Yamaha PW3028A Service Manual page 11

DIAGNOSIS AND MAINTENANCE
Oil leak
 Crankcase oil seals.
 Crankshaft oil seals
and o-rings.
 Drain plug.
 Bubble gauge.
 Bearing cover.
 Filler cap.
 Replacing oil.
Pump runs extremely
rough
 Inlet conditions.
 Pump valves.
 Pump seals.
Premature seal failure
 Worn crankcase oil seals.
 Worn crankshaft oil seals or o-rings on
bearing cover.
 Loose drain plug or worn drain plug
o-ring.
 Loose bubble gauge or worn bubble
gauge gasket.
 Loose bearing cover or worn bearing
cover o-ring.
 Loose filler cap or excessive oil in
crankcase.
 Loosen filler cap
 Restricted inlet or air entering the inlet
plumbing.
 Stuck inlet/discharge valves.
 Leaking V-Packing, Hi-Pressure or
Lo-Pressure seals.
 Scored plungers.
 Over pressure to inlet manifold.
 Abrasive material in the water being
pumped.
 Excessive pressure and/or temprature
of pumped water
 Running pump dry.
 Starving pump of adequate water.
 Eroded manifold.
 Replace crankcase oil seals.
 Remove bearing cover and replace
o-rings and/or oil seals.
 Tighten drain plug or replace o-ring.
 Tighten bubble gauge or replace
gasket.
 Tighten bearing cover or replace
o-ring.
 Tighten filler cap. Fill crankcase to
specified capacity.
 Fill with CAT oil to red dot on the
bubble gauge.
 Correct inlet sized plumbing. Check
for air tight seal.
 Clean out foreign material or install
new valve kit.
 Install new seal it. Increase frequency
of service.
 Replace plungers.
 Reduce inlet pressure per
specifications.
 Install proper filtration at pump inlet
and clean regularly.
 Check pressure and inlet water
temperature.
 DO NOT RUN PUMP WITHOUT
WATER.
 Inadequate water supply, minimum
35 PSI and hose size 3/4"-5/8".
 Replace manifold. Check water
compatibilty.
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