Graco GMax 233700 Operating instructions

309409E
233705
Related Manuals
Operation 309408. . . . . . . . . . . . . . . . . . . . . . . . . .
Displacement Pump 309277. . . . . . . . . . . . . . . . .
Spray Gun 309639. . . . . . . . . . . . . . . . . . . . . . . . .
Texture Spray Gun 308491. . . . . . . . . . . . . . . . . .
Spray Tip 309640. . . . . . . . . . . . . . . . . . . . . . . . . . .
PC Board 309459. . . . . . . . . . . . . . . . . . . . . . . . . .
Drain Valve Kit 308961. . . . . . . . . . . . . . . . . . . . . .
All models are not available in all countries
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ti1839a
INSTRUCTIONS-REPAIR
Important Safety Instructions
Read all warnings and instructions in this
manual. Save These instructions.
GMax3900, 5900, 5900HD
Airless Paint Sprayers
3300 psi (227 bar, 22.7 MPa) Maximum Working Pressure
GMax 3900
Model Series Description
233701 AHi-Boy
233703 AHi-Boy with RACX tip, gun and hose
233700 ALo-Boy
233702 ALo-Boy with RAC X tip, gun and hose
GMax 5900
Model Series Description
233706 AHi-Boy
233708 AHi-Boy with RAC X tip, gun and hose
233705 ALo-Boy
233707 ALo-Boy with RAC X tip, gun and hose
GMax 5900HD
Model Series Description
233716 AHi-Boy
233717 AHi-Boy with RAC X tip, gun and hose
GRACO INC. P.O. BOX 1441 MINNEAPOLIS, MN 55440–1441
COPYRIGHT 2002, GRACO INC.
Graco Inc. is registered to I.S. EN ISO 9001

3094092
Table of Contents
Warnings and Cautions 2. . . . . . . . . . . . . . . . . . . . . . . . .
Maintenance 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Troubleshooting 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Repair
Bearing Housing & Connecting Rod 8. . . . . . . . . . . . .
Drive Housing 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pinion Assembly/Rotor/Field/Shaft/Clutch 10. . . . . . .
Clamp 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Clutch Housing 13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine 13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pressure Control 15. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Displacement Pump 17. . . . . . . . . . . . . . . . . . . . . . . . .
Parts
GMax 3900 & GMax 5900 Hi-Boy Sprayers 18. . . . .
Pinion Assembly 20. . . . . . . . . . . . . . . . . . . . . . . . . . . .
GMax 3900 & GMax 5900 Lo-Boy Sprayers 22. . . . .
Pressure Control 24. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Complete Sprayers 26. . . . . . . . . . . . . . . . . . . . . . . . . .
Dimensions 27. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Technical Data 27. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Graco Warranty 28. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Warnings and Cautions
Warning Symbol
WARNING
This symbol alerts you to the possibility of serious
injury or death if you do not follow the instructions.
Caution Symbol
CAUTION
This symbol alerts you to the possibility of damage to
or destruction of equipment if you do not follow the
instructions.

309409 3
WARNING
INJECTION HAZARD
Spray from the spray tip, hose leaks or ruptured components can inject fluid into your body and cause
extremely serious injury, including the need for amputation. Splashing fluid in the eyes or on the skin
can also cause can also cause serious injury.
Fluid injected into the skin might look like just a cut, but it is a serious injury. Get immediate medi-
cal attention.
Do not point the spray tip at anyone or any part of the body.
Do not put hand or fingers over the spray tip, and do not stop or deflect fluid leaks with your hand,
body, glove or rag.
Do not “blow back” fluid; this is not an air spray system.
Always have the tip guard and the trigger guard on the in-line valve when spraying.
Be sure the trigger safety lever operates before operating the in-line valve.
Lock the trigger safety lever when you stop spraying.
Follow the Pressure Relief Procedure on page 5 when you are instructed to relieve pressure;
stop spraying; check, clean, or service any system equipment; or install or change spray tips.
Tighten all fluid connections before each use.
Check the hoses, tubes and couplings daily. Replace worn or damaged parts immediately. Perma-
nently coupled hoses cannot be repaired.
Handle and route hoses and tubes carefully. Keep hoses and tubes away from moving parts and
hot surfaces. Do not use the hoses to pull equipment. Do not expose Graco hoses to temperatures
above 150F (65C) or below –40F (–40C).
TOXIC FLUID HAZARD
Hazardous fluids or toxic fumes can cause a serious injury or death if the fluid is swallowed or
splashed in the eyes or on the skin or if the fumes are inhaled.
Know the specific hazards of the fluid you are using.
Store hazardous fluid in an approved container. Dispose hazardous fluid according to all local,
state and national guidelines.
Dress appropriately for your application. Wear protective eyewear, noise protection for the ears, a
personal respirator, gloves, and clothing.
RECOIL HAZARD
Due to the high pressure fluid emitted, a strong recoil action may occur when you trigger the pole gun.
If you are unprepared, your hand could be forced back toward your body or you could lose your bal-
ance and fall, resulting in serious injury.

3094094
WARNING
FIRE AND EXPLOSION HAZARD
Improper grounding, poor air ventilation, open flames, or sparks can cause a hazardous condition and
result in fire or explosion and serious injury.
Ground the equipment and the object being sprayed. See Electrical Grounding on page .
Provide fresh air ventilation to avoid the buildup of flammable fumes from solvent or the fluid being
sprayed.
Extinguish all the open flames or pilot lights in the spray area.
Electrically disconnect all the equipment in the spray area.
Keep the spray area free of debris, including solvent, rags, and gasoline.
Do not turn on or off any light switch in the spray area while operating or if fumes are present.
Do not smoke in the spray area.
Do not operate a gasoline engine in the spray area.
If there is any static sparking while using the equipment, stop spraying immediately. Identify and
correct the problem.
INSTRUCTIONS
EQUIPMENT MISUSE HAZARD
Equipment misuse can cause the equipment to rupture, malfunction, or start unexpectedly and result
in serious injury.
This equipment is for professional use only.
Read all instruction manuals, tags, and labels before operating the equipment.
Use the equipment only for its intended purpose. If you are uncertain about the usage, call your
distributor.
Do not alter or modify this equipment. Use only genuine Graco parts and accessories.
Check the equipment daily. Repair or replace worn or damaged parts immediately.
Do not exceed the maximum working pressure of the lowest rated system component. This equip-
ment has a 3600 psi (25 MPa, 248 bar) maximum working pressure.
Route the hoses away from the traffic areas, sharp edges, moving parts, and hot surfaces. Do not
expose Graco hoses to temperatures above 150F (65C) or below –40F (–40C).
Do not use the hoses to pull the equipment.
Use fluids or solvents that are compatible with the equipment wetted parts. See the Technical
Data section of all the equipment manuals. Read the fluid and solvent manufacturer’s warnings.
Fluid hoses must have spring guards on both ends to protect them from rupture caused by kinks or
bends near the couplings.
Comply with all applicable local, state and national fire, electrical and other safety regulations.
Wear hearing protection when operating this equipment.
HAZARD OF USING FLUIDS CONTAINING HALOGENATED HYDROCARBONS
Never use 1,1,1-trichloroethane, methylene chloride, other halogenated hydrocarbon solvents or fluids
containing such solvents in this equipment. Such use could result in a serious chemical reaction, with
the possibility of explosion, which could cause death, serious injury and/or substantial property dam-
age.
Consult your fluid suppliers to ensure that the fluids being used are compatible with aluminum and zinc
parts.

309409 5
Maintenance
WARNING
INJECTION HAZARD
The system pressure must be manually
relieved to prevent the system from
starting or spraying accidentally. Fluid
under high pressure can be injected through the
skin and cause serious injury. To reduce the risk of
an injury from injection, splashing fluid, or moving
parts, follow the Pressure Relief Procedure
whenever you:
are instructed to relieve the pressure,
stop spraying,
check or service any of the system equipment,
or install or clean the spray tip.
Pressure Relief Procedure
1. Lock gun trigger safety.
2. Turn engine ON/OFF switch to OFF.
3. Move pump switch to OFF and turn pressure
control knob fully counterclockwise.
4. Unlock trigger safety. Hold metal part of gun firmly
to side of grounded metal pail, and trigger gun to
relieve pressure.
5. Lock gun trigger safety.
6. Open pressure drain valve. Leave valve open until
ready to spray again.
If you suspect that the spray tip or hose is completely
clogged, or that pressure has not been fully relieved
after following the steps above, VERY SLOWLY
loosen tip guard retaining nut or hose end coupling to
relieve pressure gradually, then loosen completely.
Now clear tip or hose.
CAUTION
For detailed engine maintenance and specifications,
refer to separate Honda Engines Owner’s Manual,
supplied.
DAILY: Check engine oil level and fill as necessary.
DAILY: Check hose for wear and damage.
DAILY: Check gun safety for proper operation.
DAILY: Check pressure drain valve for proper opera-
tion.
DAILY: Check and fill the gas tank.
AFTER THE FIRST 20 HOURS OF OPERATION:
Drain engine oil and refill with clean oil. Reference
Honda Engines Owner’s Manual for correct oil viscos-
ity.
WEEKLY: Remove air filter cover and clean element.
Replace element, if necessary. If operating in an
unusually dusty environment: check filter daily and
replace, if necessary.
Repack connecting rod (22) top needle bearing after
every pump change.
Replacement elements can be purchased from your
local HONDA dealer.
WEEKLY: Check level of TSL in displacement pump
packing nut. Fill nut, if necessary. Keep TSL in nut to
help prevent fluid buildup on piston rod and premature
wear of packings.
AFTER EACH 100 HOURS OF OPERATION:
Change engine oil. Reference Honda Engines Owner’s
Manual for correct oil viscosity.
SPARK PLUG: Use only BPR6ES (NGK) or
W20EPR–U (NIPPONDENSO) plug. Gap plug to
0.028 to 0.031 in. (0.7 to 0.8 mm). Use spark plug
wrench when installing and removing plug.

3094096
Troubleshooting
Relieve pressure;page 5.
PROBLEM CAUSE SOLUTION
E=XX is displayed Fault condition exists Determine fault correction from table, page 14.
Engine won’t start Engine switch is OFF Turn engine switch ON
Engine is out of gas Refill gas tank. Honda Engines Owner’s Manual.
Engine oil level is low Try to start engine. Replenish oil, if necessary.
Honda Engines Owner’s Manual.
Spark plug cable is disconnected or damaged Connect spark plug cable or replace spark
plug
Cold engine Use choke
Fuel shutoff lever is OFF Move lever to ON position
Oil is seeping into combustion chamber Remove spark plug. Pull starter 3 to 4 times.
Clean or replace spark plug. Start engine.
Keep sprayer upright to avoid oil seepage.
False tripping of WatchDog
system. EMPTY is displayed.
Pump does not run.
Operating conditions out of WatchDog param-
eters
Low pump output; page 7.
Turn pressure down. Contact Graco Technical
Assistance to adjust WatchDog parameters.
Operate without WatchDog active; Manual
309408.
Engine operates, but dis-
placement pump does not
operate
Error code displayed? Reference pressure control repair. Page 15.
Pump switch is OFF Turn pump switch ON.
Pressure setting is too low Turn pressure adjusting knob clockwise to
increase pressure.
Fluid filter (318) is dirty Clean filter. Page 24.
Tip or tip filter is clogged Clean tip or tip filter. Manual 309091.
Displacement pump piston rod is stuck due to
dried paint Repair pump. Manual 309277.
Connecting rod is worn or damaged Replace connecting rod. Page 8.
Drive housing is worn or damaged Replace drive housing. Page 9.
Electrical power is not energizing clutch field Check wiring connections. Page 13.
Reference pressure control repair. Page 15.
Reference wiring diagram. Page 25.
With pump switch ON and pressure turned to
MAXIMUM, use a test light to check for power
between clutch test points on control board.
Remove 7–pin connector from control board
and measure resistance across clutch coil. At
70F, the resistance must be between 1.2
±0.2Ω (GMax 3900); 1.7 ±0.2Ω(GMax 5900);
if not, replace pinion housing.
Have pressure control checked by authorized
Graco dealer.
Clutch is worn, damaged, or incorrectly
positioned Replace clutch. Page 10.
Pinion assembly is worn or damaged Repair or replace pinion assembly. Page 10.

309409 7
PROBLEM CAUSE SOLUTION
Pump output is low Strainer (31) is clogged Clean strainer. Sprayer 233716 strainer is for
use in paint only.
Piston ball (206) is not seating Service piston ball. Manual 309277.
Piston packings are worn or damaged Replace packings. Manual 309277.
O-ring (227) in pump is worn or damaged Replace o-ring. Manual 309277.
Intake valve ball is not seating properly Clean intake valve. Manual 309277.
Intake valve ball is packed with material Clean intake valve. Manual 309277. Do not
leave 233716 sprayer under pressure for more
than 5 minutes when spraying texture and not
actively spraying.
Engine speed is too low Increase throttle setting. Manual 309408.
Clutch is worn or damaged Replace clutch. Page 10.
Pressure setting is too low Increase pressure. Manual 309408.
Fluid filter (318), tip filter or tip is clogged or
dirty Clean filter. Manual 309408 or 309091.
Large pressure drop in hose with heavy
materials Use larger diameter hose and/or reduce overall length of hose. Use of more than 100 ft of 1/4
in. hose significantly reduces performance of
sprayer. Use 3/8 in. hose for optimum perfor-
mance (50 ft minimum).
Excessive paint leakage into
throat packing nut Throat packing nut is loose Remove throat packing nut spacer. Tighten
throat packing nut just enough to stop leakage.
Throat packings are worn or damaged Replace packings. Manual 309277.
Displacement rod is worn or damaged Replace rod. Manual 309277.
Fluid is spitting from gun Air in pump or hose Check and tighten all fluid connections.
Reprime pump. Manual 309408.
Tip is partially clogged Clear tip. Manual 309091.
Fluid supply is low or empty Refill fluid supply. Prime pump. Manual
309408. Check fluid supply often to prevent
running pump dry.
Pump is difficult to prime Air in pump or hose Check and tighten all fluid connections.
Reduce engine speed and cycle pump as
slowly as possible during priming.
Intake valve is leaking Clean intake valve. Be sure ball seat is not
nicked or worn and that ball seats well. Reas-
semble valve.
Pump packings are worn Replace pump packings. Manual 309277.
Paint is too thick Thin the paint according to the supplier’s
recommendations
Engine speed is too high Decrease throttle setting before priming pump.
Manual 309408.
Clutch squeaks each time
clutch engages Clutch surfaces are not matched to each other when new and may cause noise Clutch surfaces need to wear into each other. Noise will dissipate after a day of run time.
High engine speed at no
load
Misadjusted throttle setting Reset throttle to 3700 engine rpm at no load
l
oa
d
Worn engine governor Replace or service engine governor
Gallon counter not working Bad sensor, broken or disconnected wire.
Displaced or missing magnet. Check connections. Replace sensor or wire. Reposition or replace magnet.
No display, sprayer operates Display damaged or has bad connection Check connections. Replace display.

3094098
Bearing Housing and Connecting Rod
NOTE: The item numbers referenced are for the
Hi-Boy models. The Lo-Boy models may have different
item numbers. Use the Hi-Boy item number and part to
find the corresponding Lo-Boy part and item number.
Removal
1. Relieve pressure;page 5.
2. Fig. 2. Remove screws (14) and front cover (23).
3. For Hi-Boy models; remove spring clip (32) and
drain hose (54). Unscrew suction tube (30) from
pump, hold wrench on pump intake valve (A) to
keep pump from loosening. For Lo-Boy models;
unscrew swivel union (30aa) from pump.
4. Disconnect pump outlet hose (33) from displace-
ment pump outlet nipple (62).
5. Fig. 1. Use screwdriver to push up retaining spring
(26) at top of pump. Push out pin (29).
Fig. 1 7675B
29
26
6. Fig. 2. Loosen retaining nut (34). Unscrew and
remove displacement pump (28).
7. Remove four screws (13) and lockwashers (12)
from bearing housing (21).
8. Pull connecting rod (22) and lightly tap lower rear
of bearing housing (21) with plastic mallet to
loosen from drive housing (20). Pull bearing hous-
ing and connecting rod assembly (22) off drive
housing.
9. Inspect crank (B) for excessive wear and replace
parts as needed.
Installation
1. Evenly lubricate inside of bronze bearing (C) in
bearing housing (21) with high-quality motor oil.
Liberally pack top roller bearing (E), lower bearing
(D) inside connecting rod assembly (22) with
bearing grease.
2. Assemble connecting rod (22) and bearing housing
(21).
3. Clean mating surfaces of bearing and drive hous-
ings.
4. Align connecting rod with crank (B) and carefully
align locating pins (F) in drive housing (20) with
holes in bearing housing (21). Push bearing hous-
ing onto drive housing or tap into place with plastic
mallet.
CAUTION
DO NOT use bearing housing screws (13) to align
or seat bearing housing with drive housing. Align
these parts with locating pins (F), to avoid prema-
ture bearing wear.
5. Install screws (13) and lockwashers (12) on bear-
ing housing. Torque evenly to note 3 value in Fig. 2.
6. Refer to Displacement Pump, Installation, page 17.
8697B
21
12, 13
14
26
29
28
B
GMax 3900: Torque to 200 in-lb (22.6 Nm)
33
34
22
CE
62
Pack with bearing grease 114819
Oil
54
A
F
30
32
3
2
1
12
3
Fig. 2 Model 233701 shown
23
8697A
20
D
2
GMax 5900: Torque to 25 ft-lb (34 Nm)

309409 9
Drive Housing
Removal
1. Relieve pressure;page 5.
2. Fig. 3. Remove bearing housing. Do 1. through 8.
of Bearing Housing and Connecting Rod proce-
dure on page 8.
3. Fig. 4. Disconnect gallon counter sensor at (A).
Cut tie wrap holding gallon counting sensor
wire to clutch wire.
4. Fig. 3. Remove two screws (81) and lockwashers
(17).
5. Remove four screws (10) and lockwashers (17)
from pinion housing (19).
6. Lightly tap around drive housing (20) to loosen
drive housing. Pull drive housing straight off pinion
housing. Be prepared to support gear cluster (18),
which may also come out.
Installation
1. Liberally apply bearing grease (supplied with
replacement gear cluster) to gear cluster (18) and
to areas called out by note 3. Use full 0.62 pint
(0.29 liter) of grease for GMax 3900 and 0.68 pint
(0.32 liter) of grease for GMax 5900.
2. Place bronze colored washer (20g) on shaft pro-
truding from large shaft of drive housing (20).
Place silver colored washer (20h) on pinion hous-
ing. Align gears and push new drive housing
straight onto pinion housing and locating pins (B).
3. Install four screws (10) and lockwashers (17) from
pinion housing (19).
4. Install two screws (81) and lockwashers (17).
5. Fig. 4. Connect gallon counter sensor at (A).
Secure gallon counting sensor wire to clutch
wire with a tie wrap.
6. Fig. 3. Install bearing housing. Do 1. through 6. of
Bearing Housing and Connecting Rod proce-
dure on page 8.
TI0178A
Fig. 3
10 17
20h
20g
81
17
20
19
B
18
B
92 91
91
91
1
GMax 3900 only
1
Torque to 125 in-lb – GMax 3900
2
2
Torque to 200 in-lb – GMax 5900
2
3
3
Apply remaining grease to these areas

30940910
Pinion Assembly/Rotor/Field/Shaft/Clutch
Removal
If pinion assembly (19) is not removed from clutch
housing (5), do 1. through 4. Otherwise, start at 5.
1. Relieve pressure;page 5.
2. Remove drive housing; page 9.
3. Disconnect field cable (X) from pressure control,
and gallon counter sensor at (A).
8699A
Fig. 4 XBottom View
A
4. Fig. 5. Remove five screws (10) and lockwashers
(17) and pinion assembly (19).
10
17
10 17
Fig. 5 8700A
19
5. Fig. 6. Place pinion assembly (19) on bench with
rotor side up.
6. Remove four screws (72) and lockwashers (17).
Install two screws in threaded holes (E) in rotor.
Alternately tighten screws until rotor comes off.
8701B
Fig. 6
E
72
17