Pump Service - Graco A Series Instructions-Parts List Manual

Repair kits are available. See the Parts Lists (page 37). For the best results, use all parts in the kits.
Perform Pressure Relief Procedure (page 9).
Servicing Valves
Discharge Valves:
Disassembly
1. Remove valve cap.
2. Inspect valve cap o--ring for damage. Replace
if necessary.
3. Using a needle nose pliers, remove valve.
4. Use a small probe to move the poppet up and down
to assure it is functioning properly.
5. Inspect for any debris that may be lodged between
poppet and seal.
6. Remove valve seat o--ring and inspect for damage.
Assembly
1. Install valve seat o--ring squarely into bottom
of manifold.
2. Insert valve assembly squarely into port, pushing
it into o--ring.
3. Install valve cap and torque to 443 in.--lbs
(37 ft--lbs).
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Pump Service

Inlet Valves:
Disassembly
1. Remove manifold.
2. Remove low--pressure seals by inserting a flat
screwdriver under seal lip and lifting up.
3. Using a reversible pliers, carefully remove packing
retainers (plunger guides).
Note: Packing retainers can be reused if not worn.
1. Remove high--pressure packing by pulling straight
out with your finger.
2. Pull out valve cage/head ring assembly, valve
poppet, spring and o--ring.
3. Inspect for debris and/or damage.
4. Remove valve o--ring.
Assembly
1. Install valve seat o--ring squarely into bottom of
manifold.
2. Insert valve assembly and push squarely into
o--ring.
3. Install high--pressure packing by placing it into
cylinder at an angle and then pushing into place.
Note: The point of the "v" or flat side of packing is
pointed at you.
4. Lubricate packing retainer o--ring with a light film of
oil and install it into cylinder.
5. Push it completely into place.
Note: O--ring will seat just inside manifold and you will
hear a slight pop.
6. Insert low--pressure seal by placing it into cylinder at
an angle and pushing it into place.
7. Put a thin coat of oil on plungers and packings.
8. Carefully install manifold and torque bolt to
443 in.--lbs (37 ft--lbs).
Note: Valve life is dependant on many variables. Hard
water, cavitation, corrosion, chemicals and equipment
care. The valves are a wear item and need periodic
replacement. Worn o--rings or damaged valves will
cause pressure loss and pulsations.