Multiquip Mayco Concrete Pump LS600 - Manual (Page 35)

MAYCO LS600 PUMP — OPERATION AND PARTS MANUAL — REV. #4 (9/15/11) — PAGE 35
CLEARING SHUTTLE TUBE BLOCKAGE
The shuttle tube is plugged if volume at the discharge end
of the hose stops and the hydraulic oil pressure gauge reads
4400 PSI or more.
To clear a plug in the shuttle tube, great care must be taken
as a dangerous condition will exist from pressure build-up
inside the shuttle tube. (With the shuttle valve, the concrete
can be pumped in reverse.) Use the following procedures
to clear the shuttle tubes.
“REVERSE” PUMPING PROCEDURE
A. Switch the pump into REVERSE. With pump
speed at a medium-slow (approx. 12 strokes per
min.) try to pull the “pack” back into the hopper
with 5 or 6 reverse strokes.
B. Remix the concrete in the hopper.
C. Switch the pump into FORWARD. If it is still
plugged, repeat “Reversing” procedure three times.
If concrete still does not move, proceed to the Shuttle Tube
Inspection Procedure.
SHUTTLE TUBE INSPECTION PROCEDURE
A. Stop the pump. Switch off the engine.
B The senior or most experienced operator must warn
all others to stand at least 20 feet away from the
machine and turn their heads to face away from
the pump.
C. The operator will position himself beside the
reducing elbow at the pump outlet. Wearing safety
glasses, slip the end of a pry bar (24" length of
reinforcing steel rod) under the latch of the hose
clamp and flip it up.
Make sure the accumulator pressure gauge reads
ZERO psi. prior to performing any maintenance or
inspection.You must follow lock out-tag out
procedures.
WARNING - ACCUMULATOR PRESSURE
LS600 PUMP — PUMPING INFORMATION
DO NOT open any of the delivery system joint clamps.
WARNING - SHUTTLE TUBES
D. Carefully knock the end of the hose away from the
reducer.
E. Chip the concrete out of the reducer with the pry
bar.
F. Remove the reducer. From the discharge end, chip
the concrete out of the shuttle tube with the pry-
bar. If concrete cannot be loosened from the outlet
of the shuttle tube, remove the clean-out plug on
the bottom of the hopper to discharge the concrete.
G. Chip the blockage out with the pry-bar.
H. Flush the shuttle tube with water.
I. Before resuming operation of the pump, perform
the “Reverse” Pumping Procedure to relieve
pressure on the shuttle tubes.