®®

EngineTractor Engine Cat® C15 with ACERT® technologyNet Power 246/272 kW 330/365 hp

Scraper BowlHeaped Capacity 17.5 m3 23 yd3

Rated Load 25 000 kg 55,115 lbWeights

Total Operating – empty 37 435 kg 82,530 lb

623GWheel TractorScraper

2

623G Wheel Tractor ScraperResponsible, productive earthmoving machines, built to last.

Quick loading, high travel speeds and theability to load and spread on the run yieldfast cycle times, allowing Cat ElevatingScrapers to consistently deliver highproductivity at the lowest cost per ton.

Serviceability

The latest electronic monitoringsystems, grouped service points, andrugged Caterpillar components simplifymaintenance and minimize downtime.New two-piece access doors open easilyand stay open for better access. pg. 13

✔

Elevator Mechanism

The elevator mechanism conditionsmaterial as it works, lifting materialoff the cutting edge and carrying it tothe top of the load for true self-loadingcapability. The 623G is ideal forwindrowing, blending material aswell as breaking up vegetation instripping operations. pg. 12

Electronic Controls

Electronic controls improve machineresponse and provide advanced diagnosticcapabilities that result in better machineavailability. The Product Link optionallows remote monitoring of location,machine system status, and alertindicators. pg. 7

✔

Power Train – Transmission

Planetary powershift transmissiondelivers excellent load capability.Redesigned front and rear axlesaccommodate wider brake shoes anddrums. The neutral coast inhibitor andprogrammable top gear reduce wearwhile increasing machine performance.pg. 6

✔

Power Train – Engine

Electronically controlled Caterpillar®

engines with ACERT technology,modular radiator with 9 fins per inch,and an Electronic Control Modulemaximizes power to the cutting edgeand exceptional haul road speed.pg. 4

✔

✔ New Feature

3

Customer Support

The best parts availability and the bestservice capability will help keep yourequipment working. pg. 14

Scraper Bowl

Caterpillar Scraper bowls deliver largeloads with better retention, excellentmaterial flow, fast cycle times and highproductivity. Relocating the implementvalve to the draft tube improves accessand serviceability. pg. 11

✔

Structures

Superior structural design deliversstate-of-the-art ride, capacity, andmaterial control while assuring thedurability and reliability customersexpect from Caterpillar. pg. 10

Operator Station

Convenient control placement and acomfortable work environment are keysto high productivity. Features includeSingle Lever Implement Control,an air seat suspension and improvedinstrumentation. pg. 8

C15 Tractor Engine. The Cat C15Electronically Controlled Unit Injection(EUI) diesel engine powers the tractor.With dual horsepower capability,it provides high power and torque risefor excellent lugging in tough loadingconditions. The C15 is designed forlong hours of continuous operation withhigh displacement and low RPM ratings.

Dual Horsepower. Electronic enginesdeliver increased power when the augeris engaged or when the machine is inthe roading gears, providing quickeracceleration on the haul road.

ACERT Technology. The C15 electronicengine with ACERT technology meetsUS EPA Tier 3 and European UnionStage III exhaust emission regulations.ACERT technology reduces emissionsduring the combustion process by usingadvanced technology in the air and fuelsystems, in conjunction with integratedelectronics. Caterpillar meets emissionregulations at the combustion sourcerather than recycling exhaust gases.

Electronic Control Module (ECM).The ECM responds to operatorcommands and engine sensor inputto optimize engine and machineperformance. This advanced enginemanagement software controls andprotects the engine at all times againstcold starts, high altitude operationsand air filter plugging by monitoring:

• injection timing and pressure

• engine cooling fan speed

• ether starting aid

• hydraulic pumps

ADEM™. The ADEM controls enginespeed by adjusting the fuel duration,resulting in quicker starts in hot andcold weather, better fuel economy,better operator response, and automaticcompensation for altitude and filterplugging.

Air-to-Air Aftercooling (ATAAC).Reduces air inlet temperature forenhanced combustion efficiency,reduced engine exhaust emissionslevels, higher altitude capability,and more power.

Greater Reliability. The EUI system hasfewer moving parts than mechanical unitinjection and requires few adjustments.ECM communicates with the monitoringsystem (EMS) to warn the operator ofpotential problems, reducing the potentialfor major damage from occurring.

Maintenance. EUI engines havevirtually no mechanically controlledparts to wear or adjust. These havebeen replaced by electronic controls,reducing maintenance costs andincreasing machine availability.

Control Throttle Shifting (CTS).Automatically synchronizes enginespeed to transmission speed whenshifting gears. CTS reduces power trainstress and increases component life,as well as providing a smoother ridefor the operator.

Automatic Ether Injection. ECM activatesthe ether injection system during enginecranking to help ensure reliable enginestart-up in extreme cold operatingconditions.

Directional Shift Management.During directional shifts or shiftsfrom neutral during high engine speed,engages speed clutches before directionalclutches to reduce power train energyand increase power train life.

Automatic Altitude Compensation.The Electronic Control Moduleautomatically matches fuel deliveryto barometric pressure. Auto derationprotects against excessive combustiontemperatures that could result incomponent damage.

Diagnostic Capability. ElectronicTechnician (Cat ET) is used to displayreal-time pressures, temperatures, fuelsettings and diagnostic messages as wellas historical information, such as engineover-speeds, overheating, low oil pressureand air filter restriction events.

4

The new ACERT technology and proven components are electronically integrated to achievenew levels of performance and efficiency.

Power Train – Engine

Fuel Economy. Electronic controls yielda fuel savings by optimizing the timingsetting for varying conditions. The ECMmatches timing to the load on the engine,engine speed and temperature.

Air Filter Restriction. The ECMmonitors air filter restriction and sendsa warning message to the ElectronicMonitoring System III to alert theoperator if the restriction exceeds theallowable limit.

Reduced Exhaust Smoke. The ECMdetermines the optimum fuel/air ratio,then precisely controls fuel duringcranking, starting and accelerationto reduce smoke. This system is fasterand more efficient than mechanicallycontrolling the governor rack position.

Low Battery Elevated Idle.ECM automatically compensatesfor low alternator output at low idleby raising the rpm for brief intervalsto keep the batteries fully charged.

Electronic Unit Injection (EUI).Electronic injection provides completecontrol over injection timing, duration,rate and pressure under changingconditions over the entire engineoperating range. The EUI controlledengine delivers:

• improved fuel efficiency

• more power

• decreased smoke and emissions

• faster hot and cold starts

• better high altitude performance

• less noise than mechanical injectorengines

Engine Speed Lock. Allows theoperator to maintain a given enginespeed without using the acceleratorpedal. This eliminates operator fatigueassociated with holding the pedal downfor extended periods of time. An on/offrocker switch enables the Speed Lockfeature, and a dashboard lamp indicatesthe feature is active. Moving the rockerswitch to the off position, or activatingthe service brakes or the retarder,disables the feature.

Automatic Belt Tensioning. Both thetractor and scraper engines now haveautomatic belt tensioning rather thanmanual tensioning. Other engineimprovements include:

• reducing the number of belts(from five to two on the tractor,from four to two on the scraper)

• eliminating the servicing forfan drive bearings

5

Transmission. Electronically controlledCaterpillar planetary powershifttransmission with eight forward andone reverse speed. Tractor gears 1 & 2operate in converter drive for increasedtorque capability during cut and filloperations. Gears 3-8 operate in direct-drive for drive train efficiency duringthe haul. Reverse gear operates inconverter drive.

Planetary Design. Provides largercontact area between gears thancountershaft transmissions forgreater load-carrying capacity.

Neutral Coast Inhibitor. Neutral coastinhibitor prevents the transmissionfrom shifting into neutral if the operatorselects neutral while moving, as wellas maintaining the flow of thetransmission fluid.

Transmission Hold. Allows the operatorto maintain converter drive for increasedrimpull, or hold the current gear forenhanced control.

Programmable Top Gear Selection.Allows the operator to manually set thetop gear (3rd – 8th) available to matchconditions or to match the hauling speedof the fleet to specific job-site needs.

Retarder. The hydraulic retarder actsas an internal brake on the driveline thatminimizes the need to apply servicebrakes. By engaging the retarder 3 to4 seconds before the machine traversesa downhill grade, the operator can reducewear on the service brakes and enhancemachine control.

Differential Control. Electronic differentiallock on the tractor helps prevent thedrive wheels from spinning in poorunderfoot conditions. The operatorengages the differential lock by choosingeither the right or left foot controllocated on the floor of the cab.

Brake Performance. Redesigned axles onboth the tractor and scraper accommodatewider brake shoes and brake drums,improving brake performance as muchas 20 percent and reducing brake anddrum wear as much as 75 percent.

Independent Systems. Expanding shoe-type brakes are a cam-operated designthat is air-applied and spring released.The braking system uses independentfront and rear circuits with secondarybrakes automatically applied if the serviceair pressure drops to 380 kPa (55 psi).

Parking Brakes. The push-button operatedparking brake features a spring-applied,air-released mechanism that operatesthe service brakes. All brakes meet theISO 3450: 1998 standard.

Final Drives. Outboard-mounted,planetary design final drives reducetorque loads on the other power traincomponents. Large-capacity, double-row roller bearings and CaterpillarDuo-Cone® seals deliver exceptionalreliability in the toughest applications.

6

Power Train – TransmissionIntegrated electronics allows the machine to monitor the power train which reduces stressas well as provide a better ride to the operator.

Simplified System. The electricalsystem has been redesigned to utilizethree electronic control modules (ECM)on the tractor instead of four.

Air Filter Restrictor Indicator.Electronic control module monitors airfilter restriction and sends a warningmessage to the electronic monitoringsystem to alert the operator if therestriction exceeds the allowable limit.

Automatic Ether Injection. The ECMactivates the ether injection systemduring engine cranking to enhancecold weather starting.

Automatic Altitude Compensation.At high altitudes the system automaticallyde-rates fuel delivery as a functionof barometric pressure sensed by thesystem’s atmospheric pressure sensor.

Low Battery Elevated Idle. The ECMautomatically compensates for lowalternator output at low idle to keepthe batteries fully charged.

Improved Serviceability. Combinedmonitoring systems, easy accessdiagnostics and more durable componentsmake routine maintenance and servicingsimple and fast.

Easy Access Diagnostics. Diagnosticcodes are accessible through the EMSmain display module, via the ElectronicTechnician (Cat ET). This offers a headstart on problem solving, with a radiocall often providing the service technicianwith the knowledge of which tools,troubleshooting guides, and possiblyeven replacement parts to bring tothe machine.

Greater Reliability. The Caterpillar EUIsystem has fewer moving parts thanmechanical unit injection and requiresfew adjustments. ECM communicateswith the monitoring system (EMS) towarn the operator when problems arise,reducing the potential for major damagefrom occurring.

Maintenance. EUI engines havevirtually no mechanically controlledparts to wear or adjust. These have beenreplaced by electronic controls, reducingmaintenance costs and increasingmachine availability.

Fuel Economy. Electronic controls yielda fuel savings by optimizing the timingsetting for varying conditions. The ECMmatches timing to the load on the engine,engine speed and temperature.

Product Link Ready. Product Link is awireless system that allows the customerto track machine data such as location,service meter hours as well as machinehealth information. The system has thecapability to automatically issue alertswhen the machine is being operatedbeyond owner defined time andlocation limits.

Reduced Exhaust Smoke. The ECMreads electronic sensors to determinethe optimum fuel/air ratio, then preciselycontrols fuel during cranking, startingand acceleration to reduce smoke.The ECM system is faster and moreefficient than mechanically controllingthe governor rack position.

7

Electronic ControlsInstant response optimizes machine performance, and advanced diagnostic capabilitiesmaximize machine availability.

Multi-Adjustable Seat. The Cat ComfortCloth Seat has an adjustable seat andarmrests for maximum operator comfort.

• Swivels and locks in four positions(0°, 10°, 20° and 30°) providing theoptimum operating position in thecut or on the haul.

• Fore/aft and vertical heightadjustment to accommodatevarious sized operators.

Seat Suspension. The seat suspensionredefines the ride of scrapers. It featuresa high performance air shock absorberwith its own air compressor.

Revised Steering Column. Increaseslegroom a full 3.5 inches (89 mm),and reduces knee contact points.

Standard Air Conditioning. Gives theoperator a comfortable workstation invarious types of weather. Relocatedventilation louvers improve airflowto the operator.

Storage And Amenities. Convenientstorage location includes space for alunch box and first aid kit. The cab alsohas a cup holder as well as an ashtray.

8

Redesigned for enhanced operator comfort and productivity.

Operator Station

Visibility. Hood and front shroudwidth increased to accommodate thelow emission engine, the air-to-airaftercooler (ATAAC), ether starting aid,and lights. Hood corners are sloped tomaintain the excellent visibility.

Single Lever Implement Control.Simple and easy to operate, the joystickenhances the productivity of operatorsof all skill levels. Requires lessforce to control the critical scraperfunctions and requires less lever travel.Grab handle/hand rest next to joystickcontroller so operator has a place to resthand while on the haul and return roads.

1) Bowl (forward & back)

2) Ejector (side to side)

3) Thumb rocker switch

• Apron position

• Elevator direction, speed

4) Transmission Hold

5) Cushion Hitch

6) Trigger* (not shown here –is on front of joystick)

• Auger (on/off)

• Push-Pull (bail up/down)

• Elevator (on/off, resume)

* Standard open bowl does not havea trigger

Instrument Display Panel. Features aquad-gauge layout showing enginecoolant temp, transmission/torqueconverter oil temp, fuel level, andsystem air pressure.

Logical Control Placement.Frequently used switches and indicatorlights are on the instrument panel, andless frequently used switches on theoverhead console.

Engine Speed Lock Controller.Enhances operation during long haulcycles by allowing the operator tomaintain a desired engine speed withoutmaintaining pressure on the accelerator.

Simplified Transmission Control.Simplifies gear selection (1st, 2nd,Drive and Reverse) and allowsoperator-defined top gear control.Relocating the gear control to therear increases operator legroom.

9

14

5

3

(Down)

1 (Up)

2 (Forward) 2 (Return)

Cushion Hitch. The electronicallyactuated cushion hitch incorporatesa parallelogram-type linkage forexceptional strength with nitrogenaccumulators to deliver a smooth ridefor enhanced operator comfort.

• controlled oil flow dampens reboundoscillation

• leveling valve automatically centerspiston in cylinder for all loads

• steel castings are used extensivelyto eliminate many welded joints andincrease strength

• double-kingbolt design withstandshigh external forces and simplifiesinstallation and removal

Nitrogen Accumulators. Verticallymounted hydraulic cylinder transfersroad shocks to nitrogen accumulators.Nitrogen accumulators absorb anddampen road shocks, thus reducingthe loads from being transmitted tothe operator.

Lockout Switch. An operator-selectablelockout switch, located on the joystick,locks the cushion hitch for improvedcontrol of the cutting edge duringloading and dumping.

10

StructuresSuperior structural design and construction optimize performance and reliability.

1 Load cylinder 2 Hitch castings 3 Scraper gooseneck 4 Nitrogen accumulators 5 Orifice 6 Oil from tractor hydraulic system 7 Leveling valve 8 Free floating pistons

1

2

3

4

8

4

8

5

6

7

Redesigned Bowl. Excellent productivitywith a 10% increase in bowl capacityfrom the F series, improved draft armprotection, and better load retention.Low-profile design of the bowl offersless resistance to incoming materials,while cellular construction addsstrength and dent resistance to bowlsides and floor.

Bulldozer Ejection System.Combines constant spreading controlwhile minimizing carryback material.The floor of the bowl retracts as theejector moves forward, allowing theoperator to precisely control the flowof material.

Cutting Edges. May be adjusted accordingto job conditions. For most efficientloading, use the thinnest edge thatprovides satisfactory wear life andimpact resistance.

Caterpillar Ground Engaging Tools(G.E.T.). A wide variety of GroundEngaging Tool (GET) options, such asstandard, serrated, and abrasion resistantmaterial (ARM), are available to optimizescraper loading in various materials.Most are reversible to provide long lifeand reduced operating costs. Contactyour Cat Dealer to learn more aboutthe best tools for your applications.

Material Application. The 623G is idealfor windrowing, blending material aswell as breaking up vegetation instripping operations.

11

Scraper BowlDesigned for optimum loading, material retention and ejection.

Versatility. The 623G is ideal forwindrowing, blending material as wellas breaking up vegetation in strippingoperations.

Material Handling. The elevator liftsmaterial off of the cutting edge andcarries it to the top of the elevator andthen dumps the material into the bowl.Blending the material helps eliminatevoids in the bowl for consistent payloadsand even unloading.

Drive Sprockets. Split, bolt-on drivesprockets eliminate the need to removethe chain during servicing and requireno lubrication. Hydraulically adjustablechains have exceptional pull strength fordependable performance and long life.

Throat Opening. Adjustable up to610 mm (24"), enables faster loadingand greater material control.

Low-Maintenance Rollers. Carrier rollersand chain idlers are heat-treated forwear resistance. Fixed elevator rollersrequire no adjustment, reducingmaintenance. Sealed and lubricatedfloor rollers are maintenance free.The direct acting floor mechanismeliminates the drag link.

Two-stage Ejection System. Allows thefloor to slide backward while a dozer-typeejector moves forward (toward thecutting edge), cleaning the entire bowlin one motion.

Implement Pumps. High-pressure,engine-driven implement pumps enablethe operator to take deeper cuts andload in a shorter distance with lesselevator stall.

Elevator Controls. The operator hasvariable control of the elevator to matchthe speed of the elevator to the materialconditions for increased productivity.

Reversible. The elevator reversesfor spreading topsoil, unloadingcohesive material, and blendingwindrowed material.

Single-pivot Design. The single-pivotelevator design improves the loadprofile which allows the machineto achieve consistent payloads.

Chain Adjustment. Maximize chain lifequickly and easily with just a grease gun.

12

Elevator MechanismSelf-loading capability, versatility and excellent material handling characteristics.

Grouped Service Points. Maintenanceand service points for the engine aregrouped on the right-hand side foreasy access. They include the engineair cleaner, engine oil check and fill,fuel filters and priming, coolant levelsight glass, window washer bottle,air conditioning dryer cartridge, etherstarting aid canister, engine oil filter,fan drive lubrication, and samplingports for the engine oil and coolant.

• Spin-on fluid filters for all but themain hydraulic filter

• Cab wiring harness redesigned andrelocated for better serviceability

Electronic Monitoring System (EMS III).Monitors machine status and providesreal-time information to the operatorincluding warnings of problems identifiedby the Electronic Control Modules.

Event Log. The EMS event log recordsproblems detected by the controlsystem, including the time an eventoccurs, the number of occurrencesfor the event, an event identifier andproblem code. The event log canbe accessed using the ElectronicTechnician (Cat ET).

Implement Valve Relocation.The implement valve has been relocatedfrom the tractor to the top of scraperdraft tube, reducing the number of hosesand tubes that cross over the gooseneck.The move reduces potential leak points,and improves service access.

One Piece Power Block. Jumpstartreceptacle and disconnect switchare integrated into a one-piece powerblock for better electrical integrity andserviceability. The disconnect switch,with a lockable cover, disables all powerfrom the batteries and jumpstart functions.

Electro-Hydraulic Implement Control.Simplifies serviceability by removingthe cab pilot valve and associated lines,which also improves reliability andreduces noise. The high efficiencyelectro-hydraulic pilot oil filter providescleaner oil for the pilot system.

Scraper Electrical Harness. A ribbonwiring harness replaced the cableharness for improved wear and durability.Its increased flexibility oscillates with themachine, and polyurethane boots offerbetter protection against the elements.

Access Doors. The tractor has a standardtwo-piece door on the right side forbetter access to service points. The hood,hinged on the front and supported byspring struts, easily opens towards thefront of the machine, for better accessto the top of the engine.

Electronic Technician (Cat ET).The Caterpillar Electronic Technician(Cat ET) Service Tool is useful introubleshooting existing problemsor identifying potential problemsby displaying:

• Real-time pressures, temperatures,fuel settings and diagnosticmessages

• Historical data such as engine over-speeds, overheating, low oil pressureand air filter restriction events

• More detailed information to theservice technician who can accessET via a laptop computer

Easy Access Diagnostics. Diagnosticcodes are accessible through the EMSmain display module, via the Cat ET.Relaying this information to the servicetechnician can let him know which tools,troubleshooting guides, and possiblyeven replacement parts to bring tothe machine.

SAFETY.CAT.COM™.

13

ServiceabilityCount on Caterpillar for simplified service and the most productive uptime.

Product Support. You will find nearlyall parts at our dealer parts counter.Cat dealers use a world-wide computernetwork to find in-stock parts to minimizemachine down time. Save money withgenuine Cat Reman parts. You receivethe same warranty and reliability as newproducts at substantial cost savings.

Machine Selection. Make detailedcomparisons of the machines underconsideration before purchase.Cat dealers can estimate componentlife, preventive maintenance cost,and the true cost of lost production.

Purchase. Look past initial price.Consider the financing options availableas well as day-to-day operating costs.Look at dealer services that can beincluded in the cost of the machineto yield lower equipment owning andoperating costs over the long run.

Customer Support Agreements.Cat dealers offer a variety of productsupport agreements, and work withcustomers to develop a plan that bestmeets specific needs. These plans cancover the entire machine, includingattachments, to help protect thecustomer’s investment.

Operation. Improving operatingtechniques can boost your profits.Your Cat dealer has videotapes, literatureand other ideas to help you increaseproductivity, and Caterpillar offerscertified operator training classes tohelp maximize the return on yourmachine investment.

Maintenance Services. Talk to yourdealer about the range of availablemaintenance services. Repair optionprograms guarantee the cost of repairsup front. Diagnostic programs such asS•O•SSM Analysis and Coolant Samplingand Technical Analysis help avoidunscheduled repairs.

Replacement. Repair, rebuild or replace?Your Cat dealer can help you evaluatethe cost involved so you can make theright choice.

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Customer SupportCat dealer services help you operate longer with lower costs.

15623G Wheel Tractor Scraper specifications

Scraper Bowl

Heaped Capacity 17.5 m3 23 yd3

Rated Load 25 000 kg 55,115 lbStruck Capacity 13.8 m3 18 yd3

Depth of Cut – Max 330 mm 13 inWidth of Cut, to Router Bits 3505 mm 138 inGround Clearance – Max 387 mm 15.2 inCutting Edge Thickness 29 mm 1.14 inHydraulic Penetration Force 150 kN 33,750 lbDepth of Spread – Max 380 mm 15 in

Elevator

Length – Overall 3730 mm 146.9 inWidth of Flight Face 217 mm 8.5 inLength of Flights 2260 mm 89 inSpacing of Flights 510 mm 20 inNumber of Flights 15

Steering

Width – 180° Turn 10.9 m 35.9 ftSteering Angle – Right 90°Steering Angle – Left 85°Hydraulic Output 209 L/min 55 gal/min

• Optional supplemental steering system meets SAE J1511(OCT 90) and ISO 5010 (1992) requirements.

Service Refill Capacities

Fuel Tank 606 L 160 galCrankcase 36 L 9.5 galTransmission 72 L 19 galDifferential 144 L 38 galFinal Drive (each side) 19 L 5 galWheel Coolant (each) 45 L 12 galCooling System 107 L 28 galHydraulic Reservoir 140 L 37 gal

Engine

Tractor Engine Cat C15 with ACERT technology

Net Power – Gears 1-2 246 kW 330 hpNet Power – Gears 3-8 272 kW 365 hpGross Power – Gears 1-2 268 kW 359 hpGross Power – Gears 3-8 294 kW 394 hpBore 140 mm 5.5 inStroke 165 mm 6.5 inDisplacement 15.2 L 928 in3

Flywheel Power 246 kW 330 hp

• Net power advertised is the power available at rated speedof 1,800 rpm, measured at the flywheel when the engine isequipped with fan, air cleaner, muffler and alternator.

Transmission

1 Forward 5 kph 3.1 mph2 Forward 7.6 kph 4.7 mph3 Forward 10.9 kph 6.8 mph4 Forward 14.8 kph 9.2 mph5 Forward 19.9 kph 12.4 mph6 Forward 26.9 kph 16.7 mph7 Forward 36.4 kph 22.6 mph8 Forward 51.5 kph 32 mphReverse 9.2 kph 5.7 mph

Hydraulics

Bowl Cylinder Bore 152 mm 6 inBowl Cylinder Stroke 508 mm 20 inFloor Cylinder Bore 152 mm 6 inFloor Cylinder Stroke 1353 mm 53.25 inEjector Cylinder Bore 127 mm 5 inEjector Cylinder Stroke 1220 mm 48 inSteering Circuit 209 L/min 55 gal/minScraper Circuit 241 L/min 63.7 gal/minCushion Hitch Circuit 37 L/min 9.8 gal/minSupplemental Steering Circuit 150 L/min 39.9 gal/minRelief Valve – Steering Circuit 15 500 kPa 2,250 psiRelief Valve – Implement Circuit 17 300 kPa 2,510 psiCompensator Settings – 16 000 kPa 2,175 psiCushion Hitch CircuitCompensator Settings – 36 175 kPa 5,246 psiElevator Circuit

• Steering circuit at 1,900 rpm.

DimensionsAll dimensions are approximate.

1 Width – Overall Machine 3556 mm 140 in2 Width – Tractor 3130 mm 123.2 in3 Width – Rear Tire Center Lines 2180 mm 85.8 in4 Width – Inside of bowl 2946 mm 116 in5 Width – Outside Rear Tires 3048 mm 120 in6 Height – Overall Shipping 3708 mm 146 in7 Height – Top of Cab 3423 mm 134.8 in

8 Ground Clearance, Tractor 553 mm 21.8 in9 Front of Tractor to Front Axle 3058 mm 120.4 in10 Rim Radius 432 mm 17 in11 Height – Scraper Blade Max. 380 mm 15 in12 Wheelbase 7976 mm 314 in13 Length – Overall Machine 13 209 mm 520 in14 Rear Axle to Rear of Machine 2176 mm 85.7 in

12 3 4 5 6

7

9

11

1213

14

10

8

623G

16 623G Wheel Tractor Scraper specifications

Standards

• Rollover Protective Structure (ROPS) meets SAE J320a,SAE J1040 MAY 94, ISO 3471-1986 and ISO 3471-1994

• Falling Object Protective Structure (FOPS) meets SAE J231JAN 81 and ISO 3449-1992

• The operator sound exposure Leq (equivalent soundpressure level) measured according to the work cycleprocedures specified in ANSI/SAE J1166 OCT98 is 81 dB(A),for cab offered by Caterpillar, when properly installed andmaintained and tested with the doors and windows closed.

• Hearing protection may be needed when operating withan open operator station and cab (when not properlymaintained or doors/windows open) for extended periodsor in noisy environments.

Weights

Total Operating – Empty 37 435 kg 82,530 lbFront Axle 23 958 kg 52,819 lbRear Axle 13 477 kg 29,711 lbTotal Shipping 36 830 kg 81,196 lbTractor Shipping 23 940 kg 52,778 lbScraper Shipping 12 891 kg 28,419 lbTotal Operating – Loaded 62 435 kg 137,646 lbFront Axle Weight – Loaded 31 218 kg 68,823 lbRear Axle Weight – Loaded 31 218 kg 68,823 lb

17623G Wheel Tractor Scraper specifications

Gradeability/Speed/Rimpull

To determine gradeability performance: Read from grossweight down to the percent of total resistance. Total resistanceequals actual percent grade plus 1% for each 9 kg/t (20 lb/ton)of rolling resistance. From this weight-resistance point, readhorizontally to the curve with the highest obtainable gear, thendown to maximum speed. Usable rimpull will depend upontraction available and weight on drive wheels.

0 10 20 30 40 50 60

10

0

20

30

40

0

0

20 40 60 80 100 140120

km/h

mph

kg x 1000

lb x 1000lb x1000

kg x1000

0 5 10 15 20 25 30 35

0

20

40

60

80

10 20 40 50 60 7030

5%

30%

25%

20%

15%

10%

8th Gear

3rd Gear

2nd Gear

1st Gear

5th Gear4th Gear

6th Gear7th Gear

Direct Drive

Torque Converter Drive

E L

623G Tier 3 — RimpullStandard Arrangement*

Gross Weight

Speed

Tota

l Res

ista

nce

(Gra

de p

lus

Rolli

ng R

esis

tanc

e)

Rim

pull

1—1st Gear Torque Converter Drive2—2nd Gear Direct Drive3—3rd Gear Direct Drive4—4th Gear Direct Drive5—5th Gear Direct Drive6—6th Gear Direct Drive7—7th Gear Direct Drive8—8th Gear Direct Drive

* at sea level

E—Empty 36 830 kg (81,196 lb)

L—Loaded 62 135 kg (137,646 lb)

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 km/h

mph

kg x 1000

lb x 1000

25%

30%

5%

10%

15%

20%

0 10 20 30 40 50 60 70 80

0 20 40 60 80 100 120 140 160 180

0 5 10 15 20 25 30 35 40

E L

8th Gear

3rd Gear

5th Gear

4th Gear

6th Gear

7th Gear

Retarding

To determine retarding performance: Read from gross weightdown to the percent effective grade. (Effective grade equalsactual percent grade minus 1% for each 9 kg/t (20 lb/ton) ofrolling resistance). From this weight-effective grade point,read horizontally to the curve with the highest obtainablespeed range, then down to maximum descent speed theretarder can properly handle.

623G Tier 3 — Retarding*Gross Weight

Speed

Effe

ctiv

e G

rade

(Gra

de m

inus

Rol

ling

Resi

stan

ce)

3—3rd Gear Direct Drive4—4th Gear Direct Drive5—5th Gear Direct Drive6—6th Gear Direct Drive7—7th Gear Direct Drive8—8th Gear Direct Drive

* at sea level

E—Empty 36 830 kg (81,196 lb)

L—Loaded 62 135 kg (137,646 lb)

Standard EquipmentStandard equipment may vary. Consult your Caterpillar dealer for details.

POWER TRAINEngine

Electronic Unit Injection (EUI)Electric Start, 24VFan, suctionGround Level Engine ShutdownMufflerStarting Aid, etherThermo-shield, laminatedCat C15, 6-cylinder Diesel with ACERT technologyAir Cleaner, dry-type with pre-cleanerRadiator, NGMR (9 fins per inch)Guard, crankcase

Braking SystemParking/Primary/SecondaryShields – brake

Transmission8-speed Automatic Powershift with Electronic ControlControl Throttle ShiftingDifferential – lockupDownshift InhibitorNeutral Coast InhibitorProgrammable Top-gear Selection

OTHER STANDARD EQUIPMENTAir DryerCushion HitchExtended Life Coolant, –36° C (–33° F)Fast Oil ChangeFendersLocks, vandalism protectionProduct Link readyRims – 29 in (736.6 mm)Tires, 33.25-R29 radialTow Pins – front and rear

ELECTRICALAlarm, backupAlternator, 75 ampBatteries (4), 12V Maintenance Free, High OutputElectrical System, 24VLighting System

Directional SignalsHazard LightsHeadlights, halogen with dimmerFloodlight, cutting edgeLighting System – Scraper

Directional SignalsHazard LightsStop/Tail

Starting Receptacle

OPERATOR ENVIRONMENTAir Conditioner (includes heater and defroster)Cigarette Lighter and AshtrayCoat HookDiagnostic Connection Port (12V)Dome Courtesy LightGauge Group

Air PressureConverter/Retarder TemperatureElectronic Monitoring System (EMS III)Engine Coolant TemperatureActual Transmission Gear IndicatorFuelSpeedometerTachometerTransmission Gear Indicator

HornImplement Control JoystickRearview MirrorsRadio Ready (two radio openings, speakers,

and 5-amp converter)ROPS Cab with Sound Suppression and PressurizationStatic SeatbeltSeat, Air Suspension, Caterpillar Comfort, clothSteering Wheel – tilt and telescopingStorage CompartmentEngine Speed Control LockTransmission HoldWindows – sliding side, swing outWindshield – laminated glassWindshield Wiper/Washer – front and rear

18 623G Wheel Tractor Scraper specifications

19623G Wheel Tractor Scraper specifications

Optional EquipmentOptional equipment may vary. Consult your Caterpillar dealer for details.

kg lbRetarder, hydraulic 150 330Ripper Teeth 290 640Steering, secondary 50 110

kg lbFenders, scraper 121 266Fuel System, fast-fill 10 23Heater, engine coolant 2 4Lights, side vision 5 10

R

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Printed in U.S.A.

Materials and specifications are subject to change without notice.Featured machines in photos may include additional equipment.

See your Caterpillar dealer for available options.

CAT, CATERPILLAR, ACERT, SAFETY.CAT.COM, their respective logos, “Caterpillar Yellow”and the POWER EDGE trade dress, as well as corporate and product identity used

herein, are trademarks of Caterpillar and may not be used without permission.

AEHQ5614-01 (8-07)

Replaces AEHQ5614 (12-04)

623G Wheel Tractor Scraper