Graco Reactor H-25 Series Repair And Parts Manual page 24

Troubleshooting
A (ISO)
Proportioning
Pump
F . 1. Proportioning System
IG
Table 2. Directional Valve Indicator Status
Left Pump Directional
Indicator Lighted
B-side pump piston valve
dirty or damaged
A-side pump inlet valve
dirty or damaged
Pressure/Material Imbalance
To determine which component is out of balance, check
the color of some sprayed material. Two-component
materials are usually a mix of light and dark fluids, so
the under-proportioned component can often be readily
determined.
When you have determined which component is
under-proportioned, spray off-target, focusing on the
pressure gauge for that component.
For example: if component B is under-proportioned,
focus on the B-side pressure gauge. If the B gauge
reads considerably higher than the A gauge, the
problem is at the gun. If the B gauge reads considerably
lower than the A gauge, the problem is at the pump.
24
A (ISO) Inlet
Supply Valve
Directional
Valve
Activator
Plate
Right Pump Directional
Indicator Lighted
B-side pump inlet valve
dirty or damaged
A-side pump piston valve
dirty or damaged
A (ISO)
Over-pressure
Rupture Disk
B (Resin)
Over-pressure
Rupture Disk
Reversing
Switch Rocker
Arm
B (Resin)
Proportioning
Pump
B (Resin) Inlet
Supply Valve
312063Z