Graco Inc. 800-707 Pressure Washer User Manual


 
16
308–532
PUMP
SER
VICE
Servicing the Valves
1. Remove
the hex valve plug.
2. Examine the o–ring under the plug for cuts or
distortion
and replace if worn.
Lubricate new o–ring
before
installing.
3. Grasp valve retainer by tab at the top with pliers
and remove from valve chamber . V alve parts
usually
separate during removal.
Note: A special tool will be needed to remove the
seat from the manifold. A reverse pliers or a
standard
vise grip and a 1/4” x 3” bolt to fit I.D.
of seat inserted under the edge of the seat,
will
pry the valve seat out easily
.
4. Examine all valve parts for wear and replace with
preassembled valve assembly in service kit
containing retainer , spring, valve, valve seat,
o–ring,
and back–up ring.
5. Grasp
new valve assembly by tab at top with pliers,
immerse in oil and push into valve chamber . Be
certain
valve assembly is square
in valve chamber
.
6. Apply
Loctite 242 to valve plug,
thread into manifold
port
and torque per chart.
Note: Corrosion Resistant models require the coil
spring
installed in the V
alve Plug.
Servicing the Pumping Section
Disassembly:
1. Remove
the four (4) hex nuts or two (2) bolts from
the
manifold (varies with model).
2. Rotate crankshaft by hand to start separation of
manifold
from
crankcase. Support the underside of
the
manifold and tap lightly
with a mallet to remove
the
manifold assembly
.
CAUTION
Keep manifold properly aligned with ceramic
plungers when removing to avoid damage to
either
plungers or seals.
3. Remove oil pan and slide out seal retainer with
wicks.
4. Using
a wrench, loosen the plunger retainer
. Grasp
ceramic plunger and push toward crankcase until
plunger
retainer pops out.
5. Remove plunger retainer with copper gasket,
back–up
Ring and o–ring.
6.
Remove plunger from plunger rod.
Reassembly:
1. Carefully examine each ceramic plunger for
scoring or cracks, replace if worn and slip onto
plunger rod.
Note: Ceramic plunger can only be installed one
direction (front to back). Do not force onto
rod.
2. Examine plunger retainer and stud and replace if
worn.
Note: Thread
stud into plunger retainer
.
3. Examine o–ring, back–up ring and gasket on
plunger retainer and replace if worn or cut.
Lubricate
o–ring for ease
of installation and to avoid
damaging
o–rings.
Note: First install gasket, then back–up ring and
o–ring.
4. Thread plunger retainer and stud assembly into
plunger
rod. Exercise caution not to over torque.
5. Saturate
new oil wick by soaking in oil, place in seal
retainer
and slip retainer over ceramic plunger
.
6.
Replace oil pan.
7. Turn shaft by hand to line up plungers so end
plungers
are parallel.
8. Carefully slip manifold onto plungers, keeping
manifold
level, and tap
with mallet to bring manifold
flush
with crankcase.
9. Replace
washers and nuts or bolts
and torque per
chart.
Servicing the Seals and V–Packings
Disassembly:
1. Remove
the manifold as described.
2. With
crankcase side of manifold facing up, unscrew
the
seal case from the manifold using a special key
wrench.
3. Remove
o–ring from seal case.
4. Remove
snap ring and low pressure seal from the
seal case. Seals are generally removed easily
without
any tools.
5. High Pressure Seal Models: The high pressure
seal
is generally easily removed from the manifold
without
any tools. If extremely worn a reverse pliers
may
be used.
6. V–Packing Models: The female adapter , two
v–packings and male adapter are easily removed
from manifold without tools. If extremely worn a
reverse
pliers may be used.