PDF Service Manual Bobcat 337 341 Excavator - 7 MB
This in-depth service manual is the ultimate guide for repairing and maintaining the Bobcat 337 and 341 excavators.
It offers factory-approved procedures for diagnostics, disassembly, repair, and reassembly.
Complete with hydraulic and electrical schematics, this manual provides all the information a technician needs.
Keep your compact excavators performing at their best with this essential resource.
PDF Viewer
Viewer loads when you scroll here
SHARE THIS MANUAL
Download the PDF Manual
PDF viewer loading area
Text Preview from This Manual
The text below was extracted from the visible preview pages to help you confirm the manual contents before download.
--- Page 1 ---
337
341
Service
Manual
337 - S/N 234611001 & Above
341 - S/N 234711001 & Above
(G Series)
6902741 (11-09) Printed in U.S.A. ©Bobcat Company 2009
--- Page 3 ---
SAFETY INSTRUCTIONS The following publications provide information on the
safe use and maintenance of the Bobcat machine and
attachments:
Safety Alert Symbol
• The Delivery Report is used to assure that complete
This symbol with a warning statement means: instructions have been given to the new owner and
“Warning, be alert! Your safety is involved!” that the machine is in safe operating condition.
Carefully read the message that follows.
• The Operation & Maintenance Manual delivered with
the machine or attachment contains operating
information as well as routine maintenance and
service procedures. It is a part of the machine and can
WARNING be stored in a container provided on the machine.
Replacement Operation & Maintenance Manuals can
be ordered from your Bobcat dealer.
Instructions are necessary before operating or
servicing machine. Read and understand the • Machine signs (decals) instruct on the safe operation
Operation & Maintenance Manual, Operator’s and care of your Bobcat machine or attachment. The
Handbook and signs (decals) on machine. Follow signs and their locations are shown in the Operation
warnings and instructions in the manuals when & Maintenance Manual. Replacement signs are
making repairs, adjustments or servicing. Check for available from your Bobcat dealer.
correct function after adjustments, repairs or service.
Untrained operators and failure to follow instructions • An Operator’s Handbook fastened to the operator
can cause injury or death. cab. It’s brief instructions are convenient to the
W-2003-0903
operator. The handbook is available from your dealer
in an English edition or one of many other languages.
See your Bobcat dealer for more information on
translated versions.
IMPORTANT
• The AEM Safety Manual delivered with the machine
This notice identifies procedures which must be gives general safety information.
followed to avoid damage to the machine.
I-2019-0284 • The Service Manual and Parts Manual are available
from your dealer for use by mechanics to do shop-
type service and repair work.
• The Compact Excavator Operator Training Course is
DANGER available through your local dealer or at
www.training.bobcat.com or www.bobcat.com.
This course is intended to provide rules and practices
The signal word DANGER on the machine and in the of correct operation of the Bobcat excavator. The
manuals indicates a hazardous situation which, if not course is available in English and Spanish versions.
avoided, will result in death or serious injury.
D-1002-1107 • Service Safety Training Courses are available from
your Bobcat dealer or at www.training.bobcat.com
or www.bobcat.com. They provide information for
safe and correct service procedures.
WARNING • The Bobcat compact excavator Safety Video is
available from your Bobcat dealer or at
The signal word WARNING on the machine and in the www.training.bobcat.com or www.bobcat.com.
manuals indicates a potentially hazardous situation
which, if not avoided, could result in death or serious
injury.
W-2044-1107
SI EXC-0308 SM
337/341 Excavator
V Service Manual
--- Page 4 ---
LIFTING AND BLOCKING THE EXCAVATOR Figure 10-10-2
WARNING
Put jackstands under the blade and rear corners of
the undercarriage before working under the machine.
Failure to block up the machine may allow it to move
or fall and result in injury or death.
W-2218-1195
P11367
WARNING
Fully raise the blade and install jackstands under the
AVOID INJURY blade [Figure 10-10-1] and track frame [Figure 10-10-2].
Keep fingers and hands out of pinch points when
checking the track tension. Raise the boom until all the machine weight is on the
W-2142-0903
jackstands.
Figure 10-10-1 Repeat the procedure for the other side.
Stop the engine.
P11368
Raise the machine using the boom and arm [Figure 10-
10-1].
337/341 Excavator
10-10-1 Service Manual
--- Page 5 ---
RIGHT SIDE COVER
Opening And Closing The Right Side Cover
Figure 10-41-1
1
P-16613
Pull the latch up (Item 1) [Figure 10-41-1] and raise the
right side cover.
NOTE: The right side cover can be locked using the
start key.
337/341 Excavator
10-41-1 Service Manual
--- Page 6 ---
FUEL SYSTEM
Fuel Specifications
WARNING
Use only clean, high quality diesel fuel, Grade No. 2 or
Grade No. 1. AVOID INJURY OR DEATH
Always clean up spilled fuel or oil. Keep heat, flames,
The following is a suggested blending guideline which sparks or lighted tobacco away from fuel and oil.
should prevent fuel gelling problems during freezing Failure to use care around combustibles can cause
temperature explosion or fire.
W-2103-0508
Temp. F° (C°) No. 2 No. 1
Removing Water From The Fuel Filter
Above +15° (-9°) 100% 0%
Down to -20° (-29°) 50% 50%
Open the tailgate.
Below -20° (-29°) 0% 100%
Figure 10-80-2
See your fuel supplier for local recommendations.
Filling The Fuel Tank
Figure 10-80-1
1
1
P-49161
Loosen the drain (Item 1) [Figure 10-80-2] at the bottom
of the filter to drain water from the filter.
P-49110
See the Service Schedule (See SERVICE SCHEDULE
on Page 10-50-1) for the service interval when to remove
Open the right side cover and remove the fuel fill cap the water from the fuel filter.
(Item 1) [Figure 10-80-1].
Close the tailgate.
Use a clean, approved safety container to add fuel. Add
fuel only in an area that has a free movement of air and
no flames or sparks. NO SMOKING!
Install and tighten the fuel fill cap. Close the right side
cover.
Clean up any spilled fuel.
337/341 Excavator
10-80-1 Service Manual
--- Page 7 ---
LUBRICATION OF THE EXCAVATOR Figure 10-110-2
Procedure
Lubricate the hydraulic excavator as specified in the
6
SERVICE SCHEDULE (See SERVICE SCHEDULE on
Page 10-50-1) for the best performance of the machine. 5
6
Always use a good quality lithium based multipurpose
grease when lubricating the machine. Apply the lubricant
until extra grease shows.
5
Lubricate the following locations on the hydraulic
6
excavator EVERY 8-10 HOURS:
7
Figure 10-110-1 5 P-49112
4
2 5. Boom Swing Pin (3) [Figure 10-110-2]
2
6. Boom Swing Pivot (3) [Figure 10-110-2]
7. Boom Cylinder Base End (1) [Figure 10-110-2]
Figure 10-110-3
3
3
1
1
P-49114
8
Ref Description (# of Fittings)
1. Blade Cylinder Rod End (2) [Figure 10-110-1]
2. Blade Cylinder Base End (2) [Figure 10-110-1]
3. Blade Pivots (2) [Figure 10-110-1] P-49113
4. Boom Swing Cylinder Rod End (1) [Figure 10-110-1]
8. Boom Pivot (1) [Figure 10-110-3]
337/341 Excavator
10-110-1 Service Manual
--- Page 8 ---
SEAT BELT Figure 10-150-1
Inspection And Maintenance
WARNING
Failure to properly inspect and maintain the seat belt
can cause lack of operator restraint resulting in
serious injury or death.
W-2466-0703
Check the seat belt daily for correct function.
Inspect the seat belt system thoroughly yearly or more
often if the machine is exposed to severe environmental
conditions or applications.
The seat belt system should be repaired or replaced if it
shows cuts, fraying, extreme or unusual wear, significant
discolorations due to ultraviolet (UV) rays from the sun,
dusty/dirty conditions, abrasion to the seat belt webbing,
or damage to the buckle, latch plate, retractor (if
equipped), or hardware.
B-22283
The items below are referenced in [Figure 10-150-1].
1. Check the seat belt webbing. If the system is
equipped with a retractor, pull the webbing completely
out and inspect the full length of the webbing. look for
cuts, wear, fraying, dirt and stiffness.
2. Check the buckle and latch for proper function. Make
sure latch plate is not excessively worn, deformed or
buckle is not damaged.
3. Check the retractor web storage device (if equipped)
by extending the seat belt webbing to determine if it
extends and retracts the webbing correctly.
4. Check webbing in areas exposed to ultraviolet (UV)
rays from the sun or extreme dust or dirt. If the original
color of the webbing in these areas is extremely faded
and / or the webbing is packed with dirt, the webbing
strength may have weakened.
See your Bobcat dealer for approved seat belt system
replacement parts for your machine.
337/341 Excavator
10-150-1 Service Manual
--- Page 9 ---
HYDRAULIC/HYDROSTATIC SCHEMATIC
337 AND 341 EXCAVATOR
337 (S/N 234611164 – 234613190,
234613192 - 234613247)
341 (S/N 234711198 - 234713440)
(PRINTED June 2006)
V-0560legend
LEGEND
1 CROSS PORT RELIEF VALVE 17 PORT RELIEF VALVE (With 31 #3 MICRON MAIN FILTER 43 TORQUE LIMITER
(Travel Motor) 3810 PSI (263 bar) Anti-Cavitation Valve) - (Arm Cylinder) With 50 PSI (3,45 bar) By-Pass Valve 37 hp (27,6 kW) at 2500 RPM
4200 PSI (290 bar) With Normally Closed Switch
2 COUNTERBALANCE SPOOL (Travel Motor) 44 MINIMUM PUMP DISPLACEMENT
18 PORT RELIEF VALVE (With 32 HYDRAULIC RESERVOIR (PRESSURIZED) ADJUSTMENT 4.0 - 4.5 GPM
3 TWO SPEED SHIFT SPOOL Anti-Cavitation Valve) - (Boom Cylinder) with Fill Strainer (15,14 - 17,03 L/min.)
4200 PSI (290 bar) Reservoir Volume - 10 Gal. (37,9 L)
4 FLUSHING VALVE 360 PSI (25 bar) 45 LOAD CHECK (Two per Section 14 Total)
19 PORT RELIEF VALVE (With Oil Volume - 6 Gal. (22,7 L)
Only 7 Shown
Anti-Cavitation Valve) - (Boom Cylinder) PUMP PRESSURE PORT - (Capped)
33
5 LOAD SENSE BLEED CARTRIDGE 4200 PSI (290 bar) 46 COMPENSATOR - With Priority Slots
0.185 GPM (0.70 L/min.) 34 (Slew, Right Hand Travel and Left Hand Travel)
20 PORT RELIEF VALVE (With PRESSURIZED BREATHER/FILL CAP
Anti-Cavitation Valve) - (Auxiliary Return Port) 5 PSI (0,345 bar) Outlet
6 ORIFICE (Offset Base) 47 COMPENSATOR - Standard (Offset,
3000 PSI (207 bar) 0.435 PSI (0,03 bar) Inlet
0.108 in. (2,7 mm) Blade, Bucket, Arm, Boom and Auxiliary)
21 PORT RELIEF VALVE (With 40 Micron Filter
7 Anti-Cavitation Valve) - (Auxiliary Pressure Port) 35 48 SOLENOID SUPPLY - VARIABLE PILOT
ORIFICE (Offset Rod) CROSS PORT RELIEF VALVE - 2 stage
0.083 in. (2,1 mm) 3000 PSI (207 bar) 2800 PSI (193 bar) SUPPLY
22 DIAGNOSTIC COUPLER (Pump) 36 PORT RELIEF VALVE (with 49 SOLENOID VALVE - TWO SPEED
8 LOAD SENSE RELIEF VALVE
Anti-Cavitation Valve) (Blade Cylinder)
23 RETURN PORT (Capped) 3750 PSI (259 bar) 50 SOLENOID VALVE - AUXILIARY FEMALE
9 BUILD UP VALVE 105 PSI (7,24 bar) COUPLER
24 DIAGNOSTIC COUPLER (Build Up Valve) 37 PUMP MARGIN SPOOL
220 PSI (15 bar) 51 SOLENOID VALVE - AUXILIARY MALE
10 ORIFICE, STRAIGHT TRAVEL
0.031 in. (0,80 mm) 25 TWO STAGE PILOT SPOOL COUPLER
38 PRESSURE REDUCING VALVE
250 PSI (17 bar)
11 DIAGNOSTIC COUPLER (Load Sense) 435 PSI (30 bar)
26 SHUTTLE (Dual Sequence Valve)
39 ACCUMULATOR
12 AUXILIARY DIRECT TO TANK (Optional) 27 ANTI-CAVITATION VALVE Nitrogen 165 PSI (11 bar)
Precharged
28 #20 MICRON DRAIN FILTER 40 BRAKE RELEASE SPOOL
13 AUXILIARY QUICK COUPLERS
With 25 PSI (1,72 bar) By-Pass Valve 80 PSI (5,5 bar)
14 PORT RELIEF VALVE (With 29 ORIFICE, BRAKE - 0.030 in. (0,76 mm) 41 TORQUE LIMITER SUPPLY SPOOL
Anti-Cavitation Valve) - (Bucket Cylinder) With 0.031 in. (0,8 mm) Orifice NOTE: Unless otherwise specified
4200 PSI (290 bar) 30 HYDRAULIC OIL TEMPERATURE SWITCH springs have NO significant
224-234 Degrees F. 42 HYDRAULIC PISTON PUMP pressure value.
15 PORT RELIEF VALVE (With
Anti-Cavitation Valve) - (Bucket Cylinder) (107-112 Degrees C.) Minimum Displacement
4200 PSI (290 bar) 3.96 GPM (15 L/min.) at 2500 RPM
Maximum Displacement
16 PORT RELIEF VALVE (With 47 GPM (177,9 L/min.) at 2500 RPM
Anti-Cavitation Valve) - (Arm Cylinder)
4200 PSI (290 bar)
Printed in U.S.A. V-0560legend (5-23-06)
--- Page 10 ---
HYDRAULIC SYSTEM INFORMATION (CONT'D)
Troubleshooting The Travel Circuit
TROUBLESHOOTING THE TRAVEL CIRCUIT
PROBLEM CAUSE CORRECTION
Travel system inoperable. Pilot pressure too low. Repair or readjust.
Console switch not closed. Repair or replace.
Excessive joystick leakage. Repair or replace.
Lever linkage incorrectly adjusted. Readjust.
Track tension too tight. Readjust.
Defective pump. Check, repair or replace.
Travel motor counter balance spool sticking. Repair or replace.
Travel motor internal leakage excessive. Repair or replace.
Travel motor defective. Repair or replace.
Travel motor gears defective. Repair or replace.
Swivel joint defective. Repair or replace.
Pump pressure too low. Readjust.
Travel power. Track tension too tight. Readjust.
Travel motor check valve leaking. Readjust or replace.
Pump pressure too low. Readjust.
Torque limiter. Readjust.
Swivel joint leaking. Repair or replace.
Travel motor counterbalance spool sticking. Repair or replace.
Travel speed too slow. Engine RPM low. Readjust.
Pilot pressure low. Readjust.
Pump margin too low. Readjust.
Lever linkage incorrectly adjusted. Readjust.
Swivel joint internal leakage excessive. Repair or replace.
Control valve internal leakage excessive. Repair or replace.
Low pump pressure. Check, repair or replace.
Travel motor internal leakage excessive. Repair or replace.
Travel motor seal leakage. Return line filter plugged. Inspect, clean or replace.
Machine not running straight. Straight travel orifice plugged. Repair or replace.
Lever linkage incorrectly adjusted. Readjust.
Track tension not equal. Readjust.
Travel motor internal leakage not equal. Repair or replace.
Travel motor counter balance spool sticking. Repair or replace.
Pump pressure set too low. Repair or replace.
Swivel joint internal leakage excessive. Repair or replace.
Control valve internal leakage not equal. Repair or replace.
Machine will not hold on slope Valve compensators not equal. Repair or replace.
or while digging. Travel motor counterbalance valve leakage Repair or replace.
excessive.
Blade drops while machine Lever linkage unaligned. Readjust.
is moving. Cylinder internal leakage excessive. Repair or replace.
Control valve internal leakage excessive. Repair or replace.
Swivel joint internal leakage from travel motor Repair or replace.
pressure circuit into blade cylinder circuit.
High/low gear switch inoperative Control valve defective. Replace.
(2-speed). Torque limiter set too low. Readjust.
Pump pressure set too low. Readjust.
Switch defective. Replace.
Faulty pressure reducing valve. Repair or replace.
Bad solenoid. Replace.
337/341 Excavator
20-10-7 Service Manual
--- Page 11 ---
BOOM CYLINDER (CONT'D) Figure 20-20-20
Disassembly (Cont'd)
Figure 20-20-18
1
2
1
P-53160
1 Remove the seal (Item 1) [Figure 20-20-20].
P-81032
Figure 20-20-21
Insert the adjustable gland nut wrench into the holes
(Item 1) [Figure 20-20-18] to loosen the head.
2
2
Remove the head and the rod assembly (Item 2) [Figure
20-20-18] from the cylinder.
Put the rod end in a vise.
Figure 20-20-19
1
P-53161
Remove the backup ring (Item 1) [Figure 20-20-21].
NOTE: If the fiber surface (Item 2) [Figure 20-20-21] on
the piston head becomes damaged, the
4 complete piston head must be replaced.
3
1 2
P-53159
Remove the nut (Item 1), piston (Item 2), spacer (Item 3),
and head (Item 4) [Figure 20-20-19].
337/341 Excavator
20-20-7 Service Manual
--- Page 12 ---
ARM CYLINDER (CONT'D) Figure 20-21-8
Removal and Installation
Lower the boom/bucket and blade to the ground.
With the engine off, turn the key to the ON position and
move both hydraulic control levers to relieve hydraulic
pressure.
Figure 20-21-6 2 1
1
P-50714
Remove the snap ring and washers (Item 1) [Figure 20-
21-8] from the rod end of the arm cylinder.
Remove the pin (Item 2) [Figure 20-21-8].
Raise the hoist to access the base end hose.
P-50711 Figure 20-21-9
Support the boom with a chain hoist [Figure 20-21-6].
Figure 20-21-7
1
1
1
P-50715