Smithco Spray Star 1760 (Sn 176G012 – Current) Parts & Service Manual - Manual (Page 7)

5
Ser
vice
MAINTENANCE
ENGINE OIL
Change and add oil according to chart below based on air temperature at the time of operation. Do not overfill.
Use a high quality detergent oil classified "For Service SJ or higher" oil. Use no special additives with recom-
mended oils. Do not mix oil with gasoline.
SAE Viscosity Grades
Starting Temperature Range Anticipated Before Next Oil Change
DIRECTO VALVES
Directo Valves should be disassembled, cleaned, inspected, and a service kit installed annually. More often
depending on the chemicals being used and the frequency of use. In most cases this can be done without
removing the valve from the sprayer.
HYPRO PUMP
1. After use, flush pump with clean water.
2. Hypro diaphragm pumps come with oil in the crankcase. Hypro recommends changing oil after 40 hours of
break-in operation and every three months or 500 hours, whichever comes first. Hypro recommends a high
grade, nondetergent, SAE 30 weight oil.
3. For winter storage or if a freezing condition will be encountered, flush pump with a 50/50 mixture of water
and antifreeze.
DIAPHRAGM AND VALVE REPLACEMENT
1. Occasionally debris can cause the valves to not seal properly or damage the O-rings.
2. To check for this remove the pump manifold. With manifold removed, valves can readily be removed and
checked for debris or wear. To replace valves or o-rings, refer to the Parts List for appropriate kits.
3. Hypro recommends changing diaphragms every 500 hours or three months, whichever comes first.
4. Drain the oil from the pump by removing drain plug. Rotate the shaft to remove excess oil.
5. Remove the pump manifold, remove the diaphragm retaining bolt, support washer and diaphragm. To
replace the diaphragms order appropriate repair kit from parts list.
6. Turn the crankshaft to bring the piston to its upstroke to replace the diaphragm. Use the downstroke to
seat the new diaphragm into the sleeve groove. Install retaining washer and tighten nut.
7. Replace the pulsation dampener diaphragm by first bleeding the air from the dampener. After replacing the
diaphragm recharge dampener to 20% of operating pressure.
8. Refill crankcase with oil. Rotate shaft slowly forward and reverse to distribute oil and fill to proper level.