Troubleshooting Guide - Graco BULLDOG 204–287, Series K Instructions–parts list Instructions Manual

Pressure Relief Procedure
To reduce the risk of serious bodily injury, including fluid injec-
tion, splashing in the eyes or on the skin, or injury from moving
parts, always follow this procedure whenever you shut off the
pump, when checking or servicing any part of the spray/dis-
pensing system, when installing, cleaning or changing spray
tips/nozzles, and whenever you stop spraying/dispensing.
1. Engage the gun/valve safety latch.
2. Shut off the air to the pump.
3. Close the bleed–type master air valve (required in your
system).
4. Disengage the safety latch.
5. Hold a metal part of the gun/valve firmly to the side of a
grounded metal pail, and trigger the gun/valve to relieve
pressure.
NOTE: Check everything in the troubleshooting guide below before disassembling the pump.
PROBLEM
Pump fails to operate
Pump operates but output
low on both strokes
Pump operates but output
low on downstroke
Pump operates but output
low on upstroke
Erratic or accelerated
pump speed
* To clear the pump, follow the Pressure Relief Procedure Warning, above. Disconnect the fluid line. If the pump starts when the
air is turn on, then the fluid hose or gun/valve is obstructed.

TROUBLESHOOTING GUIDE

WARNING
CAUSE
Exhausted fluid supply
Restricted line or inadequate air supply
Insufficient air pressure, closed or clogged air
valves, etc.
Obstructed fluid hose or gun/valve
Fluid dried on the displacement rod
Dirty or worn air motor parts
Exhausted fluid supply
Restricted line or inadequate air supply
Insufficient air pressure, closed or clogged air
valves, etc.
Obstructed fluid hose or gun/valve
Bleeder valve open or worn
Air leaking into supply drum
Fluid too heavy for pump priming
Worn throat packings in displacement pump
Fluid too heavy for pump priming
Held open or worn intake valve or packings
Held open or worn piston valve or packings
Exhausted fluid supply
Fluid too heavy for pump priming
Held open or worn piston valve or packings
Held open or worn intake valve or packings
Worn throat packings in displacement pump
6. Engage the gun/valve safety latch.
7. Open the drain valve and/or the pump bleeder valve (re-
quired in your system), having a container ready to catch
the drainage.
8. Leave the drain valve open until you are ready to use the
system again.
If you suspect that the spray tip/nozzle or hose is completely
clogged, or that pressure has not been fully relieved after fol-
lowing the steps above, VERY SLOWLY loosen the tip guard
retaining nut, nozzle, or hose end coupling and relieve pres-
sure gradually, then loosen completely. Now clear the tip/noz-
zle or hose.
SOLUTION
Refill and reprime or flush.
Clear; see TECHNICAL DATA on back cover.
Open, clear.
Clear.*
Clean. See SERVICE.
Clean, service. See air motor manual, supplied.
Refill and reprime or flush.
Clear. See TECHNICAL DATA on back cover.
Open, clear.
Clear.*
Close; replace.
Check inductor or ram plate seal.
Use pump bleeder valve (see page 5). Use inductor or
ram unit.
Replace gland/packing stack.
Use pump bleeder valve (see page 5). Use inductor or
ram unit.
Clear valve; replace gland/packing stack.
Clear valve; replace gland/packing stack.
Refill and reprime or flush.
Use pump bleeder valve (see page 5). Use inductor or
ram unit.
Clear valve; replace packings.
Clear valve; replace gland/packing stack.
Replace gland/packing stack.
306–646