Machine Maintenance
TANK REMOVAL
Removing the tank will be necessary to repair the pump or to replace or service internal
hoses.
1. Drain tank by removing top Filler Port Cap and Drain Plug on side of machine (See
Figure AA). A container approximately two gallons in size will be needed to drain
fl uid into.
2. Replace Drain Plug and Filler Port Cap.
3. Remove two lifting bail eyebolts and the two bolts from the back of the tank.
4. Disconnect return line on back of tank, carefully lift tank 7.6 to 10.2 cm (3’’ to 4’’)
and disconnect suction line. Tank can now be removed.
CONTROL VALVE REPLACEMENT
1. Drain tank by removing top Filler Port Cap and Drain Plug on side of machine (See
Figure AA). A container approximately 2 gallons (7.5 L) in size will be needed to
drain fl uid into.
2. Replace Drain Plug and Filler Port Cap.
3. Disconnect valve plunger from control linkage.
4. Mark positions of 4 hoses so they can be returned to their original positions.
5. Disconnect and remove 4 hoses from valve body.
6. Remove valve mounting bolts and nuts, remove valve.
7. Installation is reverse of removal procedure.
SPEED CONTROL REPLACEMENT
•
Use 3/32” allen wrench to remove plastic knob.
•
Use a 1” deep socket to remove and replace speed control valve.
•
Re-install plastic knob.
PRESSURE VALVE REPLACEMENT
This has been factory set and should not be tampered with.
•
Use a 1” deep socket to remove old unit and install new.
FORWARD SWITCH REPLACEMENT
•
Disconnect power source to unit.
•
Remove 2¼-20x½ hexhead bolts from handle. Use 7/16 diamater wrench or sock-
et.
•
Remove ¼-20 bolt from lever.
• Remove
Switch.
•
Remove 2 spade connectors from switch.
•
For switch replacement, bend the 2 prongs 90° from both ends of switch. Use old
switch as a pattern.
POWER CORD
If power cord is damaged, it must be replaced by National or its service agent, or a simi-
lar qualifi ed person in order to avoid a hazard.
FIG. BB
Fax: 763-535-8255
16
SPEED LIMIT
CONTROL KNOB
CONTROL
LINKAGE
CONTROL
VALVE
TWIST GRIP
