Filter
Top Products
PAGE 48 — MAYCO ST-45HRM PUMP — OPERATION & PARTS MANUAL — REV. #4 (07/16/04)
NOTE
Important notice! During freezing
temperatures, completely drain the
Lubrication Box and cover the hopper
after each use. Frozen liquid will
restrict the piston travel and cause
damage to the pump.
CLEANING THE LUBRICATION BOX
1. Remove the top cover and the drain plug (Figure 47) located
at the bottom of the box and fully drain the inside of the box.
2. Once the box is drained, start the engine and stroke the
cylinder (
keep hands out of box
) ten to fifteen times.
3. While stroking, spray water inside of the box to thoroughly
clean out all contamination (Figure 47).
4. When the box is clean replace drain plug, add new
lubrication and install the top cover.
1. The lubrication level should be checked everyday prior to
pumping and maintained at a height of 5 inches or about ½
the concrete cylinder height. We reccomend a using a
soluble type oil (water & oil mixture)
CYLINDER LUBRICATION BOX
Figure 47. Cleaning the Lubrication Box
ST-45 PUMP — MAINTENANCE (PUMP)
ST45 ACCUMULATOR CIRCUIT
Figure 48. Accumulator
CHECKING ACCUMULATOR BLADDER PRESSURE
The normal accumulator charge pressure should be
approximately 1100 PSI. To check the accumulator pressure:
1. Start the engine and stroke the pump. The
accumulator
pressure gauge
(Figure 29) should read 1750 PSI.
2. To determine the
actual accumulator PSI, stop the engine
and observe the pressure gauge. As the PSI reading slowly
decreases, it will reach a point where there will be a sudden
drop in the PSI. The PSI reading should be taken just prior to
this sudden drop. If you do not read 1100 PSI, the accumulator
may require charging or bladder replacement.
When the pump cycles, a part of the stored oil is released to the
shuttle cylinder. This pressure release assures the shuttle tube
has enough force to shear the cylinder of concrete passing from
the concrete cylinder to the concrete delivery line during the
cycle phase.
CAUTION
Before checking lubrication level, stop the
engine and remove the engine starter key.
2. As the rubber piston cups naturally wear, fine cement
particles will accumulate in the box. Once the concrete paste
reaches a height of about ½ inch from the bottom of the box,
drain and clean the lubrication box.
Improper accumulator charging can result in an explosion
causing serious injury or death! NEVER use oxygen or
compressed air to charge the accumulator! Only qualified
personal should perform this procedure. Use only
dry
nitrogen
to charge the accumulator. Contact your Mayco
service department or your local Hydac representative for
proper charging procedure.
DANGER
The accumulator circuit has two functions in the hydraulic system.
■
The accumulator circuit furnishes the hydraulic pressure
to cycle the shuttle tube.
■
The accumulator circuit also furnishes the pilot pressure
necessary to activate the hydraulic system.
The accumulator circuit is equipped with
a bladder type accumulator (Figure 48)
charged with 1100 PSI of dry nitrogen.
The accumulator stores one gallon of
hydraulic oil, which is, under 1750 PSI
of pressure.