Graco Inc. 308-518 Pressure Washer User Manual


 
To reduce the risk of serious bodily injury,
including fluid injection, splashing in the eyes or
NOTE:
The following metric wrenches are needed:
MlO, Ml3 and M30. Repair kits are available.
Refer to the individual repair sections and the
pump parts page for more details. For the best
results, use all parts in the kits.
NOTE: There are two different tool kits to aid in
servicing the pump. P/N 800-298 is used to
ease installation of packings. P/N 800-271
includes the items in 800-298 and tools to aid
in the removal of packing retainers.
Valves
NOTE:
For a set of six valves, order P/N 801-472.
1.
2.
3.
4.
Remove the hex plug from the manifold using an
M30 wrench.
Examine the o-ring under the hex plug and replace
it if it is cut or distorted.
Remove the valve assembly from the cavity; the
assembly may come apart.
Install the new valve. Install the o-ring and hex plug;
torque to 75 fl-lb (103 Nm).
NOTE: Retorque the plug after 5 hours of operation.
8.
Pumping Section
1. Remove the eight capscrews and Iockwashersfrom
the manifold using an Ml 3 wrench.
2. Carefully separate the manifold from the crankcase.
NOTE:
It may be necessary to tap the manifold lightly
with a soft mallet to loosen.
I CAUT’oN
Keep the manifold properly aligned with the
1
ceramic plungers when removing to avoid
damage to the plunger or seals.
3. Carefully examine each plunger for any scoring or
cracking and replace as necessary,
Servicing the Plungers
NOTE:
Plunger repair kit, P/N 801-474 is available to
replace retainers, o-rings, washers and
backup rings for three cylinders.
1.
2.
3.
4.
5.
6.
Loosen the plunger retaining screw five to six turns,
using an Ml 0 wrench. Push the plunger towards the
crankcase to separate the plunger and retaining
screw.
Remove the screw from the plunger and examine
the o-ring, backup ring and copper bearing/gasket
washer. Replace these parts if necessary using kit
801-474.
Remove the plunger and flinger from the plunger
shaft. Clean, examine and replace parts as
necessary.
Inspect the plunger shaft for oil leakage from the
crankcase. If leaking is obvious, replace the oil
seals. Otherwise, DO NOT remove these seals as
they cannot be reused. An oil seal kit is available to
replace the seals.
Lightly grease the oil seal, if it is being replaced,
and the flinger and replace them on the plunger
shaft. Then install the plunger.
Lightly grease the retaining screw and the outer end
of the plunger. Place the washer, o-ring and backup
ring around the screw and install the screw through
the plunger. Torque to 14.4 ft-lb (19.5 Nm).
7.
Servicing the V-Packings.
Lubricate the outside of each plunger. Slide the
manifold onto the crankcase, being careful not to
damage the seals.
Install the capscrews and washers finger-tight.
Torque the screws to 21.7ft-lb (29 Nm) following the
tightening pattern (Figure 4). Uneven tightening
may cause the manifold to bind or jam.
NOTE:
If you plan to replace the packings, refer to
Figure 4
1-O 308-518