Caterpillar 627B
Maintenance schedule, common problems & OEM parts breakdown
The Caterpillar 627B is a heavy-duty wheel tractor-scraper designed for high-productivity earthmoving, including digging, hauling, and leveling topsoil. This twin-engine configuration utilizes Caterpillar 3306 engines, providing 225 hp (167.8 kW) for both the tractor and the scraper bowl. The machine features an overall length of 43.75 ft (13335 mm), a width of 11.33 ft (3453.39 mm), and an operating weight of approximately 76,300 lb (34,609 kg). It is engineered for applications in construction, mining, and agriculture.
Across its production lifespan, the 627B maintained a reputation for reliability through its robust powertrain and specialized twin-engine design. In today's used equipment market, the 627B remains a significant asset due to its availability of heavy-duty components and its proven ability to handle large-scale excavation tasks. Maintenance of the 3306 engine series and the transmission system is critical for preserving resale value and operational uptime in demanding environments.
Below: full specifications, fluids & capacities, the factory service schedule, common service parts, verified fault codes, what owners discuss, attachment guidance, the complete assembly directory, and a serial-number reference. Complete parts lists with full OEM part numbers, exploded diagrams, quantities, and fitment data are available free in Heavy Parts AI.
Caterpillar 627B specifications
Engine
| Tractor Engine Model | 3306 |
| Scraper Engine Model | 3306 |
| Net Power (Tractor/Scraper) | 225 hp (167.8 kW) |
| Power Measured @ | 2100 rpm |
| Displacement (Tractor/Scraper) | 638 cu in (10.5 L / 10,455 cc) |
Weights
| Total Operating Weight - Empty | 76,200 lb (34,563.8 kg / 34,564 kg) |
Dimensions
| Overall Length | 13,335 mm (43.75 ft) |
| Overall Width | 3,453.39 mm (11.33 ft) |
| Overall Height | 3,627.12 mm (11.9 ft / 4 m) |
| Wheelbase | 7,720.59 mm (25.33 ft / 8 m) |
Performance
| Max Speed Forward | 34 mph (54.8 km/h / 55 km/h) |
| Heaped Bowl Capacity | 15.3 m³ (20 yd³ / 15 m³) |
| Struck Bowl Capacity | 10.8 m³ (14 yd³ / 11 m³) |
| Width of Cut | 3,025 mm (10 ft / 3 m) |
| Max Depth of Cut | 340 mm (13.4 in / 34 cm) |
| Tire Size | 29.5x29, 28PR |
Service capacities (summary)
| Fuel Capacity | 1,003.2 L (265 gal / 1,003 l) |
Values vary by configuration, region, and serial range — confirm against your machine before planning transport or lifts.
627B fluids & capacities
| System | Capacity | Recommended fluid |
|---|---|---|
| Engine Crankcase | Not specified | Cat DEO (Diesel Engine Oil) SAE 15W-40 or SAE 10W-30; use Cat DEO-ULS for ECF-3 / API CJ-4 requirements; use Cat DEO-ULS Cold Weather for extreme temperatures (SAE 0W-40). Engine model identified as 3306 twin engines. |
| Hydraulic System and Tank | Not specified | Cat HYDO Advanced Oils; use bio-based hydraulic fluid to optimize drain intervals in hot climates. |
| Transmission/Powertrain | Not specified | Cat TDTO (Transmission/Drive Train Oil). |
| Grease | Not specified | Varies by application: Cat Multipurpose Grease (low-load/low-speed); Cat Advanced 3Moly Grease (medium-load/medium-speed); Cat Ultra 5Moly Grease (high-load/high-speed); Cat Desert Gold Grease (hot-weather); Cat Arctic Platinum Grease (cold-weather). |
Capacities are refill values from factory literature — always fill to the dipstick/sight gauge, not the number.
Caterpillar 627B maintenance schedule
| Service interval | Tasks |
|---|---|
| Every 10 h |
|
| Every 250 h |
|
| Every 500 h |
|
| Every 1,000 h |
|
| Every 2,000 h |
|
Servicing the 627B beyond the schedule
Predictive Maintenance & Fluid Analysis
Utilize Caterpillar S.O.S Services to monitor engine oil, hydraulic fluid, and coolant. Analyze engine oil for wear metals like iron or copper and check for silicon from dirt ingestion. Monitor hydraulic oil particle counts (ISO cleanliness) and viscosity changes to prevent pump failure. Regular coolant analysis detects pH shifts or SCA depletion, preventing internal liner pitting and overheating in the 3306 engines.
Corrective & Common Repairs
Address transmission slipping by inspecting top covers, slides, and valves for wear. Monitor the 3306 tractor engine for injector or flywheel issues if power loss occurs during heavy climbs. Inspect hydraulic hoses regularly for abrasions or cracks to prevent high-pressure leaks that cause pump cavitation. Ensure all pins and bushings are lubricated to prevent structural play in the scraper bowl and hitch assemblies.
Overhaul & Rebuild Points
Plan major rebuild points around the 2,000-hour PM4 interval. Focus on comprehensive structural inspections of welds and the transmission system overhaul. Evaluate the condition of the turbocharger and final drive components for replacement. When rebuilding the twin-engine setup, verify all engine mounts and hydraulic system seals to ensure the integrity of the 3306 power units and the overall scraper bowl operation.
Seasonal & Environment Servicing
In dusty or quarry environments, check air filters daily and clean radiator fins frequently to prevent overheating. For high-load operations in hot climates, consider shortening engine oil intervals to 200 hours. During cold weather operation, utilize appropriate lubricants and inspect battery condition and heater functionality. Ensure the scraper bowl is cleared of debris to maintain efficient cutting depth and prevent material buildup.
627B fault codes & troubleshooting
| Code | Meaning | Likely cause | What to do |
|---|---|---|---|
| 110-0 | Engine Coolant Temperature — Above Normal | Low coolant level or thermostat failure | Inspect cooling system and refill coolant |
| 110-3 | Engine Coolant Temperature Sensor — Voltage High | Open circuit or sensor failure | Check wiring and replace sensor if faulty |
| 174-3 | Engine Fuel Temperature — Voltage Above Normal | Open circuit in sensor wiring | Inspect harness and replace sensor if necessary |
| 190-8 | Engine Speed — Abnormal Frequency | Speed sensor air gap, sensor failure, or tone ring damage | Check sensor gap and test speed sensor/tone ring |
| 41-3 | 8-Volt DC Supply — Voltage Above Normal | Short to power on 8V reference circuit | Inspect sensors sharing the 8V supply and isolate fault |
| 41-4 | 8-Volt DC Supply — Voltage Below Normal | Short to ground on 8V reference circuit | Disconnect sensors one at a time to locate short |
| E360 | Engine Coolant Temperature — High | Low coolant, failed thermostat, or water pump issue | Diagnose cooling system; do not operate until resolved |
| E361 | Engine Coolant Temperature — Very High (Shutdown) | Severe cooling system failure | Perform full cooling system diagnosis; engine shutdown required |
Codes and remedies are general guidance for this model family — always confirm with diagnostic tooling and your dealer before major repairs.
627B attachments & work tools
Bowl Attachments
Open bowl configurations feature a heaped capacity of 20 yd³ (15 m³) and a struck capacity of 14 yd³ (11 m³). The cutting width is 10 ft (3 m) with a maximum depth of cut of 13 in (34 cm).
Mounting & Hitch Systems
The machine utilizes a cushion hitch configuration. Some units are identified as twin engine scrapers.
Hydraulic & Technology Options
Cat Grade attachment is an optional tool that provides intelligent grade control to prevent overfilling or cutting below grade. The tractor includes a hydraulic on-demand fan for fuel efficiency optimization.
Protection & Guarding
Draft-arm overflow guards are available to divert material away from the bowl and prevent accumulation between draft arms and bowl sides. Operator environments may include EROPS or OROPS cab configurations.
All 627B assemblies by section
Every catalogued assembly group for the Caterpillar 627B. Open an assembly to preview the parts inside — full OEM part numbers are available in Heavy Parts AI.
Air Inlet And Exhaust System
219-9711 Turbocharger Gp
| 21***11 | Turbocharger Group | 1 |
Basic Engine
9n-5760 Damper Gp
| 9N***60 | Damper Group | 1 |
284-7810 Kit-Hardware
| 28***10 | Kit-Hardware | 1 |
Engine Arrangement
279-3380 Conversion Ar-Engine
| 27***80 | Conversion Ar-Engine | 1 |
279-3379 Conversion Ar-Engine
| 27***79 | Conversion Ar-Engine | 1 |
Fuel System
7c-8993 Fastener Gp-Fuel Inj Pump
| 7C***93 | Fastener Group-Fuel Inj Pump | 1 |
111-5162 Control Gp-Fuel Ratio
| 11***62 | Control Group-Fuel Ratio (Basic) | 1 |
1w-7834 Governor Gp
| 1W***34 | Governor Group | 1 |
4p-9827 Pump Gp-Fuel Injection
| 4P***27 | Pump Group-Fuel Injection | 1 |
111-3769 Pump Gp-Fuel Injection
| 11***69 | Pump Group-Fuel Injection | 1 |
7c-8992 Seal Gp-Pump
| 7C***92 | Seal Group; -Fuel | 1 |
8n-7276 Torque Control Gp
| 8N***76 | Torque Control Group | 1 |
Service Equipment And Supplies
279-3374 Kit-Engine Parts
| 27***74 | Kit-Engine Parts | 1 |
279-3373 Kit-Engine Parts
| 27***73 | Kit-Engine Parts | 1 |
627B serial number reference
The PIN plate is a durable metal identification plate usually riveted to the machine frame. To read the prefix, locate the first three alphanumeric characters of the serial number; these identify the model and manufacturing factory.
| Prefix | Identifies | Notes |
|---|---|---|
| 14S | 627B (US) | Twin engine scraper with cushion hitch and powershift transmission. Engine: 3306 twin engines, 225 hp (167.8 kW) @ 2100 rpm, 638 cu in (10.5 L) displacement. Max forward speed: 34 MPH (54.7 km/h). Bowl capacity: 20 cu yd (15 cu m) heaped / 14 cu yd (11 cu m) struck. Cutting width: 10 ft (3 m). Max depth of cut: 13 in (34 cm). Weight: 76300 lbs (34611 kg). Standard tires: 29.5x29 29PR. |
| 15S | 627B (US) | Twin engine scraper with cushion hitch and powershift transmission. Engine: 3306 twin engines, 225 hp (167.8 kW) @ 2100 rpm, 638 cu in (10.5 L) displacement. Max forward speed: 34 MPH (54.7 km/h). Bowl capacity: 20 cu yd (15 cu m) heaped / 14 cu yd (11 cu m) struck. Cutting width: 10 ft (3 m). Max depth of cut: 13 in (34 cm). Weight: 76300 lbs (34611 kg). Standard tires: 29.5x29 29PR. |
Frequently asked questions
What engine powers the Caterpillar 627B?
The 627B utilizes Caterpillar 3306 engines for both the tractor and the scraper, delivering 225 hp (167.8 kW) each.
What is the standard operating weight of this machine?
The standard operating weight for a Caterpillar 627B scraper is approximately 34,609 kg (76,300 lb).
What model replaced the 627B?
Information regarding the specific direct successor to the 627B is not documented in the provided technical sources.
What 627B owners discuss
What are the common symptoms of transmission issues in a 627B when operating on inclines?
What engine configuration is standard for the Caterpillar 627B tractor?
What are the primary causes of power loss or engine performance degradation in these machines?
What should be monitored regarding the hydraulic system to prevent component failure?
What electrical issues are frequently reported in Caterpillar heavy equipment?
What is the most critical item to inspect when purchasing a used 627B scraper?
Compiled from owner and technician discussions across the industry — experiences vary by serial range and machine history.
Serial-range & configuration variants
This page covers the Caterpillar 627B. Related factory variants of the same model family:
Need a specific 627B part?
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