Crane BARNES 2020HC, Installation And Operation Manual

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SECTION D: OPERATION:
D-1) Priming :
Start engine; holding governor open for maximum speed will
decrease priming time. Open gas cock (36A) in line between
pump suction and exhaust primer (36), (See Figure 1). With
exhaust primer handle (36B) and cap (36C), close exhaust
opening, this diverts engine exhaust gasses through the
venturi which creates a vacuum in the pump. When a steady
spray of water is coming from the primer, open the exhaust
and close the gas cock. (Delay the procedure if spray is not
full and steady or false prime will result.) Full prime can
usually be detected by the engine "LOADING UP" as
pumping action begins.
SECTION E: PUMP SERVICE AND REPAIR:
E-1) Check Valve Service :
Remove cap screws (70) and pull check valve body (91)
from pump body (20). CAUTION: Do not pry with sharp
instrument, but rather bump off with a block of wood and a
hammer. This will expose the check valve assembly for
examination or repair.
Examine and replace any part showing wear or damage. At
reassembly. make sure that the LARGE weight is on the
CHECK VALVE BODY side of the gasket and that the
HINGE section of gasket is at TOP.
E-2) Impeller Service:
Remove hex nuts (9B). Remove nut (9K) from gas cock (50).
Remove pump body (20) exposing square ring (13A),
impeller (15) and U-cup (21). Examine impeller inlet hub for
excessive wear and examine square ring and U-cup;
replace if required.
When impeller (15) is to be replaced, loosen impeller with a
block of wood and a hammer. The impeller thread is right
hand and to loosen turn counterclockwise.
At reassembly, handle impeller carefully so as not to
damage the impeller inlet hub, which is a machined sealing
surface and any damage to this surface will destroy the
U-cup (21). Also, make sure the spring (10A) of shaft seal
(10) and impeller shims (15A and 15B), are in place before
reassembling the impeller.
E-3) Shaft Seal Service:
To expose the seal for examination or replacement, remove
body and impeller as outlined in Paragraph E-2. Remove
spring (10A), rotating member (10B) and shaft sleeve (3)
from engine shaft. Remove hex nuts (9) and lock washers
(8D) and pull intermediate coupling (5) from engine (2). All
of the components of the shaft seal are now exposed for
examination or repair. If any part of the shaft seal shows
wear or damage, replace entire seal assembly.
When stationary member (10C) needs replaced, press used
stationary member out of intermediate coupling (5).
CAUTION!
HANDLE SEAL PARTS WITH EXTREME CARE. DO
NOT SCRATCH OR MAR LAPPED FACES.
Lightly oil seal cavity in intermediate coupling (5). Lightly oil
ring of stationary member (10C) and press stationary
member into intermediate coupling. Reassemble
intermediate coupling (5) onto engine (2).
Fig. 1
Fig. 2
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