Multiquip LS-300 - Manual (Page 40)

PAGE 40 — MAYCO LS300 CONCRETE PUMP • OPERATION AND PARTS MANUAL — REV. #4 (06/21/10)
MAINTENANCE (PUMP)
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 A. 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 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. 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.
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Figure A. Wear Plate and Cutting Ring