Caterpillarpaving compactorvibratory compactor
Caterpillar CB-634
Maintenance schedule, common problems & OEM parts breakdown
The Caterpillar CB-634 is a tandem, double-drum vibratory asphalt compactor in the roughly 12.2-12.8 tonne (26,900-28,200 lb) operating class, built for intermediate and finish rolling on asphalt paving work. Across the documented B, C and D updates the machine runs Caterpillar's 3116T turbocharged diesel inline-six, rated around 108 kW (145 hp) gross and 103 kW (138 hp) net; documentation for the earliest base CB-634 is thin online, so confirm the engine on any pre-B unit against the build plate. Production ran from roughly the late 1980s (as the original CB-634 and CB-634B) through a 1990s C-series and into a mid-2000s D-series before Caterpillar retired the designation. It followed earlier double-drum vibratory rollers in Cat's combination-roller family and has no single named successor of its own; the equivalent weight class today is covered by Cat's newer CB13 and CB15 tandem vibratory rollers. Caterpillar offered the CB-634 with either an open ROPS canopy or an enclosed, air-conditioned cab, 2134 mm (84 in) smooth double drums, and a water spray system for asphalt release.
Changes across the B, C and D updates read as incremental rather than a shift in size or power class: available parts and dealer documentation point to refined engine controls, instrumentation and cab ergonomics rather than a different drum package, and published specs for the C and D series fall in the same power and weight range. That continuity is a large part of why the CB-634 still matters in the used and parts market: its 3116T engine and hydrostatic drum driveline are shared with other Caterpillar compactors from the same era, so engine, hydraulic and drum-bearing components stay easier to source than on a one-off design. Paving contractors and municipal fleets still running older CB-634 units value them as low-cost, mechanically simple finish rollers, and the model's long production run left a healthy population of used machines and rebuildable components in circulation well after Caterpillar stopped building new ones.
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 CB-634 specifications
Engine
| Engine model | Cat 3116T turbocharged diesel, inline-6 (this engine family is documented across CB-634 series compactors; series-specific tuning may vary) |
| Gross power | 108 kW (145 hp) at 2,200 rpm |
| Net power | 103 kW (138 hp) at 2,200 rpm |
| Displacement | 6.6 L / 402.8 cu in (6,600 cm3), 6 cylinders |
| Aspiration | Turbocharged, rated to operate at altitude up to 2,500 m (8,200 ft) without derating |
| Emissions tier | Not published in available spec sheets for this model — verify with dealer for the exact serial/series range |
Weights
| Operating weight (D-series) | 12,800 kg (28,219 lb) |
| Operating weight (earlier series, per some spec listings) | 12,210 kg (26,920 lb) — varies by series/configuration |
| Shipping weight | Not published in available spec sheets |
| Ground pressure | Not published in available spec sheets |
Dimensions
| Overall length | 4.95 m (16 ft 3 in) |
| Overall width | 2.32 m (7 ft 7 in) |
| Overall height (top of cab/ROPS) | 3.11-3.17 m (10 ft 2 in - 10 ft 4 in), figure varies slightly by source/series |
| Drum width | 2,130 mm (84 in) |
| Inside turning radius | 4.32 m (170 in) |
| Wheelbase / ground clearance | Not published in available spec sheets |
Performance
| Maximum travel speed | 12.2 km/h (7.6 mph) |
| Vibration frequency | 2,520 vpm (approx. 42 Hz), per base-series listing |
| Gradeability | Not published in available spec sheets |
Service capacities (summary)
| Fuel tank | 250 L (66.1 gal) |
| Hydraulic system | 60.2 L (15.9 gal) |
| Engine oil | 17 L (4.5 gal) |
| Cooling system | 31 L (8.2 gal) |
Values vary by configuration, region, and serial range — confirm against your machine before planning transport or lifts.
CB-634 fluids & capacities
| System | Capacity | Recommended fluid |
|---|---|---|
| Engine crankcase (Cat 3116T turbocharged diesel, 6-cyl, 6.6 L displacement, with filter) | 17 L (4.5 US gal) | Cat DEO (Diesel Engine Oil). Viscosity by ambient temperature per Cat factory guidance: SAE 10W-30 for roughly -20C to 40C (-4F to 104F), SAE 15W-40 for roughly -15C to 50C (5F to 122F) in warmer climates, and full-synthetic 0W-40/5W-40 grades for sustained cold below -20C (-4F). Confirm exact break points against the climate chart in the machine's own OMM. |
| Cooling system | 31 L (8.2 US gal) | Cat ELC (Extended Life Coolant), premixed or concentrate mixed to a 50/50 water-glycol ratio; Cat DEAC accepted where ELC is unavailable. Use extended-life coolant extender at mid-life interval if running ELC. |
| Fuel tank | 250 L (66 US gal) | Ultra-low-sulfur No. 2-D diesel meeting Cat engine fuel specification; no lubricant brand applies to this compartment. |
| Vibratory drum bearing lubrication (oil-bath eccentric weight housings, front and rear drum combined) | 11 L (2.9 US gal) | Cat GO (Gear Oil), SAE 85W-140 for general service, SAE 80W-90 in cooler ambient conditions. This compartment uses standard Cat GO, not the dedicated Cat Compactor Oil product line, which Caterpillar reserves for 500-series single-drum soil compactors and mining-shovel swing/travel gearboxes. |
| Transmission / propel drive | No separate compartment listed. Hydrostatic propel (variable-displacement piston pump driving two-speed motors through drum planetary gearboxes) draws from the common hydraulic reservoir. | Same fluid as hydraulic tank (Cat HYDO or Cat TDTO, see hydraulic system row); the OMM does not break out an independent transmission oil fill or capacity for this machine. |
| Final drives (drum planetary gearboxes, each drum) | Not separately listed in factory refill data; drive gearboxes are integral to the drum/motor assembly and are not called out with their own service fill on the CB-634D spec sheet. | Not applicable as a standalone compartment for this model; lubrication is bound up with the vibratory bearing oil-bath and hydraulic circuit noted above. Verify against the specific OMM for the machine's serial range. |
| Hydraulic system and tank (propel, steering, vibratory, brake release circuits combined) | 60 L (15 US gal) at tank full-mark; total system capacity including lines and cylinders runs higher than the tank figure. System is protected by a 10-micron charge oil filter. | Cat HYDO (Hydraulic Oil), typically the 10W grade for roughly -20C to 40C (-4F to 104F) ambient. Cat TDTO, Cat Arctic TDTO, or Cat MTO are Caterpillar-approved alternates where a different viscosity is needed for climate or where dealer guidance calls for a shared hydrostatic/hydraulic fluid. |
| Axles / differentials | Not applicable. | Not applicable. The CB-634D propels through hydraulic motor-driven drum planetary gearboxes rather than conventional axle differentials, so this compartment does not exist on the machine. |
| Grease (chassis, articulation pins, drum/eccentric bearings, linkages) | Spec only, no reservoir capacity. | Cat multipurpose grease, NLGI Grade 2, lithium-complex with extreme-pressure additive, for normal ambient service. Cat Ultra 5Moly or equivalent moly-fortified grease for heavily loaded pivot pins. Drop to NLGI Grade 1 or an arctic-grade grease in sustained sub-freezing conditions per the climate note in the lubrication chart. |
| Drum water spray system (not a lubricant; listed in the OMM refill table) | 2 x 600 L (2 x 158.5 US gal), one tank per drum | Plain water. Optional freeze-protection kit allows antifreeze to be pumped through pumps, lines, filters and nozzles for overnight cold-weather protection; not a lubricant specification. |
Capacities are refill values from factory literature — always fill to the dipstick/sight gauge, not the number.
Caterpillar CB-634 maintenance schedule
| Service interval | Tasks |
|---|---|
| Every 10 h |
|
| Every 250 h |
|
| Every 500 h |
|
| Every 1,000 h |
|
| Every 2,000 h |
|
| Every 3,000 h |
|
Servicing the CB-634 beyond the schedule
Predictive Maintenance & Fluid Analysis
Run S.O.S sampling on the 3116T engine oil, hydraulic oil, and both drum bearing housings on a fixed schedule rather than waiting for symptoms — the turbocharger and hydrostatic propel motors on this machine are costly to run to failure. Track coolant condition for scale and inhibitor level, and log vibratory exciter bearing temperature and oil clarity at every drum service. Trend fuel filter restriction and hydraulic case-drain flow to catch pump wear before it strands the roller mid-shift.
Corrective & Common Repairs
Clogged water spray nozzles and worn drum scrapers are the most common asphalt-pickup complaints on the CB-634 — clean or replace them before blaming the spray pump. Hydrostatic propel and vibratory drive motor seals weep with age and cause slow drift or lost vibration on one drum; check case-drain flow before swapping a motor. The 3116T's turbocharger and injectors are the usual high-hour engine repairs, and articulation hitch pins wear oval on machines that see tight-radius work.
Overhaul & Rebuild Points
Vibratory exciter bearings and seals are the core rebuild item on CB-634 drums; plan a teardown once S.O.S shows metal in the drum bearing oil rather than waiting for audible bearing noise. Hydrostatic propel and drum drive motors are candidates for exchange rebuild at high hours, and the 3116T typically needs a turbocharger and injector refresh before a full inline-six overhaul. Drum shells and scraper mounts wear thin on machines with heavy chip-seal or milling-edge work — check shell thickness before committing to a rebuild.
Seasonal & Environment Servicing
Drain the water spray tank, pump, and lines completely before freezing weather — a cracked spray pump or split line is a common winter-storage failure on this compactor. Check coolant freeze-point concentration each fall, since most CB-634 units run conventional coolant in the 3116T rather than long-life fluid. Clear asphalt dust and tack buildup from the radiator and hydraulic oil cooler fins each paving season, and flush drum bearing housings more often on wash-down or pressure-cleaned jobs, since water intrusion is the top cause of early bearing failure.
CB-634 common service parts
| Part number | Part | Notes | |
|---|---|---|---|
| 101-7664 | Film | Lubrication service | Check fitment → |
| 4P-8681 | Film Identification | Lubrication service | Check fitment → |
Always confirm against your machine's serial number — cross-check any part in Heavy Parts AI before ordering.
CB-634 fault codes & troubleshooting
| Code | Meaning | Likely cause | What to do |
|---|---|---|---|
| Engine Oil Pressure warning lamp (red) with audible alarm | Engine oil pressure has dropped below the safe operating threshold | Low oil level, failed oil pressure sending unit/switch, worn oil pump, or clogged oil filter | Idle down and stop the engine immediately, check oil level and filter condition, and inspect the sender and wiring before restarting |
| Engine Coolant Temperature warning lamp with audible alarm | Engine coolant temperature has exceeded the safe operating range | Low coolant level, blocked radiator core or screen, failed thermostat, or slipping/failed fan drive | Reduce load and idle the engine, check coolant level and radiator for debris, and verify fan drive and belt operation |
| Charging System (alternator) warning lamp | Charging circuit is not producing adequate voltage to the batteries | Worn or failed alternator, broken or slipping drive belt, or loose/corroded battery and wiring connections | Check belt tension and condition, inspect battery terminals and charging wiring, and test alternator output |
| Parking/Drum Brake indicator lamp | Parking or drum brake is applied | Brake switch engaged, or brake release solenoid/hydraulic release pressure not releasing the brake | Confirm brake switch position; if the lamp stays lit with the brake released, check the release solenoid and hydraulic release circuit |
| Propel Neutral indicator lamp | Confirms the propel control lever is centered in neutral, which is required by the start interlock | Propel lever out of adjustment or a faulty neutral-start switch | Verify lever centering and adjust or test the neutral-start switch if the engine will not crank with the lever centered |
| Vibratory System indicator lamp | Status indicator showing the selected vibration mode/drum state; not itself a fault code | If the lamp state does not match the selected mode, suspect the vibratory mode selector switch, control solenoid, or related wiring | Cycle the mode selector and confirm switch operation; check the vibratory solenoid and harness if the lamp disagrees with the selected setting |
| Air Filter Restriction indicator | Intake air filter restriction has exceeded the allowable limit | Clogged primary air filter element | Service or replace the air filter element and reset the restriction indicator |
| Hydraulic Oil Temperature warning lamp | Hydraulic system oil temperature has exceeded the safe operating limit | Low hydraulic fluid level, blocked oil cooler core, or a failed cooling fan | Idle the machine to allow cooling, check hydraulic fluid level, and inspect the oil cooler core for debris |
Codes and remedies are general guidance for this model family — always confirm with diagnostic tooling and your dealer before major repairs.
CB-634 attachments & work tools
Drum / roller body
CB-634 (through the C and D series) is a fixed smooth-steel double-drum tandem asphalt roller, drum width roughly 2130-2160 mm (84-85 in) per drum and drum diameter near 1300 mm (51 in). No interchangeable pad-foot, sheepsfoot, or segmented shells are offered for this asphalt-tandem class; the drum is a machined steel unit intended for smooth-mat finishing.
Vibratory exciter settings
Each drum carries a single eccentric exciter with a factory console offering multiple amplitude/frequency selections (documented as up to five steps: High, Medium-High, Medium, Medium-Low, Low). Nominal amplitude runs near 2.5 mm (0.1 in) across settings at about 44 Hz (2640 vpm), with centrifugal force varying roughly 58-159 kN (13,000-35,700 lbf) by setting. This is a built-in operating mode, not a bolt-on attachment.
Water spray / sprinkler system
Drum-mounted water spray bars are standard equipment on the CB-634/CB-634C/CB-634D to keep asphalt from sticking to the drums. Spec sheets list this as base equipment rather than a dealer-installed option, and no separate release-agent or emulsion sprinkler kit is documented specifically for this model.
Operator protection: canopy vs. cab
Base configuration ships with an open ROPS (OROPS) canopy. Caterpillar's general retrofit line offers glass-panel cab-enclosure kits plus heater/air-conditioning add-ons for compactor-class ROPS structures, but no CB-634-specific factory enclosed-cab option is documented in the available spec literature; confirm cab-conversion fitment with a dealer before ordering.
Edge cutting / trimming devices
Later Cat tandem vibratory rollers (CB8 through CB16) offer optional edge-cutter wheels, including a plain cutting wheel and a 45-degree bevel wheel, controlled from the propel lever. This option is documented for the current CB-series and is not confirmed in factory literature for the older CB-634/CB-634D generation; treat as not verified for this model.
Coupler / mounting system
As a self-contained tandem roller, the CB-634 has no quick-coupler, three-point hitch, or PTO mount for interchangeable work tools. The drum, exciter, and spray-bar assemblies are integrated components rather than field-swappable attachments, unlike loader or excavator-class carriers.
Powertrain and hydraulic-kit sizing
The CB-634 line (including CB-634C and CB-634D) is powered by the Caterpillar 3116T turbocharged diesel, rated near 108 kW (145 hp) gross and 103 kW (138 hp) net. Hydraulic system capacity is documented near 60 L (15.9 gal). Any propel- or vibratory-circuit hydraulic kit must be matched to this 3116T-based system rather than to later CB-series machines that use different Cat engine families.
Ballast / weight class
Operating weight is documented in a range of roughly 12,200-12,800 kg (26,900-28,200 lb) depending on source and canopy/ballast configuration, placing the CB-634 in the 12-13 tonne tandem asphalt-roller class. No separate factory ballast-weight kit is documented for this model.
All CB-634 assemblies by section
Every catalogued assembly group for the Caterpillar CB-634. Open an assembly to preview the parts inside — full OEM part numbers are available in Heavy Parts AI.
Air Inlet And Exhaust System
6i2551 Air Cleaner Gp
| 6I***51 | Air Cleaner Group | 1 |
1065584 Air Cleaner Gp
| 10***84 | Air Cleaner Group | 1 |
3f0539 Cap-Air Stack
| 3F***39 | Cap-Air Cleaner | 1 |
4p4686 Cartridge Gp-Turbocharger*R
| 4P***86 | Cartridge Group-Turbocharger | 1 |
1n4877 Cover Gp-Inlet Manifold
| 1N***77 | Cover Group-Inlet Manifold | 1 |
1w6029 Lines Gp-Air
| 1W***29 | Lines Group-Air | 1 |
7w9248 Manifold Gp-Exhaust
| 7W***48 | Manifold Group-Exhaust; Exhaust Manifold Group | 1 |
4w3480 Manifold Gp-Inlet
| 4W***80 | Manifold Group-Inlet; Inlet Manifold Group | 1 |
7c7881 Mounting Gp-Filter
| 7C***81 | Mounting Group-Engine Oil Filter | 1 |
1139489 Muffler Gp
| 11***89 | Muffler Group | 1 |
1125037 Muffler Gp
| 11***37 | Muffler Group | 1 |
4p6171 Turbocharger Gp
| 4P***71 | Turbocharger Group | 1 |
6i2293 Turbocharger Gp*R
| 6I***93 | Turbocharger Group | 1 |
Basic Engine
7c5467 Adapter Gp-Fan
| 7C***67 | Adapter Group-Fan | 1 |
2w9608 Camshaft Gp-Single
| 2W***08 | Camshaft Group-Single | 1 |
4w3462 Carrier Gp-Seal
| 4W***62 | Carrier Group-Seal; Carrier Group (Seal) | 1 |
1051699 Cover Gp
| 10***99 | Cover Group-Cylinder Block | 1 |
7l0004 Cover Gp-Front
| 7L***04 | Cover Group-Front; (Front Housing) | 1 |
4w2172 Cover Gp-Valve Mechanism
| 4W***72 | Cover Group-Valve Mechanism; Valve Mechanism Cover Group | 1 |
4w2197 Crankshaft Gp
| 4W***97 | Crankshaft Group; Crankshaft Group | 1 |
2w9746 Cylinder Block Gp*R
| 2W***46 | Cylinder Block Group | 1 |
1004948 Cylinder Block Gp
| 10***48 | Cylinder Block Group | 1 |
7c5826 Cylinder Block Gp
| 7C***26 | Cylinder Block Group | 1 |
1291095 Cylinder Block Gp
| 12***95 | Cylinder Block Group | 1 |
9y6166 Cylinder Head As*R
| 9Y***66 | Cylinder Head As | 1 |
1154107 Cylinder Head As
| 11***07 | Cylinder Head As | 1 |
1154108 Cylinder Head As
| 11***08 | Cylinder Head As | 1 |
9y8850 Cylinder Head Gp*R
| 9Y***50 | Cylinder Head Group | 1 |
9y8871 Cylinder Head Gp
| 9Y***71 | Cylinder Head Group | 1 |
1154165 Cylinder Head Gp*R
| 11***65 | Cylinder Head Group | 1 |
7c2428 Damper & Pulley Gp
| 7C***28 | Damper & Pulley Group; Damper And Pulley Group | 1 |
7c4532 Drain Gp-Oil Pan
| 7C***32 | Drain Group-Oil Pan; Oil Pan Drain Group | 1 |
7c4566 Drain Gp-Oil Pan
| 7C***66 | Drain Group-Oil Pan; -Magnetic Plug | 1 |
7c0044 Drive Gp-Fan
| 7C***44 | Drive Group-Fan; Fan Drive Group | 1 |
9y2755 Flywheel Gp
| 9Y***55 | Flywheel Group | 1 |
1154175 Gear Gp-Front
| 11***75 | Gear Group-Front | 1 |
2w8475 Gear Gp-Front
| 2W***75 | Gear Group-Front; Front Gear Group | 1 |
9y4856 Housing Gp-Flywheel
| 9Y***56 | Housing Group-Flywheel | 1 |
7l0002 Housing Gp-Front
| 7L***02 | Housing Group-Front | 1 |
1052250 Installation Ar-Engine
| 10***50 | Installation Ar | 1 |
| 10***80 | Mounting Group-Engine Flexible | 1 |
| 10***84 | Lines Group-Fuel | 1 |
1226071 Installation Ar-Engine
| 10***84 | Lines Group-Fuel | 1 |
| 10***56 | Drive Group-Pump | 1 |
| 10***84 | Air Cleaner Group | 1 |
4w2515 Lifting Gp
| 4W***15 | Lifting Group | 1 |
1052380 Mounting Gp-Engine-Flexible
| 10***80 | Mounting Group-Engine Flexible | 1 |
1222275 Mounting Gp-Engine-Flexible
| 12***75 | Mounting Group-Engine Flexible | 1 |
1077571 Pan Gp-Oil
| 10***71 | Pan Group-Oil | 1 |
4w0269 Pan Gp-Oil
| 4W***69 | Pan Group-Oil; -Engine | 1 |
1085758 Piston & Rod Gp-17.0 : 1 Ratio
| 10***58 | Piston & Rod Group | 1 |
1154084 Piston & Rod Gp-17.0 : 1 Ratio
| 11***84 | Piston & Rod Group | 1 |
7e3579 Piston & Rod Gp-16.5 : 1 Ratio
| 7E***79 | Piston & Rod Group | 1 |
4w5429 Pulley Gp-Crankshaft
| 4W***29 | Pulley Group-Crankshaft; Crankshaft Pulley Group | 1 |
1077722 Rocker Arm Gp-Valve
| 10***22 | Rocker Arm Group-Valve | 1 |
4w1016 Seal Gp-Crankshaft
| 4W***16 | Seal Group-Crankshaft | 1 |
4p4372 Valve Mechanism Gp
| 4P***72 | Valve Mechanism Group | 1 |
Braking System
1052400 Lines Gp-Brake-Part 1 Of 2
| 10***00 | Lines Group-Brake | 1 |
1141601 Lines Gp-Brake-Part 1 Of 2
| 11***01 | Lines Group-Brake | 1 |
1052400 Lines Gp-Brake-Part 2 Of 2
| 10***00 | Lines Group-Brake | 1 |
1195761 Lines Gp-Brake-Part 2 Of 2
| 11***61 | Lines Group-Brake | 1 |
1141601 Lines Gp-Brake-Part 2 Of 2
| 11***01 | Lines Group-Brake | 1 |
1195761 Lines Gp-Brake-Part 1 Of 2
| 11***61 | Lines Group-Brake | 1 |
1158488 Pump Gp-Hand
| 11***88 | Pump Group-Brake; -Parking Brake Release | 1 |
1195762 Pump Gp-Brake
| 11***62 | Pump Group-Brake | 1 |
1052401 Valve Gp-Brake
| 10***01 | Valve Group-Brake | 1 |
1141597 Valve Gp-Brake
| 11***97 | Valve Group-Brake | 1 |
1196227 Valve Gp-Brake
| 11***27 | Valve Group-Brake | 1 |
1127040 Valve Gp-Brake/Shift
| 11***40 | Valve Group-Brake & Shift | 1 |
1g9759 Valve Gp-Brake/Shift
| 1G***59 | Valve Group-Brake & Shift | 1 |
Cooling System
4w2913 Cooler Gp-Engine Oil
| 4W***13 | Cooler Group-Engine Oil | 1 |
1231207 Cooling Gp-Supplemental
| 11***32 | Plate | 2 |
| 12***37 | Door As-Rh | 1 |
| 12***88 | Shroud As | 1 |
1308046 Cooling Gp-Supplemental
| 10***66 | Plate | 1 |
| 12***27 | Radiator Group | 1 |
| 12***28 | Mount As | 1 |
4w5428 Drive Gp-Water Pump
| 4W***28 | Drive Group-Water Pump; Water Pump Drive Group | 1 |
1219533 Fan Gp-Blower
| 12***33 | Fan Group-Blower | 1 |
1099710 Fan Gp-Blower
| 10***10 | Fan Group-Blower | 1 |
4w6620 Lines Gp-Water
| 4W***20 | Lines Group-Water | 1 |
4w7589 Pump Gp-Water
| 4W***89 | Pump Group-Water | 1 |
7c4508 Pump Gp-Water*R
| 7C***08 | Pump Group-Water | 1 |
1219534 Radiator & Oil Cooler Gp
| 12***34 | Radiator & Oil Cooler Group | 1 |
1098907 Radiator & Oil Cooler Gp
| 10***07 | Radiator & Oil Cooler Group | 1 |
Electrical System
9w3043 Alternator Gp-Charging*R
| 9W***43 | Alternator Group-Charging; (24-Volt, 52-Ampere) | 1 |
1073327 Alternator Gp-Charging
| 10***27 | Alternator Group-Charging | 1 |
1052405 Battery & Wiring Gp
| 10***05 | Battery & Wiring Group | 1 |
1052254 Electrical Ar
| 10***54 | Electrical Ar | 1 |
| 10***04 | Wiring Group | 1 |
| 10***05 | Battery & Wiring Group | 1 |
1g9876 Horn Gp-Electric
| 1G***76 | Horn Group-Electric | 1 |
813688 Lamp Gp
| 08***88 | Lamp Group; -Front | 1 |
1081621 Lamp Gp-Flood
| 10***21 | Lamp Group-Flood | 1 |
1119714 Lamp Gp-Head
| 11***14 | Lamp Group-Head | 1 |
1119713 Lamp Gp-Signal
| 11***13 | Lamp Group-Signal | 1 |
1119712 Lamp Gp-Signal
| 11***12 | Lamp Group-Signal | 1 |
1119711 Lamp Gp-Signal
| 11***11 | Lamp Group-Signal | 1 |
1061162 Light Gp-Working
| 10***62 | Lighting Group-Flood | 1 |
1175673 Lighting Gp
| 11***73 | Lighting Group-Functional | 1 |
1061161 Lighting Gp-Roading-Part 2 Of 2
| 10***61 | Lighting Group-Roading | 1 |
1061161 Lighting Gp-Roading-Part 1 Of 2
| 10***61 | Lighting Group-Roading | 1 |
1352929 Lighting Gp-Warning
| 13***29 | Lighting Group-Warning; -Engine Temperature | 1 |
1175674 Lighting Gp-Warning
| 11***74 | Lighting Group-Warning | 1 |
7c3729 Pulley-Alternator
| 7C***29 | Pulley-Alternator | 1 |
7c4028 Solenoid Gp-Shutoff
| 7C***28 | Solenoid Group-Shutoff | 1 |
1083858 Starting Motor Gp-Electric
| 10***58 | Starting Motor Group-Electric | 1 |
1068558 Starting Motor Gp-Electric*R
| 10***57 | Starting Motor Group-Electric; Electric Starting Motor Group (Robert Bosch) | 1 |
| 10***58 | Starting Motor Group-Electric | 1 |
| 10***59 | Starting Motor Group-Electric; Electric Starting Motor Group (Delco Remy) | 1 |
1068559 Starting Motor Gp-Electric
| 10***59 | Starting Motor Group-Electric; Electric Starting Motor Group (Delco Remy) | 1 |
1047040 Starting Motor Gp-Electric
| 10***40 | Starting Motor Group-Electric | 1 |
| 10***57 | Starting Motor Group-Electric; Electric Starting Motor Group (Robert Bosch) | 1 |
| 10***58 | Starting Motor Group-Electric | 1 |
6v5720 Starting Motor Gp-Electric
| 6V***20 | Starting Motor Group-Electric; (Electric) | 1 |
1068557 Starting Motor Gp-Electric
| 10***57 | Starting Motor Group-Electric; Electric Starting Motor Group (Robert Bosch) | 1 |
7n0718 Switch As-Disconnect
| 7N***18 | Switch As-Disconnect; -Battery-Ground Level | 1 |
1g9877 Warning Gp-Backup
| 1G***77 | Warning Group-Backup | 1 |
1052404 Wiring Gp-Vehicle
| 10***04 | Wiring Group | 1 |
1067174 Wiring Gp-Engine-Part 3 Of 3
| 10***74 | Wiring Group-Engine | 1 |
1067174 Wiring Gp-Engine-Part 2 Of 3
| 10***74 | Wiring Group-Engine | 1 |
1067174 Wiring Gp-Engine-Part 1 Of 3
| 10***74 | Wiring Group-Engine | 1 |
Engine Arrangement
1056144 Engine Ar-Part 1 Of 2
| 10***99 | Cover Group-Cylinder Block | 1 |
| 10***44 | Engine Ar | 1 |
| 10***08 | Gauge Group-Oil Level (Dipstick) | 1 |
1056144 Engine Ar-Part 2 Of 2
| 10***44 | Engine Ar | 1 |
| 10***71 | Pan Group-Oil | 1 |
| 10***32 | Pump Group-Fuel Injection | 6 |
Frame And Body
1052388 Bumper Gp-Drum
| 10***88 | Bumper Group-Drum | 1 |
1052251 Chassis Ar
| 10***51 | Chassis Ar | 1 |
| 10***87 | Frame Group-Compactor | 1 |
| 10***88 | Bumper Group-Drum | 1 |
1137365 Door Gp-Lh
| 11***65 | Door Group-Lh | 1 |
1060806 Door Gp-Lh
| 10***06 | Door Group-Lh | 1 |
1137368 Door Gp-Rh
| 11***68 | Door Group-Rh | 1 |
1219536 Door Gp-Rh
| 12***36 | Door Group-Rh | 1 |
1113764 Door Gp-Rh
| 11***64 | Door Group-Rh | 1 |
1219535 Enclosure Gp
| 12***35 | Enclosure Group | 1 |
1137364 Enclosure Gp
| 11***64 | Enclosure Group | 1 |
1113766 Enclosure Gp
| 11***66 | Enclosure Group | 1 |
1052387 Frame Gp-Compactor
| 10***87 | Frame Group-Compactor | 1 |
1117904 Hitch Gp-Oscillating
| 11***04 | Hitch Group-Oscillating | 1 |
1088617 Lines Gp-Drain
| 10***17 | Lines Group-Drain | 1 |
1232268 Lines Gp-Drain
| 12***68 | Lines Group-Drain | 1 |
1261334 Platform Gp-Operator
| 12***34 | Platform Group-Operator | 1 |
1052391 Scraper Gp-Drum
| 10***91 | Scraper Group-Drum | 1 |
Fuel System
7w6989 Control Gp-Fuel Injection
| 7W***89 | Control Group-Fuel Injection; Fuel Injection Control Group | 1 |
7e9429 Control Gp-Governor
| 7E***29 | Control Group-Governor | 1 |
1052395 Control Gp-Governor
| 10***95 | Control Group-Governor | 1 |
7e8794 Drive Gp-Governor & Transfer Pump
| 7E***94 | Drive Group-Gov & Transfer Pump | 1 |
7w4812 Fastener Gp-Governor
| 7W***12 | Fastener Group-Governor; Fastener Group(Governor) (~1c K5811) | 1 |
6i2693 Filter Gp-Fuel
| 6I***93 | Filter Group-Fuel; Fuel Filter Group (2z F3772-Up) | 1 |
1006179 Governor Gp-Unit Injector
| 10***79 | Governor Group-Unit Injector | 1 |
4p5512 Governor Gp-Unit Injector
| 4P***12 | Governor Group-Unit Injector | 1 |
7e7661 Governor Gp-Unit Injector
| 4P***12 | Governor Group-Unit Injector | 1 |
| 7E***61 | Governor Group-Unit Injector | 1 |
| 7W***12 | Fastener Group-Governor; Fastener Group(Governor) (~1c K5811) | 1 |
1314852 Governor Gp-Unit Injector
| 13***52 | Governor Group-Unit Injector | 1 |
1052384 Lines Gp-Fuel
| 10***84 | Lines Group-Fuel | 1 |
6i2420 Lines Gp-Fuel Filter
| 6I***20 | Lines Group-Fuel Filter; Fuel Filter Lines Group (1c K5248~) | 1 |
1136184 Lines Gp-Fuel Filter
| 11***84 | Lines Group-Fuel Filter | 1 |
7w8434 Lines Gp-Governor Oil
| 7W***34 | Lines Group-Governor Oil; Governor Oil Lines Group | 1 |
7e7607 Pump Gp-Fuel Injection
| 7E***07 | Pump Group-Fuel Injection; Fuel Injection Pump Group | 1 |
1077732 Pump Gp-Unit Injection
| 10***32 | Pump Group-Fuel Injection | 1 |
8n5251 Pump Gp-Fuel Prime & Priming Filter
| 8N***51 | Pump Group-Fuel Prime & Prim Filter | 1 |
8n3365 Pump Gp-Fuel Priming
| 8N***65 | Pump Group-Fuel Priming; Priming Pump-Fuel & Primary Filter | 1 |
Hydraulic System
871788 Cap Gp-Hydraulic Oil
| 08***88 | Cap Group-Hydraulic Oil Tank | 1 |
1209492 Control Gp-Hydraulic
| 12***92 | Control Group-Hydraulic | 1 |
1022012 Control Gp-Transmission
| 10***12 | Control Group-Transmission | 1 |
1g9894 Cylinder & Mounting Gp
| 1G***94 | Cylinder & Mtg Group-Steering | 1 |
1229784 Cylinder & Mounting Gp
| 12***84 | Cylinder & Mtg Group-Steering | 1 |
1g7089 Cylinder As-Hydraulic
| 1G***89 | Cylinder As-Hydraulic | 1 |
1126220 Cylinder Gp-Hydraulic
| 11***20 | Cylinder Group-Hydraulic | 1 |
9y0608 Drive Gp-Accessory
| 9Y***08 | Drive Group-Accessory | 1 |
1078334 Filter & Mounting Gp
| 10***34 | Filter & Mtg Group-Hydraulic | 1 |
1221786 Filter Gp-Oil
| 12***86 | Filter Group-Hydraulic; -Hydraulic | 1 |
1052255 Hydraulic Ar
| 10***55 | Hydraulic Ar | 1 |
| 10***99 | Lines Group-Hydraulic | 1 |
| 10***00 | Lines Group-Brake | 1 |
1171006 Hydraulic Ar
| 10***98 | Pump & Mounting Group | 1 |
| 11***97 | Valve Group-Brake | 1 |
| 11***01 | Lines Group-Brake | 1 |
1203984 Hydraulic Ar
| 10***98 | Pump & Mounting Group | 1 |
| 11***12 | Motor & Mounting Group | 1 |
| 11***88 | Motor & Mounting Group | 1 |
1052265 Hydraulic Ar-Auxiliary
| 10***65 | Hydraulic Ar-Auxiliary | 1 |
| 10***07 | Lines Group-Steering | 1 |
| 10***08 | Lines Group-Oil Cooler | 1 |
1052256 Hydraulic Ar-Vibrat0ry
| 10***56 | Hydraulic Ar-Vibratory | 1 |
| 10***02 | Lines Group-Vibratory | 1 |
| 10***99 | Valve & Mounting Group | 1 |
1052410 Lines Gp-Filter
| 10***10 | Lines Group-Filter | 1 |
1195992 Lines Gp-Hydraulic-Part 3 Of 3
| 11***92 | Lines Group-Hydraulic | 1 |
1141607 Lines Gp-Hydraulic-Part 3 Of 3
| 11***07 | Lines Group-Hydraulic | 1 |
1141607 Lines Gp-Hydraulic-Part 2 Of 3
| 11***07 | Lines Group-Hydraulic | 1 |
1141607 Lines Gp-Hydraulic-Part 1 Of 3
| 11***07 | Lines Group-Hydraulic | 1 |
1052399 Lines Gp-Hydraulic-Part 3 Of 3
| 10***99 | Lines Group-Hydraulic | 1 |
1052399 Lines Gp-Hydraulic-Part 1 Of 3
| 10***99 | Lines Group-Hydraulic | 1 |
1052399 Lines Gp-Hydraulic-Part 2 Of 3
| 10***99 | Lines Group-Hydraulic | 1 |
1195992 Lines Gp-Hydraulic-Part 2 Of 3
| 11***92 | Lines Group-Hydraulic | 1 |
1195992 Lines Gp-Hydraulic-Part 1 Of 3
| 11***92 | Lines Group-Hydraulic | 1 |
1235708 Lines Gp-Hydraulic Oil Cooler
| 12***08 | Lines Group-Hydraulic Oil Cooler | 1 |
1052408 Lines Gp-Oil Cooler
| 10***08 | Lines Group-Oil Cooler | 1 |
1090743 Lines Gp-Pilot
| 10***43 | Lines Group-Pilot | 1 |
1052402 Lines Gp-Vibratory-Part 2 Of 2
| 10***02 | Lines Group-Vibratory | 1 |
1052402 Lines Gp-Vibratory-Part 1 Of 2
| 10***02 | Lines Group-Vibratory | 1 |
1141612 Motor & Mounting Gp
| 11***12 | Motor & Mounting Group | 1 |
1164288 Motor & Mounting Gp
| 11***88 | Motor & Mounting Group | 1 |
1g9890 Motor & Mounting Gp
| 1G***90 | Motor & Mounting Group | 1 |
1g9890 Motor & Mounting Gp-Vibratory
| 1G***90 | Motor & Mounting Group | 1 |
1069466 Motor & Mounting Gp-Rear
| 10***66 | Motor & Mtg Group-Propel; -Rear | 1 |
1069466 Motor & Mounting Gp
| 10***66 | Motor & Mtg Group-Propel; -Rear | 1 |
1069467 Motor & Mounting Gp-Front
| 10***67 | Motor & Mtg Group-Propel; -Front | 1 |
1125733 Motor Gp-Piston-Vibratory
| 11***33 | Motor Group-Piston | 1 |
1203961 Motor Gp-Piston
| 12***61 | Motor Group-Piston | 1 |
1068924 Motor Gp-Piston-Front Propel
| 10***24 | Motor Group-Piston; -Front Propel | 1 |
1068925 Motor Gp-Piston-Rear Propel
| 10***25 | Motor Group-Piston; -Rear Propel | 1 |
1088398 Pump & Mounting Gp
| 10***98 | Pump & Mounting Group | 1 |
1091134 Pump & Mounting Gp-Power Steering
| 10***34 | Pump & Mounting Group | 1 |
1g9889 Pump & Mounting Gp
| 1G***89 | Pump & Mtg Group-Vibratory | 1 |
1091135 Pump Gp-Power Steering
| 10***35 | Pump Group | 1 |
1125730 Pump Gp-Piston-Part 2 Of 2
| 11***30 | Pump Group-Piston | 1 |
1221105 Pump Gp-Piston-Part 1 Of 2
| 12***05 | Pump Group-Piston | 1 |
1221105 Pump Gp-Piston-Part 2 Of 2
| 12***05 | Pump Group-Piston | 1 |
1125730 Pump Gp-Piston-Part 1 Of 2
| 11***30 | Pump Group-Piston | 1 |
1125732 Pump Gp-Piston
| 11***32 | Pump Group-Piston | 1 |
1193135 Pump Gp-Piston
| 11***35 | Pump Group-Vibratory; (Vibratory) | 1 |
1g9842 Tank & Mounting Gp-Hydraulic
| 1G***42 | Tank & Mtg Group-Hydraulic & Fuel | 1 |
1088399 Valve & Mounting Gp
| 10***99 | Valve & Mounting Group | 1 |
1039610 Valve Gp
| 10***10 | Valve Group | 1 |
1020257 Valve Gp-Control
| 10***57 | Valve Group-Control | 1 |
1192066 Valve Gp-Flushing
| 11***66 | Valve Group-Flushing | 1 |
1137137 Valve Gp-Pressure Control
| 11***37 | Valve Group-Pressure Control | 1 |
1214371 Valve Gp-Vibratory
| 12***71 | Valve Group-Vibratory | 1 |
1279815 Valve Gp-Solenoid & Relief
| 12***15 | Valve Group-Vibratory; (Cooling/Control) | 1 |
1173641 Valve Gp-Vibratory
| 11***41 | Valve Group-Vibratory | 1 |
Lubrication System
1n3477 Breather Gp
| 1N***77 | Breather Group; Breather Group | 1 |
1088527 Filler Gp-Oil
| 10***27 | Filler Group-Oil | 1 |
7c0271 Filter Gp-Engine Oil
| 7C***71 | Filter Group-Engine Oil | 1 |
7w8420 Fumes Disposal Gp
| 7W***20 | Fumes Disposal Group; Fumes Disposal Group | 1 |
1071308 Gauge Gp-Oil Level(Dipstick)
| 10***08 | Gauge Group-Oil Level (Dipstick) | 1 |
4w2914 Lines Gp-Engine Oil
| 4W***14 | Lines Group-Engine Oil | 1 |
1w6030 Lines Gp-Turbocharger Oil
| 1W***30 | Lines Group-Turbocharger Oil | 1 |
4w2195 Pump Gp-Engine Oil-One Section Gear
| 4W***95 | Pump Group-Engine Oil; Engine Oil Pump Group | 1 |
2w8625 Pump Gp-Engine Oilone Section Gear*R
| 2W***25 | Pump Group-Engine Oil | 1 |
1192924 Pump Gp-Engine Oil
| 11***24 | Pump Group-Engine Oil | 1 |
Operator Station
1054029 Warning Gp-Operator
| 10***29 | Alarm Group | 1 |
1020253 Console Gp-Instrument
| 10***53 | Console Group-Instrument | 1 |
1090404 Console Gp-Instrument
| 10***53 | Console Group-Instrument | 1 |
| 10***04 | Console Group-Instrument | 1 |
1020265 Console Gp-Operator
| 10***65 | . Sprocket (Mitsubishi Eng.) (Cummins Eng.), Console Group-Operator, . Sprocket | 1 |
1112294 Guard Gp-Platform
| 11***94 | Guard Group-Platform | 1 |
1166679 Guard Gp-Platform
| 11***79 | Guard Group-Platform | 1 |
1087735 Guard Gp-Vandalism
| 10***35 | Guard Group-Vandalism | 1 |
1019559 Lock Gp-Rotate
| 10***59 | Lock Group-Rotate | 1 |
1060341 Mat Gp-Cocoa
| 10***41 | Mat Group-Cocoa | 1 |
1228681 Meter Gp-Vibratory
| 12***81 | Meter Group-Vibratory | 1 |
1061238 Mounting Gp-Wheel
| 10***38 | Mounting Group-Wheel | 1 |
1052252 Operator Ar
| 10***59 | Lock Group-Rotate | 1 |
| 10***54 | Seat Group-Suspension | 1 |
| 10***55 | Platform Group-Operator | 1 |
1020255 Platform Gp-Operator
| 10***55 | Platform Group-Operator | 1 |
1166677 Platform Gp-Tilt
| 11***77 | Platform Group-Tilt | 1 |
1115161 Platform Gp-Tilt
| 11***61 | Platform Group-Tilt | 1 |
1073171 Rops Gp
| 10***71 | Rops Group | 1 |
1171350 Rops Gp
| 11***50 | Rops Group | 1 |
1022423 Seat Gp-Suspension
| 10***23 | Seat Group-Suspension | 1 |
1020254 Seat Gp-Suspension
| 10***54 | Seat Group-Suspension | 1 |
1071229 Speedometer Gp
| 10***29 | Speedometer Group | 1 |
1159962 Suspension Gp-Seat
| 11***62 | Suspension Group-Seat | 1 |
1041978 Switch Gp
| 10***78 | Switch Group-Speed | 1 |
9g7641 Switch Gp-Start
| 9G***41 | Switch Group-Start; -Engine, Key-Vims Service | 1 |
Power Train
1142265 Drive Gp-Drum-Front
| 11***65 | Drive Group-Drum | 1 |
1092731 Drive Gp-Drum-Rear
| 10***31 | Drive Group-Drum; Drive Gp-Drum-Rear | 1 |
1068922 Drive Gp-Drum-Front
| 10***22 | Drive Group-Drum | 1 |
1064856 Drive Gp-Pump
| 10***56 | Drive Group-Pump | 1 |
1052403 Drum Gp
| 10***03 | Drum Group | 1 |
1068927 Gear Gp
| 10***27 | Gearbox Group-Drum Drive | 1 |
1068929 Gear Gp
| 10***29 | Gearbox Group-Drum Drive; -Rear | 1 |
1131531 Installation Gp
| 11***31 | Installation Group-Drum | 1 |
1052259 Power Train Ar
| 10***59 | Power Train Ar | 1 |
| 10***03 | Drum Group | 2 |
| 10***22 | Drive Group-Drum | 1 |
1086567 Drive Shaft Gp
| 10***67 | Shaft Group-Drive | 1 |
1465794 Weight Gp-Eccentric
| 14***94 | Weight Group-Eccentric | 1 |
1059054 Eccentric Gp
| 10***54 | Weight Group-Eccentric | 1 |
Service Equipment And Supplies
1100090 Film Gp-English
| 11***90 | Film Group-English | 1 |
Nameplate & Films
| 10***64 | Film; (Identification) (Engine Oil Filter) | 0 |
| 3N***69 | Tag-Instruction; (Engine Prestart)(English And Spanish) | 0 |
| 4P***81 | Film Identification; (Oil Filter) (On Oil Filter) | 0 |
1052390 Paint & Transfer Gp
| 10***90 | Paint & Film Group | 1 |
Steering System
1020258 Control Gp-Steering
| 10***58 | Control Group-Steering | 1 |
1052394 Lines Gp-Steering
| 10***94 | Lines Group-Steering | 1 |
1052407 Lines Gp-Steering Oil
| 10***07 | Lines Group-Steering | 1 |
1g9217 Pump Gp-Hand
| 1G***17 | Pump Group-Metering | 1 |
Water System
1079179 Mat Gp-Water Distribution
| 10***79 | Mat Group-Water Distribution | 1 |
1080326 Pump Gp-Water
| 10***26 | Pump Group-Water | 1 |
6r2383 Pump Gp-Water
| 6R***83 | Pump Group-Water Spray | 1 |
1075882 Pump Gp-Water
| 10***82 | Pump Group-Water Spray | 1 |
1052253 Spray Ar
| 10***53 | Spray Ar | 1 |
| 10***98 | Spray Group-Water | 1 |
| 11***93 | Spray Group-Water | 1 |
1060336 Pipe Gp-Sprayer
| 10***36 | Spray Bar As | 1 |
1233189 Spray Gp-Water
| 12***89 | Spray Group-Water | 1 |
1052398 Spray Gp-Water
| 10***98 | Spray Group-Water | 1 |
1141593 Spray Gp-Water
| 11***93 | Spray Group-Water | 1 |
1102101 Tank Gp-Water
| 11***01 | Tank Group-Water, . Pipe | 1 |
CB-634 serial number reference
The PIN plate on the CB-634 is a metal tag riveted to the machine frame; exact mounting position (frame rail vs. articulation joint) is not documented consistently for this range, so check the frame visually or consult the operation and maintenance manual for the exact spot on your unit. The PIN reads as a 3-character alphanumeric prefix followed by a sequential serial number (example: 3BR00512); the prefix identifies the specific model/generation build (base, C-series, D-series) and the trailing digits identify that individual unit's build sequence.
| Prefix | Identifies | Notes |
|---|---|---|
| 5CL | CB-634 (base/first-generation double-drum vibratory asphalt compactor) | Serial range 5CL1-Up (5CL00001-Up). Fitted with the Cat 3116 diesel engine. Earliest CB-634 generation, production traced to the mid-1990s from parts-catalog and market listings; treat exact start/end years as approximate and confirm with a dealer for edge-of-range units. |
| 3BR | CB-634C (double-drum vibratory asphalt compactor, C-series update) | Serial range 3BR1-Up (3BR00001-Up). Fitted with the Cat 3116 diesel engine. C-series introduced in the 1990s as the successor to the base CB-634; shares driveline architecture with the CB-534C. |
| CDF | CB-634D (double-drum vibratory asphalt compactor, D-series update) | Serial range CDF1-Up (CDF00001-Up). Fitted with the Cat 3116T turbocharged diesel engine, gross power 108 kW (145 hp). D-series introduced in the early 2000s as the successor to the CB-634C; later succeeded by the CB64 line. |
Frequently asked questions
What engine does the Caterpillar CB-634 use?
The CB-634 runs Caterpillar's 3116T turbocharged diesel inline-six, rated at roughly 108 kW (145 hp) gross and 103 kW (138 hp) net on the documented C and D series. Records for the earliest base CB-634 and CB-634B are limited, so confirm the engine and rating on early-serial units against the machine's build plate or a dealer parts lookup.
What is the CB-634's operating weight?
Operating weight runs roughly 12.2-12.8 tonnes (26,900-28,200 lb) depending on configuration and series — cab versus ROPS canopy, water tank fill level, and series updates all shift the number. Treat any single published figure as a configuration-specific example rather than a fixed spec.
What replaced the Caterpillar CB-634?
Caterpillar retired the CB-634 designation without naming a direct one-for-one successor. The 12-13 tonne tandem vibratory roller class it occupied is now served by Cat's newer CB13 and CB15 tandem vibratory rollers, though those are different-generation machines rather than a badge-engineered replacement.
What CB-634 owners discuss
What engine does the CB-634 use, and what do owners say about its long-term reliability?
The CB-634D factory spec sheet lists a Cat 3116T turbocharged inline-six diesel rated about 108 kW (145 hp) gross / 103 kW (138 hp) net. Earlier B and C configurations are commonly assumed to share this engine family, but that isn't separately confirmed on available spec sheets, so verify the engine plate on any B or C unit before assuming parts commonality. Field reports on the 3116T are mixed: the block and injection system are considered durable once broken in, but injector cup O-rings are a well-known wear point on this engine family - a failed cup lets coolant or combustion gas cross into the cylinder and gets misread as a head gasket or ring problem. HEUI-pump hard starting is another recurring complaint, and it usually traces back to a clogged fuel tank vent starving the pump rather than pump failure itself. Keep the tank breather clear and rule out injector cups before chasing a bottom-end diagnosis.
What hydraulic propel and drive behavior shows up as the machine ages?
Owners of this class of double-drum roller flag softening propel speed, hesitation on forward/reverse reversal, and weeping hose fittings as the hydraulic pump and drive motors rack up hours. None of this is unique to the CB-634 - it's the standard wear curve for a hydrostatic propel system this size - but a machine that lurches or delays on direction change, or needs the throttle held up just to move, is telling you the pump or motor is losing volumetric efficiency. Check hydraulic tank fluid condition and filter change history alongside a road test in both directions before assuming it's just a linkage adjustment.
What wear pattern do the drums and vibratory (exciter) system show over time?
This is a 2.13 m (84 in) wide double-drum vibratory machine running an exciter shaft at roughly 44 Hz, with amplitude-dependent centrifugal force in the 58-159 kN (13,000-35,700 lbf) range per the factory spec sheet. Exciter bearings and eccentric-housing seals are the wear items to watch: a drop in compaction force, a knock from inside the drum at speed, or an oil weep at the housing all point to bearing wear rather than a hydraulic fault. Weekly checks of the vibration bearings and water spray nozzles are the standard maintenance rhythm for this machine type. Because a failing exciter bearing can let the shaft shift under load, have your dealer verify exciter shaft and bearing condition before putting a drum showing these symptoms back into vibratory service.
Why does the water spray system clog, and how do owners deal with it?
Asphalt sticking to the drum instead of transferring to the mat is almost always a water delivery problem, not a drum problem. The system relies on a strainer at the fill port plus screens at the pump and each nozzle; once scraper bars wear or go out of adjustment, water stops reaching the drum edges evenly and asphalt starts picking up and marring the finish. The routine fix owners use is flushing the tank and cleaning strainers on a set interval rather than waiting for a nozzle to fully plug, and replacing scraper bars once they lose their edge or adjustment range.
What electrical or sensor faults come up most often?
The platform runs a 12V system with a 105-amp alternator. The most repeated complaint tied to 3116T-powered Cat equipment generally is starter solenoid failure - a slow or no-crank condition that isn't actually a battery problem. On articulated machines like this one, the wiring harness that crosses the center pivot is also a known chafe point; intermittent vibration on/off faults or steering-related sensor codes often trace back to worn harness insulation at the articulation joint rather than a bad switch or sensor. Inspect harness routing at the pivot early in any intermittent-electrical diagnosis.
What should I know about the articulation (steering) joint wear on this roller?
Like other articulated compactors, the CB-634 steers by pivoting at a center joint rather than through steered wheels. The pin and bushings at that joint wear with hours and with missed grease intervals, showing up as steering play, a wander at speed, or a clunk on direction change. Because the articulation joint is part of the steering system, looseness here is a control issue, not just a comfort one. Have your dealer verify articulation pin and bushing wear, along with steering cylinder condition, on any machine that shows steering play before it goes back to work.
What should I check when buying a used CB-634?
Confirm which series you're looking at (B, C, or D) since engine and control details can differ by build, and match the engine plate rather than assuming. On the engine, check for coolant in the oil or oil in the coolant (the classic injector-cup symptom) and note any hard or slow starting that might point to a fuel tank vent issue rather than pump wear. On the drums, look for surface pitting or gouging, listen for knock from the exciter at idle vibration, and check for oil weep at the eccentric housing seals. Run the water spray system through a full cycle and confirm even flow at all nozzles. Road test propel in both directions for hesitation or drift, and check hydraulic hoses for weeping. Work the articulation joint lock-to-lock and feel for play at the center pin. Confirm all switches, gauges, and the vibration on/off control function correctly. Ask for service records matched to the hour meter rather than relying on the meter alone. Because several of these checks touch steering and vibratory-system safety, have your dealer verify articulation joint, exciter bearing, and hydraulic brake condition before you put the machine to work.
Compiled from owner and technician discussions across the industry — experiences vary by serial range and machine history.
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