Multiquip LS-300P - Manual (Page 48)

PAGE 48 — MAYCO LS300P CONCRETE PUMP • OPERATION MANUAL — REV. #0 (06/09/14)
Wear Plate and Cutting Ring
Due to the abrasive nature of concrete, it is normal for the
cutting ring to wear on its sides as it shears through the
concrete inside the hopper. The metal-to-metal friction and
the abrasiveness of the concrete will cause extreme wear
and reduce sealing capability between the cutting ring and
wear plate.
If the two components do not properly seat against each
other, slurry will pump into the hopper rather than out the
discharge line. See Figure 51. This condition can easily
be observed.
1. The sudden change of the level of concrete inside the
hopper during each pumping stroke.
2. Concrete slurry squirting into the air from the hopper
(volcano effect).
3. When the output volume at the end of the delivery line
decreases in pressure.
4. Unusual frequent material packs in the Shuttle tube.
It is important that the wear components (Figure 51) be
inspected weekly for proper sealing. Failure to inspect
will eventually cause severe damage to the nun-plate and
material cylinders. Visually inspect wear plate and cutting
ring to ensure surfaces are sealed against each other.
Figure 51. Wear Plate and Cutting Ring
GOOD SEAL LEAKING
SHUTTLE TUBE
(INSIDE HOPPER)
RUBBER
ENERGIZER
WEAR
PLATE
CUTTING
RING
MAINTENANCE
If a deep groove or a wide space has developed on the
sealing surfaces, it is time for replacement. Due to the
motion of the shuttle tube, the cutting ring experiences
a quicker rate of wear as opposed to the wear plate. The
wear ring typically requires replacement two times per wear
plate (2 to 1). When replacing the wear ring, also replace
the rubber energizer ring.
Changing the Concrete Cylinder Piston Cups
The urethane piston cups will occasionally require
replacement depending on the following factors.
„ The fluid level and cleanliness of the lubrication box.
„ The size and type of aggregate.
„ The type of concrete being pumped.
It is time to replace the cups when increasingly large
particles of sand and cement pass into the lubrication box.
DO NOT allow the cups to become so worn that they begin
to pass lubrication into the material cylinders.
If the liquid level of the lubrication box becomes to low, the
rubber cups will severely deform due to excessive heat.
Whenever replacement is due, both cylinder cups should
be replaced.
DANGER
AMPUTATION HAZARD
D u r i n g r o u t i n e
m a i n t e n a n c e o r
removing material
blockage, you will be
required to put your
hand in the concrete
cylinders or near the
shuttle tube. You are at extreme risk of injury or
AMPUTATION if the engine is running or if pressure
is in the hydraulic system.
Prior to performing any maintenance on the pump,
follow described lock out-tag out procedures. Stop the
engine by turning off the ignition switch and remove
the starter key.
Place a
DO NOT OPERATE tag over the switch and
disconnect the battery. The pressure reading on the
pressure gauge MUST read zero.