Caterpillar S40
Maintenance schedule, common problems & OEM parts breakdown
The Cat S40 is a pin-grabber quick coupler in Caterpillar's S-Type coupler line, sized for 3-4 ton and 5-6 ton mini excavators; overall width, length, and pin diameter scale up between the two tonnage classes even though both carry the S40 name. It mounts between the excavator's stick and its buckets or work tools, using a wedge-type locking mechanism driven by a single hydraulic cylinder tied into the host machine's dedicated coupler circuit. It ships in a standard version with a visual lock-verification rod, and an LCS version that adds an electronic position sensor and digital lock-confirm signal to the excavator's ECM on Next Generation mini excavators. Rated lifting hook capacity is 2000 kg (4409 lb) across variants, weight runs roughly 43-48 kg (95-106 lb) depending on tonnage class and configuration, and maximum operating pressure is about 300 bar (4351 psi). The same S40 coupler also serves as the pin-grabber head on Cat's TRS4 and TRS6 tiltrotator systems.
There's no generational succession for the S40 the way a powered machine has one model replace another; it sits in a size ladder alongside the S30, S45, S50, S60, S70, and S80 couplers, each scoped to a carrier weight class rather than a production era. The real change across S40 configurations is standard-versus-LCS: the LCS variant swaps the plain visual verification rod for an electronic sensor that reports lock state straight to the excavator's cab display, cutting reliance on the operator eyeballing the rod from the seat. In the used and parts market, couplers like the S40 matter because they outlive the buckets and tools cycled through them and often outlast the excavator they were bought with; fast tool-change capability drives resale value on the carrier, while wedge, bushing, pin, and lock-cylinder wear parts see steady replacement demand across a fleet's working life.
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 S40 specifications
Engine
| Power source | Passive hydraulic work tool — no engine, ECM, or onboard power source. Runs off the host mini excavator's dedicated, factory-installed coupler hydraulic circuit. |
| Emissions tier | Not applicable — no engine fitted. |
Weights
| Coupler weight, S40 Pin Grabber (5-6 ton class, standard lock) | 48 kg (105.8 lb) |
| Coupler weight, S40 Pin Grabber LCS (5-6 ton class, electronic lock confirmation) | 49 kg (108 lb) |
| Coupler weight, S40 Pin Grabber LCS (3-4 ton class, electronic lock confirmation) | 43 kg (94.8 lb) |
Dimensions
| Overall length (5-6 ton class, standard and LCS) | 495 mm (19.5 in) |
| Overall width (5-6 ton class, standard and LCS) | 282 mm (11.1 in) |
| Overall height (5-6 ton class, standard and LCS) | 272 mm (10.7 in) |
| Pin diameter (5-6 ton class) | 46 mm (1.8 in) |
| Overall length (3-4 ton class, LCS) | 470 mm (18.5 in) |
| Overall width (3-4 ton class, LCS) | 254 mm (10 in) |
| Overall height (3-4 ton class, LCS) | 262 mm (10.3 in) |
| Pin diameter (3-4 ton class, LCS) | 40 mm (1.6 in) |
Performance
| Lifting hook capacity (all configurations) | 2000 kg (4409 lb) |
| Maximum hydraulic operating pressure (all configurations) | 300 bar (4351 psi) |
| Locking system, standard | Wedge-type pin-grabber lock with low offset for a tight, play-free fit to the attachment. |
| Locking system, LCS variants | Adds an electronic position sensor in the coupler cylinder feeding a processor, plus a visual verification rod so the operator can confirm from the cab that the lock has engaged. |
Service capacities (summary)
| Fuel, hydraulic reservoir, engine oil, coolant | Not applicable. No engine and no independent hydraulic reservoir — the tool runs on the host carrier's dedicated hydraulic circuit, which must be factory installed. |
Values vary by configuration, region, and serial range — confirm against your machine before planning transport or lifts.
S40 fluids & capacities
| System | Capacity | Recommended fluid |
|---|---|---|
| Engine crankcase, cooling system, fuel tank, transmission/powertrain, final drives, axles/differentials | Not applicable | The S40 is a passive pin-grabber quick coupler with no engine, no coolant circuit, no fuel tank, and no powertrain or axle components, so the OMM lists no lubricant/fluid rows for these systems. |
| Hydraulic lock circuit | No dedicated tank or reservoir on the coupler itself | The coupler's lock cylinder draws hydraulic power from the host mini excavator's own dedicated coupler circuit through the stick-mounted hose and fitting connections. Fluid type and capacity follow the host machine's OMM, not a separate S40 chart. |
| Grease - pin bore, wedge lock mechanism, and pivot points | No published refill-capacity chart specific to the S40; grease before each shift or per the coupler's lubrication chart | Standard NLGI grade 2 multipurpose EP grease at the pin contact points and lock mechanism. No climate-specific viscosity split or exact interval hours are published for this coupler; follow general Cat quick-coupler lubrication practice and wipe nipples clean before greasing. |
Capacities are refill values from factory literature — always fill to the dipstick/sight gauge, not the number.
Caterpillar S40 maintenance schedule
| Service interval | Tasks |
|---|---|
| Every 50 h |
|
| Every 250 h |
|
| Every 500 h |
|
| Every 1,000 h |
|
| Every 2,000 h |
|
| Every 4,000 h |
|
Servicing the S40 beyond the schedule
Predictive Maintenance & Fluid Analysis
The S40 has no reservoir or pump of its own; its lock cylinder runs entirely off the host excavator's hydraulic circuit. Predictive care means watching that host circuit's fluid cleanliness and pressure, since contaminated oil is the leading cause of a sluggish or sticking wedge. On LCS units, log the lock-confirm sensor's response time at each hitch cycle; a lengthening delay before confirm flags cylinder wear or seal leak before it becomes a no-lock fault.
Corrective & Common Repairs
Common S40 complaints are wedge play (rattle in the pin bore), a lock cylinder that hangs up mid-stroke from packed debris or worn seals, and a verification rod that won't sit flush even though the wedge is fully seated. On LCS couplers, a false not-locked indication on the excavator display is usually a corroded or loose harness connector at the coupler body, not a sensor failure. Clean, dry, and reseat connectors before condemning the sensor or processor.
Overhaul & Rebuild Points
Rebuild work centers on the pin bores, wedge, and lock-body wear faces. Once bore clearance exceeds the wear limit, bores get bushed or re-machined oversize and the wedge resurfaced or replaced to restore a tight, play-free lock. Lock cylinder overhaul means new seals and rod inspection for scoring; a scored rod should be replaced, not reused. Check the lifting hook and mounting ears for crack initiation at weld toes, since these carry the full rated 2000 kg (4409 lb) load.
Seasonal & Environmental Servicing
Cold weather thickens pivot grease and slows lock cylinder response, so switch to a low-temperature grease and expect a longer lock-confirm delay on LCS units until the host machine's hydraulic oil warms. Demolition, utility, and trenching work packs mud and spoil into the wedge pocket and pin bore; clear it before every attachment change so the wedge seats fully. Wash the coupler body down regularly since a housing full of grit accelerates pin bore and wedge wear even though the internals are shielded.
S40 fault codes & troubleshooting
| Code | Meaning | Likely cause | What to do |
|---|---|---|---|
| Lock-status indicator: locked (visual verification rod extended / green display icon) | Locking wedge is fully engaged and the pin is captured | Normal locked state, not a fault | No action required; confirm rod position visually before operating |
| Lock-status indicator: not locked (visual verification rod retracted / red or amber display icon) | Locking wedge has not reached the confirmed-locked position | Incomplete lock cycle, attachment pin not fully seated, low hydraulic pressure to the lock circuit, or on LCS units a position-sensor/harness fault preventing confirmation | Cycle the lock function again with the attachment pins fully seated; if it still will not confirm locked, inspect the lock cylinder, wedge, and (on LCS units) the sensor connector and harness before returning to service |
Codes and remedies are general guidance for this model family — always confirm with diagnostic tooling and your dealer before major repairs.
S40 attachments & work tools
S-Type Coupler (S40 Pin Grabber)
S40 is a pin-grabber style dedicated quick coupler for Cat mini excavators from roughly 3 to 6 tonnes. It uses a wedge-type hydraulic lock to minimize impact loading and hold the attachment pin under positive pressure, with a visual verification rod so the operator can confirm lock-up from the cab. Weight is about 48 kg (105.8 lb), width about 281 mm (11.1 in), rated lifting-hook capacity about 2000 kg (4409 lb), and max operating pressure about 300 bar (4351 psi).
Coupler control/lock variants
The S40 line is offered as a standard hydraulic pin-grabber, an LCS (Locking Control System) version with an electronic position sensor in the lock cylinder feeding the machine's ECM over a wiring harness for cab-level lock confirmation, and a Secure Lock variant. All share the same wedge-lock, pin-on interface across the 3-6 ton class; exact variant availability varies by machine serial prefix and market.
Digging and general-purpose buckets
Digging and GP buckets for this size class typically run in the roughly 300-900 mm (12-36 in) width range with capacities in the tenths of a cubic meter, pin-on through the S40 interface with bolt-on or heavy-duty tooth options. Exact width/capacity offering varies by configuration and dealer catalog.
Grading and ditching buckets
Wide grading/ditching buckets up to roughly 1500 mm (60 in) are offered for 5-6 ton carriers for slope finishing and ditch work, mounted through the same S40 pin-on interface as digging buckets.
Hydraulic hammers/breakers
Cat B-series and H-series hydraulic hammers sized for the 3.5-6 tonne carrier range (for example the H35E/H45E family) mount via the S40 pin-on interface and run off the excavator's auxiliary hydraulic circuit. These require a factory or field-installed auxiliary hydraulic kit matched to the machine's serial-number prefix; base bucket work does not.
Grapples
The Cat G306 rotating grapple is built for 5-6 ton mini excavators, with a material capacity of about 160 L (0.21 yd3). Open/close is run off the machine's first auxiliary hydraulic function and 360-degree bidirectional rotation off the second, mounted through the S40 coupler.
Hydraulic thumbs
Pro Series (Pro and Pro Plus) hydraulic thumbs and Stiff Link (rigid, non-hydraulic) thumbs are offered for this carrier class. Hydraulic thumb versions need the excavator's auxiliary circuit; the stiff-link mechanical thumb needs none.
Tiltrotator (TRS4 on S40)
The TRS4 tiltrotator pairs with the S40 pin-grabber coupler for 3-4 ton mini excavators, weighing about 120 kg (264.6 lb), giving 360-degree continuous rotation and about 40 degrees of side-to-side tilt via a worm-gear drivetrain with a single-point grease fitting. Compatibility is restricted to specific machine serial-number prefixes (e.g. 303, 303.5, 304 ranges) rather than the whole size class, so confirm fit by serial prefix before ordering.
Augers
Auger drives sized for this weight class mount via the S40 pin-on interface and require dedicated auxiliary hydraulic flow, supplied through the same field-installed or factory auxiliary hydraulic kit used for hammers and grapples.
Auxiliary hydraulic kit requirement
Hammers, grapples, hydraulic thumbs, and augers all require the excavator's auxiliary hydraulic circuit; Cat's field-installed hydraulic kits are matched to the specific machine serial-number prefix and configuration. Basic buckets need only the coupler's own hydraulic lock circuit, no separate auxiliary kit.
Coupler size family / factory configuration
S40 denotes the coupler size code for the 3-6 ton mini excavator range; larger Cat mini/compact excavator classes step up to S50 (about 8-10 ton) and S60 couplers. Coupler size is tied to carrier weight class and is not interchangeable across classes.
All S40 assemblies by section
Every catalogued assembly group for the Caterpillar S40. Open an assembly to preview the parts inside — full OEM part numbers are available in Heavy Parts AI.
Frame And Body
144-0965 Housing Gp-Shear
| 09***05 | Bolt-Socket Head; (M16x2x100-mm) | 3 |
| 10***55 | Plate-Warning | 1 |
| 13***24 | Screw-Flat Head | 26 |
144-0988 Housing Gp-Shear
| 09***05 | Bolt-Socket Head; (M16x2x100-mm) | 3 |
| 10***55 | Plate-Warning | 1 |
| 12***54 | Screw-Flat Head; (M12x1.75x35-mm) | 16 |
144-0973 Housing Gp-Shear
| 09***05 | Bolt-Socket Head; (M16x2x100-mm) | 3 |
| 14***73 | Housing Group-Shear | 1 |
| 14***59 | Retainer | 2 |
144-3082 Housing Gp-Shear
| 14***67 | Swivel As | 1 |
| 14***03 | Housing As | 1 |
| 14***14 | Lockwasher | 4 |
144-3072 Housing Gp-Shear
| 09***05 | Bolt-Socket Head; (M16x2x100-mm) | 3 |
| 12***54 | Screw-Flat Head; (M12x1.75x35-mm) | 16 |
| 14***63 | Lockwasher | 16 |
144-0998 Housing Gp-Shear
| 14***98 | Housing Group-Shear | 1 |
| 14***67 | Swivel As | 1 |
| 14***03 | Housing As | 1 |
144-3066 Housing Gp-Shear
| 09***05 | Bolt-Socket Head; (M16x2x100-mm) | 3 |
| 12***54 | Screw-Flat Head; (M12x1.75x35-mm) | 16 |
| 14***73 | Lockwasher | 16 |
144-0978 Housing Gp-Shear
| 09***05 | Bolt-Socket Head; (M16x2x100-mm) | 3 |
| 10***55 | Plate-Warning | 1 |
| 12***54 | Screw-Flat Head; (M12x1.75x35-mm) | 16 |
144-0959 Housing Gp-Shear
| 14***59 | Housing Group-Shear | 1 |
| 14***48 | Pin | 1 |
| 14***52 | Bushing | 2 |
160-7473 Housing Gp-Shear
| 09***05 | Bolt-Socket Head; (M16x2x100-mm) | 3 |
| 12***54 | Screw-Flat Head; (M12x1.75x35-mm) | 16 |
| 14***63 | Lockwasher | 16 |
152-3850 Housing Gp-Shear
| 09***05 | Bolt-Socket Head; (M16x2x100-mm) | 3 |
| 14***59 | Retainer | 2 |
| 14***63 | Lockwasher | 22 |
144-3063 Housing Gp-Shear
| 09***05 | Bolt-Socket Head; (M16x2x100-mm) | 3 |
| 14***59 | Retainer | 2 |
| 14***63 | Lockwasher | 26 |
156-4984 Housing Gp-Shear
| 09***05 | Bolt-Socket Head; (M16x2x100-mm) | 3 |
| 12***54 | Screw-Flat Head; (M12x1.75x35-mm) | 16 |
| 14***59 | Retainer | 2 |
178-6221 Housing Gp-Shear
| 14***67 | Swivel As | 1 |
| 14***93 | Bumper | 8 |
| 14***06 | Bolt-Socket Head; (M20x2.5x140-mm) | 4 |
144-3146 Mounting Gp-Rotator Cylinder
| 14***88 | Bolt-Socket Head | 8 |
| 14***89 | Bolt-Socket Head | 8 |
| 14***46 | Mounting Group-Rotator Cylinder | 1 |
144-6042 Mounting Gp-Rotator Cylinder
| 14***42 | Mounting Group-Rotator Cylinder | 1 |
| 14***43 | Coupling | 2 |
| 14***44 | Pin | 2 |
144-3765 Mounting Gp-Rotator Cylinder
| 14***97 | Bolt-Socket Head; (M20x2.5x120-mm) | 8 |
| 14***65 | Mounting Group-Rotator Cylinder | 1 |
| 14***66 | Coupling | 1 |
144-6146 Mounting Gp-Rotator Cylinder
| 14***97 | Bolt-Socket Head; (M20x2.5x120-mm) | 12 |
| 14***07 | Bolt-Socket Head | 12 |
| 14***46 | Mounting Group-Rotator Cylinder | 1 |
144-4214 Mounting Gp-Rotator Cylinder
| 14***84 | Bolt-Socket Head; (M20x2.5x110-mm) | 14 |
| 14***14 | Mounting Group-Rotator Cylinder | 1 |
| 14***15 | Coupling | 1 |
144-2762 Mounting Gp-Rotator Cylinder
| 09***06 | Bolt-Socket Head; (M16x2x80-mm) | 8 |
| 14***91 | Coupling | 1 |
| 14***92 | Pin | 1 |
Hydraulic System
144-0975 Cylinder & Lines Gp-Rotator
| 14***75 | Cylinder & Lines Group-Rotator | 1 |
| 14***63 | Cylinder Group-Rotator | 1 |
| 14***65 | Mounting Group-Rotator Cylinder | 1 |
144-0968 Cylinder & Lines Gp-Rotator
| 14***68 | Cylinder & Lines Group-Rotator | 1 |
| 14***44 | Cylinder Group-Rotator | 1 |
| 14***46 | Mounting Group-Rotator Cylinder | 1 |
144-0980 Cylinder & Lines Gp-Rotator
| 14***80 | Cylinder & Lines Group-Rotator | 1 |
| 14***12 | Cylinder Group-Rotator | 1 |
| 14***14 | Mounting Group-Rotator Cylinder | 1 |
144-0961 Cylinder & Lines Gp-Rotator
| 14***61 | Cylinder & Lines Group-Rotator | 1 |
| 14***34 | Lines Group-Rotator Cylinder | 1 |
| 14***88 | Cylinder Group-Rotator | 1 |
144-1000 Cylinder & Lines Gp-Rotator
| 14***00 | Cylinder & Lines Group-Rotator | 1 |
| 14***12 | Cylinder Group-Rotator | 2 |
| 14***42 | Mounting Group-Rotator Cylinder | 1 |
145-6218 Cylinder & Lines Gp-Rotator
| 14***65 | Mounting Group-Rotator Cylinder | 1 |
| 14***00 | Cylinder Group-Rotator | 1 |
| 14***17 | Lines Group-Rotator Cylinder | 1 |
144-0990 Cylinder & Lines Gp-Rotator
| 14***90 | Cylinder & Lines Group-Rotator | 1 |
| 14***44 | Cylinder Group-Rotator | 1 |
| 14***46 | Mounting Group-Rotator Cylinder | 1 |
144-0979 Cylinder & Lines Gp-Shear
| 14***79 | Cylinder & Lines Group-Shear | 1 |
| 14***94 | Cylinder Group-Hydraulic | 1 |
| 14***99 | Mounting Group-Cylinder | 1 |
144-0989 Cylinder & Lines Gp-Shear
| 14***89 | Cylinder & Lines Group-Shear | 1 |
| 14***26 | Cylinder Group-Hydraulic | 1 |
| 14***31 | Fuel Filter; Sieve, Fuel Filter, Mounting Group-Cylinder | 1 |
144-0966 Cylinder & Lines Gp-Shear
| 14***66 | Cylinder & Lines Group-Shear | 1 |
| 14***27 | Cylinder Group-Shear | 1 |
| 14***32 | Mounting Group-Cylinder | 1 |
152-3849 Cylinder & Lines Gp-Shear
| 15***84 | Cylinder Group-Hydraulic | 1 |
| 15***99 | Lines Group-Cylinder | 1 |
| 15***01 | Mounting Group-Cylinder | 1 |
144-0999 Cylinder & Lines Gp-Shear
| 14***99 | Cylinder & Lines Group-Shear | 1 |
| 14***20 | Cylinder Group-Hydraulic | 1 |
| 14***25 | Mounting Group-Cylinder | 1 |
144-0960 Cylinder & Lines Gp-Shear
| 14***60 | Cylinder & Lines Group-Shear | 1 |
| 14***44 | Cylinder Group-Hydraulic | 1 |
| 14***48 | Mounting Group-Cylinder | 1 |
144-0974 Cylinder & Lines Gp-Shear
| 14***74 | Cylinder & Lines Group-Shear | 1 |
| 14***42 | Cylinder Group-Hydraulic | 1 |
| 14***47 | Mounting Group-Cylinder | 1 |
144-3742 Cylinder Gp-Hydraulic
| 09***77 | Setscrew-Socket | 1 |
| 14***31 | Ring-Retaining | 4 |
| 14***42 | Cylinder Group-Hydraulic | 1 |
144-4194 Cylinder Gp-Hydraulic
| 09***13 | Ring | 4 |
| 09***77 | Setscrew-Socket | 1 |
| 14***94 | Cylinder Group-Hydraulic | 1 |
158-3051 Cylinder Gp-Hydraulic
| 03***25 | Ring-Backup | 2 |
| 08***91 | Ring-Backup | 1 |
| 08***93 | Ring-Retaining | 1 |
160-8244 Cylinder Gp-Hydraulic -Y
| 00***50 | Seal-O-Ring | 1 |
| 10***96 | Ring-Retaining | 4 |
| 10***25 | Seal As | 1 |
144-6126 Cylinder Gp-Hydraulic
| 09***77 | Setscrew-Socket | 1 |
| 10***60 | Ring-Retaining | 4 |
| 14***06 | Bolt-Socket Head; (M20x2.5x140-mm) | 18 |
144-2744 Cylinder Gp-Hydraulic
| 14***44 | Cylinder Group-Hydraulic | 1 |
| 14***45 | Seal Set | 1 |
| 14***31 | Ring-Retaining | 4 |
145-3750 Cylinder Gp-Hydraulic
| 03***25 | Ring-Backup | 1 |
| 09***33 | Seal-O-Ring; (Id=209.30mm) | 1 |
| 10***86 | Ring-Retaining | 1 |
144-6020 Cylinder Gp-Hydraulic
| 10***96 | Ring-Retaining | 4 |
| 14***20 | Cylinder Group-Hydraulic | 1 |
| 14***22 | Seal Set | 1 |
152-3684 Cylinder Gp-Hydraulic
| 03***25 | Ring-Backup | 2 |
| 09***33 | Seal-O-Ring; (Id=209.30mm) | 1 |
| 10***86 | Ring-Retaining | 1 |
144-3763 Cylinder Gp-Rotator
| 14***63 | Cylinder Group-Rotator | 1 |
| 14***22 | Kit-Seal | 1 |
145-5752 Cylinder Gp-Rotator
| 13***80 | Plug | 2 |
| 14***79 | Piston Group-Cylinder | 1 |
| 14***17 | Ring-Quad | 1 |
144-2488 Cylinder Gp-Rotator
| 03***92 | Seal; (126.59mm Id) | 2 |
| 14***88 | Cylinder Group-Rotator | 1 |
| 14***89 | Seal Set | 1 |
145-5740 Cylinder Gp-Rotator
| 14***71 | Ring-Backup | 1 |
| 14***70 | Piston Group-Cylinder | 1 |
| 14***15 | Quad-Ring | 1 |
144-6144 Cylinder Gp-Rotator
| 14***44 | Cylinder Group-Rotator | 1 |
| 14***00 | Kit-Seal | 1 |
144-4212 Cylinder Gp-Rotator
| 14***81 | Piston Group-Cylinder | 1 |
| 14***12 | Cylinder Group-Rotator | 1 |
| 14***13 | Kit-Seal | 1 |
144-3144 Cylinder Gp-Rotator
| 14***44 | Cylinder Group-Rotator | 1 |
| 14***52 | Kit-Seal | 1 |
145-5800 Cylinder Gp-Rotator
| 09***06 | Bolt-Socket Head; (M16x2x80-mm) | 12 |
| 14***60 | Piston | 1 |
| 14***19 | Ring-Quad | 1 |
145-3751 Cylinder Gp-Shear
| 03***25 | Ring-Backup | 2 |
| 08***48 | Ring | 1 |
| 09***31 | Seal-O-Ring | 1 |
144-3127 Cylinder Gp-Shear
| 09***77 | Setscrew-Socket | 1 |
| 14***27 | Cylinder Group-Shear | 1 |
| 14***31 | Ring-Retaining | 4 |
144-2752 Lines Gp-Cylinder
| 14***52 | Lines Group-Cylinder | 1 |
| 14***60 | Fitting | 2 |
| 14***88 | Connector | 2 |
144-3137 Lines Gp-Cylinder
| 09***70 | Bolt-Socket Hd; (M12 X 1.75 X 45) | 24 |
| 14***79 | Lockwasher | 24 |
| 14***73 | Lockwasher | 16 |
144-6136 Lines Gp-Cylinder
| 14***88 | Connector | 2 |
| 14***36 | Lines Group-Cylinder | 1 |
| 14***31 | Hose As | 2 |
144-3752 Lines Gp-Cylinder
| 09***70 | Bolt-Socket Hd; (M12 X 1.75 X 45) | 24 |
| 12***88 | Flange-Split | 28 |
| 14***16 | Plate | 2 |
144-4205 Lines Gp-Cylinder
| 14***05 | Lines Group-Cylinder | 1 |
| 14***88 | Connector | 2 |
| 14***32 | Fitting | 2 |
152-3699 Lines Gp-Cylinder
| 14***88 | Connector | 2 |
| 14***98 | Grommet | 2 |
| 15***17 | Hose As | 2 |
144-6029 Lines Gp-Cylinder
| 09***76 | Nut; (M14x2-Thd) | 16 |
| 14***60 | Fitting | 2 |
| 14***88 | Connector | 2 |
144-6045 Lines Gp-Rotator Cylinder
| 11***11 | Clamp | 1 |
| 14***73 | Lockwasher | 4 |
| 14***68 | Fitting | 2 |
144-6150 Lines Gp-Rotator Cylinder
| 14***56 | Valve Group-Pressure Control | 1 |
| 14***61 | Accumulator | 2 |
| 14***62 | Plate | 1 |
144-3773 Lines Gp-Rotator Cylinder
| 14***56 | Valve Group-Pressure Control | 1 |
| 14***61 | Accumulator | 2 |
| 14***68 | Fitting | 2 |
145-6217 Lines Gp-Rotator Cylinder
| 14***56 | Valve Group-Pressure Control | 1 |
| 14***61 | Accumulator | 2 |
| 14***72 | Plate | 2 |
144-4451 Lines Gp-Rotator Cylinder
| 14***56 | Valve Group-Pressure Control | 1 |
| 14***61 | Accumulator | 2 |
| 14***62 | Plate | 1 |
144-3151 Lines Gp-Rotator Cylinder
| 14***56 | Valve Group-Pressure Control | 1 |
| 14***61 | Accumulator | 2 |
| 14***62 | Plate | 1 |
144-1034 Lines Gp-Rotator Cylinder
| 14***34 | Lines Group-Rotator Cylinder | 1 |
| 14***56 | Valve Group-Pressure Control | 1 |
| 14***61 | Accumulator | 2 |
144-6131 Mounting Gp-Cylinder
| 14***31 | Fuel Filter; Sieve, Fuel Filter, Mounting Group-Cylinder | 1 |
| 14***32 | Plug; Dummy Plug, Plug, Pin As | 1 |
| 14***33 | Pin As, Chain | 1 |
144-3132 Mounting Gp-Cylinder
| 14***42 | Plate | 2 |
| 14***32 | Mounting Group-Cylinder | 1 |
| 14***33 | Pin As | 1 |
144-6025 Mounting Gp-Cylinder
| 14***69 | Screw | 4 |
| 14***25 | Mounting Group-Cylinder | 1 |
| 14***26 | Pin As | 1 |
144-4199 Mounting Gp-Cylinder
| 14***99 | Mounting Group-Cylinder | 1 |
| 14***00 | Pin As | 1 |
| 14***01 | Pin As | 1 |
152-3701 Mounting Gp-Cylinder
| 14***01 | Pin As | 1 |
| 14***02 | Spacer; (120.5x150x7-mm Thk) | 2 |
| 14***03 | Spacer; (120.5x150x18-mm Thk) | 2 |
144-2748 Mounting Gp-Cylinder
| 14***42 | Plate | 2 |
| 14***48 | Mounting Group-Cylinder | 1 |
| 14***49 | Pin As | 1 |
144-3747 Mounting Gp-Cylinder
| 14***42 | Plate | 2 |
| 14***47 | Mounting Group-Cylinder | 1 |
| 14***48 | Pin As | 1 |
144-1056 Valve Gp-Pressure Control
| 14***56 | Valve Group-Pressure Control | 1 |
| 14***88 | Connector | 2 |
| 17***54 | Valve Group-Relief | 2 |
149-4592 Valve Gp-Pressure Control
| 14***88 | Connector | 2 |
| 14***92 | Valve Group-Pressure Control | 1 |
| 17***45 | Valve Group-Relief | 2 |
165-8920 Valve Gp-Relief
| 16***20 | Valve Group-Relief | 1 |
| 17***12 | Seal-Bonded | 1 |
| 17***13 | Seal-O-Ring | 1 |
179-1745 Valve Gp-Relief
| 17***45 | Valve Group-Relief | 1 |
| 6V***06 | Seal-Bonded | 1 |
| 6V***80 | Seal-O-Ring; (20.35mm Id) | 1 |
179-1254 Valve Gp-Relief
| 17***54 | Valve Group-Relief | 1 |
| 6V***06 | Seal-Bonded | 1 |
| 6V***80 | Seal-O-Ring; (20.35mm Id) | 1 |
Service Equipment And Supplies
158-2129 Plate & Film Gp
| 10***45 | Film-Identification; (Cat) | 2 |
| 11***51 | Film-Stripe; (98 cm) | 0 |
| 14***36 | Film-Warning; (Flying Debris) | 2 |
164-7189 Plate & Film Gp
| 10***45 | Film-Identification; (Cat) | 2 |
| 11***51 | Film-Stripe; (98 cm) | 0 |
| 14***36 | Film-Warning; (Flying Debris) | 2 |
173-3784 Plate & Film Gp
| 10***45 | Film-Identification; (Cat) | 2 |
| 11***51 | Film-Stripe; (98 cm) | 0 |
| 14***36 | Film-Warning; (Flying Debris) | 2 |
164-7191 Plate & Film Gp
| 10***45 | Film-Identification; (Cat) | 2 |
| 11***51 | Film-Stripe; (98 cm) | 0 |
| 14***36 | Film-Warning; (Flying Debris) | 2 |
164-6368 Plate & Film Gp
| 10***45 | Film-Identification; (Cat) | 2 |
| 11***51 | Film-Stripe; (98 cm) | 0 |
| 14***36 | Film-Warning; (Flying Debris) | 2 |
164-7186 Plate & Film Gp
| 10***45 | Film-Identification; (Cat) | 2 |
| 11***51 | Film-Stripe; (98 cm) | 0 |
| 14***36 | Film-Warning; (Flying Debris) | 2 |
Work Tool Arrangement
178-6218 Shear Ar-Hydraulic
| 14***99 | Cylinder & Lines Group-Shear | 1 |
| 14***00 | Cylinder & Lines Group-Rotator | 1 |
| 17***84 | Plate & Film Group | 1 |
144-3062 Shear Ar-Hydraulic
| 14***74 | Cylinder & Lines Group-Shear | 1 |
| 14***75 | Cylinder & Lines Group-Rotator | 1 |
| 14***62 | Shear Ar-Hydraulic | 1 |
144-0972 Shear Ar-Hydraulic
| 14***72 | Shear Ar-Hydraulic | 1 |
| 14***73 | Housing Group-Shear | 1 |
| 14***74 | Cylinder & Lines Group-Shear | 1 |
152-3848 Shear Ar-Hydraulic
| 14***18 | Cylinder & Lines Group-Rotator | 1 |
| 15***86 | Edge Group-Cutting | 1 |
| 15***48 | Shear Ar-Hydraulic | 1 |
144-3065 Shear Ar-Hydraulic
| 14***79 | Cylinder & Lines Group-Shear | 1 |
| 14***80 | Cylinder & Lines Group-Rotator | 1 |
| 14***65 | Shear Ar-Hydraulic | 1 |
144-0958 Shear Ar-Hydraulic
| 14***58 | Shear Ar-Hydraulic | 1 |
| 14***59 | Housing Group-Shear | 1 |
| 14***60 | Cylinder & Lines Group-Shear | 1 |
144-0977 Shear Ar-Hydraulic
| 14***77 | Shear Ar-Hydraulic | 1 |
| 14***78 | Housing Group-Shear | 1 |
| 14***79 | Cylinder & Lines Group-Shear | 1 |
144-0987 Shear Ar-Hydraulic
| 14***87 | Shear Ar-Hydraulic | 1 |
| 14***88 | Housing Group-Shear | 1 |
| 14***89 | Cylinder & Lines Group-Shear | 1 |
158-4935 Shear Ar-Hydraulic
| 14***89 | Cylinder & Lines Group-Shear | 1 |
| 14***90 | Cylinder & Lines Group-Rotator | 1 |
| 15***35 | Shear Ar-Hydraulic | 1 |
144-0997 Shear Ar-Hydraulic
| 14***97 | Shear Ar-Hydraulic | 1 |
| 14***98 | Housing Group-Shear | 1 |
| 14***99 | Cylinder & Lines Group-Shear | 1 |
144-3071 Shear Ar-Hydraulic
| 14***89 | Cylinder & Lines Group-Shear | 1 |
| 14***90 | Cylinder & Lines Group-Rotator | 1 |
| 14***71 | Shear Ar-Hydraulic | 1 |
144-0963 Shear Ar-Hydraulic
| 14***63 | Shear Ar-Hydraulic | 1 |
| 14***65 | Housing Group-Shear | 1 |
| 14***66 | Cylinder & Lines Group-Shear | 1 |
144-3081 Shear Ar-Hydraulic
| 14***99 | Cylinder & Lines Group-Shear | 1 |
| 14***00 | Cylinder & Lines Group-Rotator | 1 |
| 14***81 | Shear Ar-Hydraulic | 1 |
155-4962 Shear Ar-Hydraulic
| 14***79 | Cylinder & Lines Group-Shear | 1 |
| 14***80 | Cylinder & Lines Group-Rotator | 1 |
| 15***62 | Shear Ar-Hydraulic | 1 |
Work Tools
209-0575 Bracket Gp-Mounting
| 09***49 | Washer; (22x60x6-mm Thk) | 1 |
| 10***96 | Bearing-Sleeve | 2 |
| 20***75 | Bracket Group-Mounting | 1 |
210-2310 Bracket Gp-Mounting
| 09***96 | Bolt; (M20x2.5-Thd) | 12 |
| 21***10 | Bracket Group-Mounting | 1 |
| 21***12 | Bracket As | 1 |
199-2418 Bracket Gp-Mounting
| 09***48 | Nipple, Grease | 2 |
| 09***79 | Nut; (M36x4.0 Thd) | 12 |
| 13***21 | Bearing-Sleeve; (130.24mm Od) | 2 |
144-0962 Edge Gp-Cutting
| 14***62 | Edge Group-Cutting | 1 |
| 14***87 | Screw-Flat Head | 4 |
| 14***98 | Screw-Flat Head; (M20x2.5x90-mm) | 2 |
144-3073 Edge Gp-Cutting
| 14***73 | Edge Group-Cutting | 1 |
| 14***87 | Screw-Flat Head | 8 |
| 14***36 | Tip-Wear | 1 |
144-3083 Edge Gp-Cutting
| 14***83 | Edge Group-Cutting | 1 |
| 14***65 | Screw-Flat Head; (M24x3x180mm) | 14 |
| 14***66 | Screw-Flat Head; (M24x3x160-mm) | 2 |
144-3067 Edge Gp-Cutting
| 14***15 | Screw-Flat Head; (M20x2.5x100-mm) | 2 |
| 14***67 | Edge Group-Cutting | 1 |
| 14***87 | Screw-Flat Head | 12 |
144-3064 Edge Gp-Cutting
| 14***87 | Screw-Flat Head | 2 |
| 14***64 | Edge Group-Cutting | 1 |
| 14***87 | Screw-Flat Head | 12 |
156-4985 Edge Gp-Cutting
| 14***15 | Screw-Flat Head; (M20x2.5x100-mm) | 1 |
| 14***87 | Screw-Flat Head | 13 |
| 14***78 | Lockwasher | 14 |
152-3686 Edge Gp-Cutting
| 14***89 | Screw-Flat Head | 9 |
| 15***86 | Edge Group-Cutting | 1 |
| 15***91 | Shim; (1mm Thk) | 4 |
178-6223 Edge Gp-Cutting
| 14***65 | Screw-Flat Head; (M24x3x180mm) | 13 |
| 14***66 | Screw-Flat Head; (M24x3x160-mm) | 3 |
| 14***96 | Shim; (1mm Thk) | 1 |
144-0991 Edge Gp-Cutting
| 14***91 | Edge Group-Cutting | 1 |
| 14***87 | Screw-Flat Head | 8 |
| 14***06 | Shim; (1-mm Thk) | 1 |
144-0981 Edge Gp-Cutting
| 14***81 | Edge Group-Cutting | 1 |
| 14***15 | Screw-Flat Head; (M20x2.5x100-mm) | 2 |
| 14***87 | Screw-Flat Head | 6 |
144-1001 Edge Gp-Cutting
| 14***01 | Edge Group-Cutting | 1 |
| 14***65 | Screw-Flat Head; (M24x3x180mm) | 13 |
| 14***66 | Screw-Flat Head; (M24x3x160-mm) | 2 |
144-0969 Edge Gp-Cutting
| 14***69 | Edge Group-Cutting | 1 |
| 14***15 | Screw-Flat Head; (M20x2.5x100-mm) | 2 |
| 14***87 | Screw-Flat Head | 8 |
144-0976 Edge Gp-Cutting
| 14***76 | Edge Group-Cutting | 1 |
| 14***87 | Screw-Flat Head | 2 |
| 14***87 | Screw-Flat Head | 6 |
160-7476 Edge Gp-Cutting
| 14***87 | Screw-Flat Head | 8 |
| 14***81 | Screw-Flat Head | 6 |
| 14***78 | Lockwasher | 14 |
Frequently asked questions
What carrier size does the Cat S40 coupler fit?
The S40 is built for 3-4 ton and 5-6 ton mini excavators; the two tonnage classes share the S40 name but differ in width, length, and pin diameter. It's also supplied as the pin-grabber coupler head on Cat's TRS4 (3-4 ton) and TRS6 (5-6 ton) tiltrotator systems.
What is the S40's rated lifting capacity?
Its integrated lifting hook is rated for 2000 kg (4409 lb) across both standard and LCS variants. Maximum hydraulic operating pressure at the coupler is about 300 bar (4351 psi), supplied by the host excavator's dedicated coupler circuit.
What's the difference between the standard S40 and the S40 LCS?
The standard S40 confirms a full lock with a visual verification rod the operator checks from the cab. The LCS version adds an electronic position sensor inside the lock cylinder that reports lock state digitally to the excavator's ECM on Next Generation mini excavators, giving a cab display indication instead of relying on the rod alone.
What S40 owners discuss
What wears out first on an S40 pin grabber coupler?
How does the hydraulic circuit reach the S40 coupler?
How reliable is the LCS lock-confirmation sensor on the S40 LCS variant?
Will an S40 fit buckets and attachments from other coupler brands or older Cat machines?
What's the correct way to check for a positive lock before digging?
What should I inspect on a used S40 before buying it?
Does the S40 need engine or transmission service like the excavator itself?
Compiled from owner and technician discussions across the industry — experiences vary by serial range and machine history.
Need a specific S40 part?
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