IMPACT 740
2.5
REPLACING THE PRIME/SPRAY VALVE
Perform the following procedure using PRIME/SPRAY valve
replacement kit P/N 700-248.
1.
Push the groove pin out of the valve handle.
2.
Remove the valve handle and the cam base.
3.
Using a wrench, loosen and remove the valve housing assembly.
4.
Make sure the gasket is in place and thread the new valve housing
assembly into the filter block. Tighten securely with a wrench.
5.
Place the cam base over the valve housing assembly. Lubricate
the cam base with grease and line up the cam with the filter block
using the dowel pin.
6.
Line up the hole on the valve stem with the hole in the valve
handle.
7.
Insert the groove pin into the valve handle and through the valve
stem to secure the valve handle in position.
Gasket
Valve Housing
Assembly
Dowel Pin
Cam Base
Valve
Groove Pin
Handle
2.6
SERVICING THE FLUID SECTION
Use the following procedures to service the valves and repack the
fluid section. Perform the following steps before performing any
maintenance on the fluid section.
1.
Loosen and remove the four front cover screws. Remove the
front cover.
2.
Stop the sprayer at the bottom of its stroke so that the piston is
in its lowest position.
3.
Perform the Pressure Relief Procedure and unplug the sprayer.
Before proceeding, follow the Pressure Relief
Procedure outlined previously in this manual.
Additionally, follow all other warnings to reduce
the risk of an injection injury, injury from moving
parts or electric shock. Always unplug the sprayer
before servicing!
4.
Remove the return hose from the clamp on the siphon tube.
5.
Unscrew the siphon tube/siphon set from the foot valve.
6.
Loosen and remove the high-pressure hose from the nipple on
the back of the upper housing of the fluid section.
Filter
Housing
Valve Stem
SERVICING THE VALVES
The design of the fluid section allows
access to the foot valve and seat as well
as the outlet valve and seat without
completely
disassembling
section. It is possible that the valves may
not seat properly because of debris stuck
in the foot valve seat or outlet valve seat.
Use the following instructions to clean the
valves and reverse or replace the seats.
1.
Loosen and remove the foot valve
housing from the lower housing.
2.
Clean out any debris in the foot valve
housing and examine the housing
and the foot valve seat. If the seat
is damaged, reverse or replace the
seat.
3.
Using two wrenches, hold the upper housing at the wrench flats
with one wrench and loosen the lower housing with the other.
Remove the lower housing.
4.
Using a 3/8" wrench, loosen and remove the outlet valve retainer
from the piston rod.
Always service the outlet
i
valve with the piston rod
attached to the pump.
This will prevent the
piston rod from rotating
during
disassembly of
the outlet valve.
5.
Clean out any debris and examine the
retainer and outlet valve seat. If the
seat is damaged, reverse or replace the
seat.
6.
Remove, clean, and inspect the outlet
valve cage and outlet valve ball.
Replace if they are worn or damaged.
7.
Reassemble the valves by reversing the
steps above.
During reassembly, make sure the Viton o-rings
i
and the PTFE back-up rings between the upper
housing and lower housing as well as between
the lower housing and the foot valve housing are
lubricated with grease and in position.
MAINTENANCE
Upper
Housing
Lower
Housing
Foot Valve
the
fluid
Cage
Foot Valve
Ball
Foot Valve
Seat
O-ring
Viton
O-Ring
PTFE
Back-Up
Ring
Foot Valve
Housing
Upper
Housing
Piston Rod
Outlet Valve
Seal
Outlet Valve
Cage
Outlet Valve
Ball
Nylon
Washer
Outlet Valve
Seat
Outlet Valve
Retainer
Lower
Housing
9