Safety unloader valve
Refer to
Fig. IPB1, pg. 6
.
If pressure
switch fails to operate, safety unloader (
1
)
activates at 3,750 to 4,250 psi
(259
to
293 bar)
lubricant pressure to relieve supply
line pressure. Safety unloader (
1
) is not ser-
viceable and must be replaced if malfunc-
tioning occurs.
Upon reassembly, tighten to 10 ft. lbf.
(
13.5 Nm
). Safety unloader is preset and
non-adjustable.
Vent valve service
1
Refer to
fig. 2
and
fig. IPB1, pg. 6
.
Loosen hose assembly (
15
) and (vent)
hose assembly (
11
).
2
Remove hex head cap screws (
40
) and lock
washers (
39
) and remove vent valve (
26
).
3
Position vent valve (
26
) in vice with vice
jaws gripping lats on vent valve base.
4
Remove elbows (
25
,
27
) and reducer
nipple (
16
).
5
Remove cylinder (
51
) with piston and
u-cup assembly (
50
).
Low level indicator
Refer to
Fig. 3
and
Fig. IPB1, pg. 6
.
If indi-
cator pin appears to drop prematurely or
water is noticeable on top of follower indica-
tor, seal may be damaged.
1
Remove bolts (
4,
18
) and washers (
19
)
holding the cover on the reservoir.
2
Inspect the reservoir gasket (
21
) for
damage and replace if necessary.
3
Remove the entire pump, vent valve and
follower assembly from the reservoir.
4
Remove the retaining ring (
57
) from the
cable assembly (
58
).
5
Hold the indicator plug (
62
) with a wrench
while removing the indicator nut (
60
).
6
Remove and replace the O-ring (
59
).
7
For assembly, torque the indicator nut
(
60
) to 20 ft-Ibs.
6
Remove packing assembly(
49
) from
cylinder (
51
).
7
Inspect needle (
52
and valve seat (
53
) for
foreign matter that may be lodged and
keeping needle (
52
) from sealing in valve
seat (
53
).
8
Clean and inspect again for damage.
Replace if valve seat (
53
) appears dama-
ged by nicks, grooves or scouring.
9
Remove valve seat (
53
) from valve body
(
54
) by placing a
3
/
4
in. open end wrench
onto the lats. Using an adjustable wrench,
turn open end wrench to loosen seat.
10
Replace valve seat (
53
) if damaged.
11
Remove and replace the check seat
gasket (
55
) below the valve seat (
53
).
12
To ease assembly, coat needle (
51
) and
cylinder (
50
) inside diameter with
lubricant.
13
Install valve seat (
53
) into valve body (
54
)
to a torque of 25 ft.lbf.
(39 Nm)
.
14
Install cylinder (
50
) onto valve body (
53
)
and tighten to a torque of 100 ft.lbf.
(135 Nm)
.
WARNING
Do not plug outlet of safety unloader.
Plugging safety unloader outlet will
result in pressure build up.
Failure to comply may result in death
or serious personal injury.
WARNING
Safety unloader ships with the pump
assembly, but is not pre-installed.
Safety unloader must be installed
before using pump. Do not operate
without safety unloader.
Failure to comply may result in death
or serious personal injury.
NOTE
If grease leakage is evident from weep
hole in hydraulic cylinder, replace pack-
ing assembly (
49
).
Fig. 3
Low level indicator
56
57
58
59
60
61
62
50
51
49
53
54
55
52
/ in. NPTF
1
4
/ in. NPTF
3
4
/ in. NPTF
3
4
Fig. 2
Vent Valve (
26
)
NOTE
Elbow (
25
) must be facing down.
Orient elbow (
27
) as shown in
Fig. IPB1, pg. 6
to prevent excessive
rubbing of hydraulic hose on pump.
4
