SANDPIPER SSB2-A - Manual (Page 6)

Model SSB2-A Type 3 Page 4 ssb2dl3sm-REV0614
capscrews evenly and in an alternating cross pattern.
PILOT VALVE SERVICING
This assembly is reached by removing the air distribution valve body from the pump
and lifting the pilot valve body out of the intermediate housing.
When reinserting an externally serviceable pilot valve, push both plungers out of the
path of the pilot valve so that they and the pilot valve are not damaged.
Service Note: If a problem arises with the pilot valve, it is usually corrected by replacing
only o-rings. Always grease the spool prior to inserting into the sleeve. If the sleeve is
removed from the body, reinsertion must be from the same side it was removed from,
the chambered side. Again, grease the o-rings so that it slides into the body. Make sure
the retaining ring has securely been inserted around the sleeve.
PILOT VALVE ACTUATOR SERVICING
The bushings for the pilot valve actuators are pressed into the intermediate bracket
from the outside. The plunger may be removed for inspection or replacement from the
inside by removing the air distribution valve body and the pilot valve body from the pump.
The plungers should be visible as you look into the intermediate from the top. Depending
on their position, you may find it necessary to use a fine piece of wire to pull them out.
Under rare circumstances, it may become necessary to replace the o-ring seal. The
bushing can be pushed through the inner chamber by removing the outer chamber
assembly to reach the bushing.
TROUBLESHOOTING
1. Pump will not cycle
A. Check to make sure the unit has enough pressure to operate and that the air inlet
valve is open.
B. Check the discharge line to insure that the discharge line is neither closed nor blocked.
C. If the spool in the air distribution valve is not shifting, check the main spool. It must
slide freely.
D. Excessive air leakage in the pump can prevent cycling. This condition will be evident.
Air leakage into the discharge line indicates a ruptured diaphragm. Air leakage from
the exhaust port indicates leakage in the air distribution valve. See further service
instructions.
E. Blockage in the liquid chamber can impede movement of diaphragm.
2. Pump cycles but will not pump
A. Suction side of pump pulling in air. Check the suction line for air leaks and be sure
that the end of the suction line is submerged. Check flange bolting. Check valve flanges
and manifold to chamber flange joints.
B. Make certain the suction line or strainer is not plugged. Restriction at the
suction is indicated by a high vacuum reading when a vacuum gauge is installed in the
suction line.
C. Check valves may not be seating properly. To check, remove the suction line and cover
the suction port with your hand. If the unit does not pull a good suction (vacuum), the
check valves should be inspected for proper seating.
D. Static suction lift may be too high. Priming can be improved by elevating the suction
and discharge lines higher than the check valves and pouring liquid into the unit through
the suction inlet. When priming at high suction lifts or with long suction lines operate the
pump at maximum cycle rate.
3. Low performance
A. Capacity is reduced as the discharge pressure increases, as indicated on the
performance curve. Performance capability varies with available inlet air supply. Check
air pressure at the pump inlet when the pump is operating to make certain that adequate