SHOOTING AND REPAIR OF VM43-LPS MANUAL VALVE
are consistent and increase
13. Disassembly of the manifold is as follows:
14. Loosen lock nut (item 9, figure 6) and unscrew the set screw.
(item 2, figure 6).
15. Using a 7/8" socket, loosen and remove the relief valve
assembly (item 58, figure 5) from the body.
16. Remove the seat (item 57, figure 5) from the body.
17. Inspect the seat for damage such as nicks or dents on the
sharp edge of the internal diameter. Replace if necessary.
18. Inspect the o-ring (item 8, figure 6) for damage and replace
if necessary.
19. Inspect the ball (item 7, figure 6) and guide (item 6, figure 7).
Replace if necessary.
20. Remove the pipe plugs (item 53, 54, 55, figure 4) and clean
the body. Inspect body for damages.
21. Disassembly of the Locking Power Seat sub-assembly is as
follows:
22. Remove o-rings (qty. 4) (item 48) and inspect for damage
such as extrusion of material or cuts or cracks.
23. Remove spring guides (qty. 2) (item 32, figure 4) and inspect
o-ring and copper gasket (items 30, 31, figure 4).
24. Remove ball (item 40, figure 4), seats (qty. 2) (item 33)
inspect seat for damage.
25. Remove o-ring and backup ring (items 34, 35) and inspect
for damage.
26. Remove piston (item 42) and remove o-ring and backup
(items 37, 38) and inspect for damage.
27. Inspect the bore in item 27 for damage such as scoring.
28. Remove pipe plugs (item 44).
29. Remove adjustment screws (item 26) and remove springs
(items 43, 36, 47).
30. Remove guides (items 42, 43) and remove balls (item 41).
31. Remove pipe plugs (item 29).
32. Clean the body thoroughly and inspect ball seats for damage
such as scoring, or dents to the seating surfaces. If needed,
dress ball seats using DT-1560-1 ball hone tools or similar tool.
REASSEMBLY:
Procedure for Manifold assembly
1. Install pipe plug (item 53) and torque to 10-12 ft-lbs [13-16
Nm]. Install pipe plug (item 54, 55) and torque to 32-39 ft-
lbs) [43-52 Nm].
2. Install copper gasket (item 56) onto seat (item 57), with
round edges facing away from the seat.
3. Place seat onto the bottom counter bore in the valve body,
with the gasket side down. Note: make sure that the seat
is firmly seated and not crooked.
4. Grease o-ring on relief valve assembly and insert into cavity
in the valve body.
5. Torque relief valve assembly to 35 ft-lbs. [47 Nm] (Item 58,
figure 5).
6. If elbow (item 61, figure 5) was removed, replace with new
component if necessary.
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