Generac Power Systems 2500 Diagnostic Repair Manual page 10

Section 1 Pump Troubleshooting
5. Once removed, check the valve for any damage.
Also inspect the O-ring. Remove any debris within
the valve. Replace any damaged valves or O-rings.
6. To test a valve use a paper-clip to press down on
the poppet valve to see if it moves freely. Replace
the valve if there are any signs of damage or if it
does not move smoothly and freely.
Axial Pump Inlet Valve Replacement Assembly
1. Install the check valve into the manifold. Make sure
the O-ring is seated squarely in the bottom of the
manifold.
Figure 1-9. Check Valve Installed
2. Before installing the check valve inspect the O-ring
for any damage or wear. Replace the O-ring if
needed.
NOTE: If the check valve is not seated all the way it will
fall out and get smashed by the piston or cause low
pressure. Used check valves may not stay in place once
pulled out.
3. Install the seals with the flat side facing outward.
Be careful not to damage the outside of the seal.
4. Carefully place the pump head onto the pistons in
the manifold.
Figure 1-10. Pump Installation
5. Torque the bolts to 19 ft-lbs (221 in-lbs).
Servicing Triplex Pump Discharge Valves
1. Turn the ON/OFF switch to the OFF position.
8
Personal injury. Risk of fluid injection.
Do not aim spray gun at people, animals,
electrical devices, or fragile items. Keep out
of reach of children. Failure to do so
could cause death or serious injury.
2. Turn off the supply water to the pump and
disconnect the supply hose. Squeeze the trigger
on the spray gun until no water flows from the
lance. Engage trigger lock when not in use.
3. Locate the pumps valve caps. Use a 17mm socket
to remove the valve caps.
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Figure 1-11. Remove Valve Cap
4. Screw
approximately 3 inches long into the hole in the top
of the valve.
5. Using a pair of pliers, grab onto the machine screw
and pull upwards.
6. Once the valve has been removed check the valve
for any damage and also inspect the O-ring. If
there is any debris within the valve that can not be
cleaned out or the valve is damaged replace it.
7. To test a valve take a paper-clip and press down on
the poppet valve to see if it moves freely. If it does
not move freely it should be replaced.
Triplex Pump Discharge Valves Replacement
Assembly
1. See Figure
Make sure the O-ring is seated squarely in the bot-
tom of the manifold as shown.
2. Before installing the valve cap check the O-ring for
any damage. Replace the O-ring if needed.
3. Add medium strength thread locker and tighten the
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valve cap to 38 ft.-lbs (442 in-lb). Then retest.
WARNING
a 1/8" diameter machine
1-12. Install the valve into the manifold.
Diagnostic Repair Manual
(000117c)
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screw