Caterpillarwork toolsnow blower

Caterpillar SR318

Maintenance schedule, common problems & OEM parts breakdown

The Caterpillar SR318 is a passive, carrier-mounted two-stage hydraulic snow blower work tool built for skid steer loaders, compact track loaders, multi-terrain loaders, and compact wheel loaders. It has no onboard engine, ECM, or undercarriage of its own; an auger and impeller move snow using hydraulic power drawn entirely from the host carrier's High Flow XPS circuit, roughly 125 L/min (33 gpm) at about 280 bar (4,061 psi). Operating weight runs around 452 kg (995 lb). The SR318 sits in Cat's SNB-family snow blower lineup alongside the SR115, SR118, SR121, and SR321, sized between the standard-flow SR121 and the wider high-flow SR321. It mounts to a broad range of carriers including the 226D/D3 through 299D2/D3 skid steer, track loader, and multi-terrain loader range, plus the 906K/M through 908K/M compact wheel loaders, and is offered with an optional performance package adding a non-metallic chute liner, side drift cutters, an impeller ingestion plate, and a chute cover plate.

Across spec-sheet revisions the SR318's core geometry, auger and impeller sizing, and 270-degree chute rotation have stayed consistent; what has changed is carrier compatibility, expanding from earlier B-series/C-series and early D-series/H-series host machines to the current D3-series and 900-series-M carrier lineup as Cat updated High Flow XPS availability across those platforms. Because it shares one operation and maintenance manual with its SR115/SR118/SR121/SR321 siblings, the SR318 is easy to misidentify against those family members if the carrier's hydraulic flow rating and auger width are not checked together. In the used and parts market this matters because the SR318 has no engine, filters, or emissions system to age out; its value and service life turn entirely on auger/impeller bearing condition, hydraulic motor health, and chain and cutting-edge wear, making it a straightforward, long-lived attachment for buyers running a High Flow XPS-equipped carrier for municipal or contractor snow removal work.

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 SR318 specifications

Engine

Power source

No onboard engine or ECM. The SR318 is a hydraulically driven work tool; its auger, impeller, chute rotation and deflector are powered and controlled through the carrier machine's hydraulic system and joysticks.

Weights

Operating weight (current generation)	496 kg (1,093 lb)
Operating weight (earlier generation)	450 kg (990 lb)
Ground pressure	Not published. The unit mounts to the carrier's quick coupler; it has no independent ground-contact rating.

Dimensions

Intake width (current generation)	1,614 mm (63.5 in)
Intake width (earlier generation)	1,854 mm (73 in)
Overall (transport) width (current generation)	1,877 mm (74 in)
Overall (transport) width (earlier generation)	1,918 mm (75.5 in)
Overall (transport) height (current generation)	1,843 mm (72.6 in)
Overall (transport) height (earlier generation)	1,582 mm (62.3 in)
Overall (transport) length (current generation)	1,020 mm (40 in)
Overall (transport) length (earlier generation)	1,209 mm (47.6 in)
Cutting height (current generation)	867 mm (34 in)
Cutting height (earlier generation)	813 mm (32 in)

Performance

Maximum throw distance (current generation)	12.2 m (40 ft)
Maximum throw distance (earlier generation)	13.7 m (45 ft)
Auger diameter (current generation)	457 mm (18 in)
Auger diameter (earlier generation)	406 mm (16 in)
Impeller/fan diameter (current generation)	635 mm (25 in)
Impeller/fan diameter (earlier generation)	517 mm (20 in)
Impeller/fan width (current generation)	222 mm (8.7 in)
Impeller/fan width (earlier generation)	279 mm (11 in)
Chute rotation (current generation)	270 degrees
Chute rotation (earlier generation)	180 degrees
Required carrier hydraulic flow (current generation)	100-120 L/min (26-33 gpm); carrier must have High Flow or High Flow XPS hydraulics
Required carrier hydraulic flow (earlier generation)	98-130 L/min (26-34 gpm); carrier must have high flow / high flow XPS option
Optimal hydraulic pressure (current generation)	200-280 bar (2,800-4,100 psi)
Gradeability / travel speed	Not applicable. This is a passive hydraulic work tool with no independent drivetrain; travel and grade performance depend entirely on the carrier machine.

Service capacities (summary)

Fuel tank	Not applicable. The attachment has no onboard engine and draws all power from the carrier machine.
Hydraulic system	No dedicated reservoir. Operates directly on the carrier machine's hydraulic circuit at the flow and pressure listed under Performance.
Engine oil / Cooling system	Not applicable. The attachment has no engine, transmission, or cooling system of its own.

Values vary by configuration, region, and serial range — confirm against your machine before planning transport or lifts.

SR318 fluids & capacities

System	Capacity	Recommended fluid
Engine, cooling, fuel, transmission, final drive, and axle systems	Not applicable	SR318 is a passive, hydraulically driven work tool with no onboard engine, coolant, fuel tank, transmission, or axle. It mounts to a skid steer or compact track loader carrier and runs off the carrier's hydraulic circuit.
Hydraulic system (drive circuit)	No onboard reservoir; SR318 carries no pump, motor oil sump, or tank of its own	Runs on the host carrier's hydraulic oil only. Requires a High Flow auxiliary circuit, optimal flow 125 L/min (33 US gpm) at 280 bar (4061 psi). Use only the oil grade and viscosity specified in the host machine's own Operation and Maintenance Manual; do not substitute a different spec for the attachment.
Auger bearing and left/right impeller bearings (grease fittings)	No fill capacity — grease each fitting until purge is visible at the seal; service every 30 hours	Multipurpose grease (MPGM) containing 3 to 5 percent molybdenum disulfide, conforming to MIL-M-7866. NLGI Grade 2 covers most operating temperatures; no separate cold-climate grade is called out.
Discharge chute chain and coupler chain	No fill capacity — wipe or brush on a light film across the chain	Clean engine oil (any on-hand engine oil is acceptable); no branded Cat oil is specified for this point.
Hydraulic cylinder rods (corrosion protection, off-season storage)	No fill capacity — light spray film on exposed chrome rod surfaces	Caterpillar 450 Rust Preventative Oil, applied to all chrome-plated cylinder rod surfaces and other exposed components before storage.

Capacities are refill values from factory literature — always fill to the dipstick/sight gauge, not the number.

Caterpillar SR318 maintenance schedule

Service interval	Tasks
Every 10 h	Walk around the attachment before each shift and check for bent auger flighting, missing or sheared drive pins, and a damaged cutting edge Inspect all hydraulic hoses, fittings, and quick-couplers for leaks, abrasion, or loose connections before hooking up to the carrier Grease the auger and impeller bearing points with MPGM (NLGI 2) grease at the start of each work week, or every 30 hours of use, whichever comes first Check skid shoe height and cutting-edge wear and adjust to hold correct ground clearance Verify the chute rotates through its full 270-degree sweep and the deflector answers the carrier joystick cleanly
Every 250 h	Lubricate the chute-rotation drive chain and coupler linkage with clean engine oil Inspect the chute-rotation gear and bearing for wear, binding, or excess play Check auger and impeller shaft bearing play and retighten mounting hardware to spec Inspect drift cutters, if equipped, and the bolt-on reversible cutting edge for wear; flip or replace as needed
Every 500 h	Inspect the hydraulic motor case drain and shaft seal for leakage Check the full length of hydraulic hoses and couplers for cracking, bulging, or chafing and replace any suspect hose Inspect the chute-rotation drive chain for stretch or damaged links and adjust tension or replace Torque-check all frame, mount plate, and quick-coupler bracket hardware
Every 1,000 h	Inspect auger and impeller shaft bearings and bushings for wear and replace if play exceeds allowable limits Flow-test the hydraulic motor to check for internal slip against the carrier's High Flow XPS output Inspect the chute-rotation gearbox internals for worn teeth or chain stretch beyond field adjustment range Inspect the mounting frame and coupler plate welds for cracking or fatigue
Every 2,000 h	Rebuild or exchange the hydraulic motor if flow testing shows performance below spec Replace auger and impeller shaft bearings, bushings, and seals as matched sets rather than piecemeal Replace the chute-rotation gear and drive chain if wear has reached the limit flagged at the 1000-hour inspection Inspect the full frame structure, auger flighting welds, and impeller housing for cracking or deformation
Every 2,500 h	Before off-season storage, cycle the chute and deflector through full range, then coat exposed chrome hydraulic rods with Cat 450 rust preventative Cap or plug open hydraulic couplers and block the attachment off the ground to protect the skid shoes and cutting edge Re-grease every fitting immediately before storage to purge moisture from the bearing points At pre-season startup, re-grease all points again, confirm the host carrier is set to High Flow XPS, and cycle every function before the first storm

Servicing the SR318 beyond the schedule

Predictive maintenance and fluid analysis

The SR318 has no reservoir or engine oil of its own, so predictive care means watching the host carrier's hydraulic fluid condition and filter service, since the attachment pulls the full 125 L/min at 280 bar through that circuit. Log case-drain flow and pressure readings seasonally to catch a wearing hydraulic motor before it fails mid-storm. Check grease color and consistency at the auger and impeller bearing points during weekly service; contamination or water intrusion there is the earliest warning sign of a bearing about to seize.

Corrective and common repairs

Bent auger flighting, sheared drive pins, and chewed cutting edges are the most common field repairs after curb strikes or buried debris. Use the reversible auger and impeller to clear jams without leaving the cab; if a jam persists, inspect the chute-rotation chain and gearbox for slipped or broken links. After any cutting-edge swap, recheck skid shoe height, and pressure-test hydraulic hoses and quick-couplers whenever the chute rotates sluggishly or stalls under load.

Overhaul and rebuild points

Major rebuild work centers on the auger and impeller shaft bearings, the chute-rotation gearbox and drive chain, and the hydraulic motor once flow testing shows internal slip against the carrier's rated output. Replace bearings, bushings, and chain as matched sets rather than one worn component at a time. Inspect the mounting frame and quick-coupler plate welds for fatigue cracking after repeated seasons of high-flow duty before returning the unit to service.

Seasonal and environment servicing

Before spring storage, cycle the chute and deflector through their full 270-degree range, then coat exposed chrome hydraulic rods with Cat 450 rust preventative and cap open couplers to keep moisture out. Block the attachment off the ground to protect the skid shoes and cutting edge from corrosion and ground contact. At pre-season startup, re-grease every point, confirm the host carrier is switched to High Flow XPS, and run the chute through its full sweep before the first job.

SR318 fault codes & troubleshooting

Code	Meaning	Likely cause	What to do
1004	Hydraulic oil filter restricted	Return-line hydraulic filter loading up on the host carrier while feeding the high-flow circuit that drives the auger and impeller	Check the filter restriction indicator, replace the hydraulic filter per the host machine's service interval, verify oil level and condition
1009	Hydraulic oil temperature above normal	Sustained high-flow operation working the two-stage auger/impeller in dense or wet snow pushes hydraulic oil temperature past the carrier's threshold	Let hydraulic oil cool, clear snow/ice packing from the cooler fins, confirm fan operation and oil level before resuming work
1201	Hydraulic filter restriction switch open circuit	Wiring or connector fault at the restriction switch on the host carrier's hydraulic filter housing	Inspect the switch connector and harness for damage or corrosion, repair wiring or replace the switch
4043 / 4044	Hydraulic oil temperature sensor shorted to ground (4043) or open circuit (4044)	Damaged wiring or a failed temperature sensor in the host carrier's hydraulic tank or return line	Inspect sensor wiring and connector, test sensor resistance against spec, replace the sensor if out of range
5281 / 5282 / 5291 / 5292	Loader auxiliary valve forward (A) or reverse (B) solenoid supply circuit open or shorted to ground	Damaged wiring, connector corrosion, or a failed solenoid coil in the auxiliary high-flow circuit that powers the attachment	Check the solenoid connector and harness for continuity, test coil resistance, repair wiring or replace the solenoid
5507 / 5508	Auxiliary valve spool position sensor open or shorted to ground (5507), or shorted to power (5508)	Sensor or wiring fault on the auxiliary spool that meters hydraulic flow to the attachment	Inspect spool sensor wiring, verify sensor output against calibration spec, replace the sensor if faulty
5513	Implausible auxiliary sensor state versus auxiliary command, logged as a stuck spool or pressure relief valve event	Auxiliary valve spool sticking under the load of driving the two-stage snow blower, or contamination in the high-flow circuit	Cycle the auxiliary control, inspect the valve spool for sticking or contamination, clean or service the valve, check system pressure
3251-4	Hi-flow hydraulic circuit fault, shown in CID-FMI format on CAN-based skid steer/CTL instrument clusters when the high-flow circuit is engaged	Hi-flow pressure sensor or wiring issue reacting to the demand of a high-flow attachment such as the snow blower	Check the hi-flow pressure sensor and wiring, inspect the hi-flow valve spool for sticking or contamination, verify filters and oil level

Codes and remedies are general guidance for this model family — always confirm with diagnostic tooling and your dealer before major repairs.

SR318 attachments & work tools

Work tool type / class

SR318 is a two-stage hydraulic snow blower attachment for skid steer loaders, multi-terrain loaders, compact track loaders, and compact wheel loaders. It uses a rotating auger to feed snow into a fan-style impeller for high-volume throw, sized for a mid-size intake tier within Cat's SR11x/SR3xx snow blower line (SR115/SR118/SR121 standard-flow tier vs SR318/SR321 high-flow tier).

Carrier / coupler compatibility

Factory-listed carriers span the D/D3-series compact loaders (226D/D3 through 299D2/D3) and 906K/M-908K/M compact wheel loaders. Mounting uses the carrier's standard skid-steer-style quick-coupler plate, no special adapter documented beyond the normal SSL/CTL/CWL attachment plate.

Hydraulic kit / flow requirement

SR318 requires the machine's high-flow hydraulic package, specifically the high-flow XPS option; it will not run on a base standard-flow circuit. Rated hydraulic flow is about 125 L/min (33 gpm) at roughly 280 bar (4,060 psi) operating pressure; on XHP/XE carriers it runs in high-flow XPS mode. Some older listings show lower standard-flow figures (80 L/min / 230 bar) but those values belong to the smaller SR115/SR118/SR121 tier, not SR318 — verify hydraulic package with your dealer before ordering.

Auger and impeller

High-strength auger flighting resists bending under load, and both the auger and impeller are hydraulically reversible so the operator can clear obstructions without leaving the cab. The impeller is fan-style for smoother, more continuous material flow across varying snow conditions.

Chute and discharge controls

Chute rotation covers 270 degrees, letting the operator direct discharge to the front or either side to avoid blowback. Chute, auger, impeller, and deflector are all hydraulically actuated and run off the carrier's joysticks with plug-n-play wiring, no extra harness needed. Compact wheel loader configurations use an offset chute for better operator visibility and full range of motion.

Cutting edge and ground engagement

A bolt-on, reversible cutting edge extends wear life and simplifies field replacement. Adjustable skid shoes set cutting-edge height to suit surface and job conditions (pavement vs gravel).

Optional performance package

An optional package adds a non-metallic chute liner to resist snow buildup and freeze-up, side drift cutters to help push through high or dense snowbanks, an impeller ingestion plate to limit snow thrown before it reaches the chute, and a chute cover plate to stop snow from falling back onto the blower housing.

Access and safety features

A wide, grated access step with large-profile serrations improves boot traction, paired with a chute-mounted grab handle for stable entry and exit around the attachment. The rotating discharge chute uses non-binding gearing to prevent jamming during operation.

All SR318 assemblies by section

Every catalogued assembly group for the Caterpillar SR318. Open an assembly to preview the parts inside — full OEM part numbers are available in Heavy Parts AI.

Electrical System

261-4419 Wiring Gp-Work Tool

10***67	Washer-Hard; (7.2x25x2-mm Thk)	2
10***02	Kit-Receptacle; (2-Pin)(Engine Sensor Wiring Harness)	3
11***15	Relay As; (12-Volt)(Junction Box)	2
12***78	Locknut; (M6x1-Thd)	4

See all parts with full part numbers in Heavy Parts AI →

281-3790 Wiring Gp-Work Tool

10***67	Washer-Hard; (7.2x25x2-mm Thk)	2
11***15	Relay As; (12-Volt)(Junction Box)	2
12***78	Locknut; (M6x1-Thd)	4
22***15	Harness As-Work Tool; (Connecting)	1

See all parts with full part numbers in Heavy Parts AI →

Frame And Body

290-8925 Deflector Gp-Snowblower

03***55	Locknut; (5/16-18-Thd)(Marked X)	6
12***78	Locknut; (M6x1-Thd)	2
13***85	Rivet-Pop	7
1D***72	Bolt-Carriage; (1/2-13x5.5-In)	6

See all parts with full part numbers in Heavy Parts AI →

290-8888 Deflector Gp-Snowblower

03***55	Locknut; (5/16-18-Thd)(Marked X)	6
12***78	Locknut; (M6x1-Thd)	2
13***85	Rivet-Pop	7
1D***72	Bolt-Carriage; (1/2-13x5.5-In)	6

See all parts with full part numbers in Heavy Parts AI →

290-8915 Frame Gp-Snowblower

1K***72	Locknut Horn To Guard	8
21***22	Support Group-Work Tool	2
21***23	Frame As	1
21***25	Impeller As	1

See all parts with full part numbers in Heavy Parts AI →

290-8924 Frame Gp-Snowblower

1K***72	Locknut Horn To Guard	7
21***82	Impeller As	1
21***83	Guard As	1
21***90	Frame As	1

See all parts with full part numbers in Heavy Parts AI →

290-8919 Frame Gp-Snowblower

1K***72	Locknut Horn To Guard	9
21***75	Frame As	1
21***80	Impeller As	1
21***81	Guard As; (Impeller Motor)	1

See all parts with full part numbers in Heavy Parts AI →

213-7222 Support Gp-Work Tool

21***22	Support Group-Work Tool	1
28***93	Tube As	1
28***97	Pad As; (Stabilizer)	1
28***17	Pin-Hitch	1

See all parts with full part numbers in Heavy Parts AI →

Hydraulic System

283-9595 Cylinder Gp-Hydraulic

28***95	Cylinder Group-Hydraulic	1
4K***77	Nut-Self Locking	1
7J***04	Seal-O-Ring (Id=7.65mm)	2
9S***07	Plug, O-Ring Flush - Includes Item 15	2

See all parts with full part numbers in Heavy Parts AI →

290-8920 Hydraulic Ar-Snowblower

28***95	Cylinder Group-Hydraulic	1
29***20	Hydraulic Ar-Snowblower	1
29***97	Manifold Group-Control	1
29***70	Lines Group-Connecting	1

See all parts with full part numbers in Heavy Parts AI →

290-8926 Hydraulic Ar-Snowblower

28***95	Cylinder Group-Hydraulic	1
29***26	Hydraulic Ar-Snowblower	1
29***97	Manifold Group-Control	1
29***68	Lines Group-Connecting	1

See all parts with full part numbers in Heavy Parts AI →

295-4866 Hydraulic Ar-Snowblower

28***95	Cylinder Group-Hydraulic	1
29***97	Manifold Group-Control	1
29***66	Hydraulic Ar-Snowblower	1
29***71	Lines Group-Connecting	1

See all parts with full part numbers in Heavy Parts AI →

290-8916 Hydraulic Ar-Snowblower

28***95	Cylinder Group-Hydraulic	1
29***16	Hydraulic Ar-Snowblower	1
29***97	Manifold Group-Control	1
29***69	Lines Group-Connecting	1

See all parts with full part numbers in Heavy Parts AI →

295-4867 Hydraulic Ar-Snowblower

28***95	Cylinder Group-Hydraulic	1
29***97	Manifold Group-Control	1
29***67	Hydraulic Ar-Snowblower	1
29***72	Lines Group-Connecting	1

See all parts with full part numbers in Heavy Parts AI →

295-4871 Lines Gp-Connecting

10***03	Plate-Cover	1
14***48	Fitting As; (Quick Disconnect, Male)	1
14***49	Fitting As; (Quick Disconnect, Female)	1
14***15	Connector As	4

See all parts with full part numbers in Heavy Parts AI →

295-4869 Lines Gp-Connecting

10***03	Plate-Cover	1
14***15	Connector As	4
14***36	Adapter; (Straight) (-6 Orb X -6 Orfs)	2
14***41	Connector Group	4

See all parts with full part numbers in Heavy Parts AI →

295-4870 Lines Gp-Connecting

10***03	Plate-Cover	1
14***15	Connector As	4
14***36	Adapter; (Straight) (-6 Orb X -6 Orfs)	2
14***41	Connector Group	4

See all parts with full part numbers in Heavy Parts AI →

295-4872 Lines Gp-Connecting

10***03	Plate-Cover	1
14***48	Fitting As; (Quick Disconnect, Male)	1
14***49	Fitting As; (Quick Disconnect, Female)	1
14***15	Connector As	4

See all parts with full part numbers in Heavy Parts AI →

295-4868 Lines Gp-Connecting

10***03	Plate-Cover	1
14***15	Connector As	4
14***36	Adapter; (Straight) (-6 Orb X -6 Orfs)	2
14***41	Connector Group	4

See all parts with full part numbers in Heavy Parts AI →

295-2597 Manifold Gp-Control

10***08	Kit-Seal; (Solenoid Valve, Quick Steer)	1
19***27	Kit-Seal; (Pressure Reducing Valve)	1
19***95	Valve Group-Solenoid; (Swing/Extension)	2
22***87	Coil	4

See all parts with full part numbers in Heavy Parts AI →

227-5496 Motor Gp-Gerotor

17***46	Kit-Seal	1
22***96	Motor Group-Gerotor	1
3J***54	Packing,Preformed Part Of Kit P/N 5r***27	1
7R***67	Seal-Dust	1

See all parts with full part numbers in Heavy Parts AI →

213-7192 Motor Gp-Gerotor

17***46	Kit-Seal	1
21***92	Motor Group-Gerotor	1
22***72	Key	1
3J***54	Packing,Preformed Part Of Kit P/N 5r***27	1

See all parts with full part numbers in Heavy Parts AI →

227-5510 Motor Gp-Gerotor

17***46	Kit-Seal	1
22***10	Motor Group-Gerotor	1

See all parts with full part numbers in Heavy Parts AI →

216-0795 Motor Gp-Gerotor

17***46	Kit-Seal	1
21***95	Motor Group-Gerotor	1
22***72	Key	1
3J***54	Packing,Preformed Part Of Kit P/N 5r***27	1

See all parts with full part numbers in Heavy Parts AI →

212-4588 Motor Gp-Gerotor -Auger, 67-In

17***46	Kit-Seal	1
21***88	Motor Group-Gerotor; -Auger, 67-In	1

See all parts with full part numbers in Heavy Parts AI →

212-4589 Motor Gp-Gerotor

17***46	Kit-Seal	1
21***89	Motor Group-Gerotor	1
22***72	Key	1

See all parts with full part numbers in Heavy Parts AI →

212-4587 Motor Gp-Gerotor -Deflector

1B***14	Key-Woodruff	1
1G***32	Kit-Seal	1
21***87	Motor Group-Gerotor; -Deflector	1
7R***43	Washer	7

See all parts with full part numbers in Heavy Parts AI →

179-9223 Valve Gp-Check

17***23	Valve Group-Check; -Steering Pump	1
3J***07	Seal Valve Assembly To; Seal- Tube Assembly To Logic Valve	1
4J***77	Seal - O - Ring (11.23mm Od)	1

See all parts with full part numbers in Heavy Parts AI →

Service Equipment And Supplies

261-4423 Plate & Film Gp

12***56	Film; (Warning) (No Step) (On Top Of Hood Behind Cab On Each Side) (On Each Fender Flare)	1
15***62	Film-Information; (Tie-Down Location)	2
22***45	Film-Warning; (Crush Hazard, Stay Back)	2
22***30	Film-Warning; (Flying Debris, Stay Back, U.S.)	2

See all parts with full part numbers in Heavy Parts AI →

290-8921 Plate & Film Gp

12***56	Film; (Warning) (No Step) (On Top Of Hood Behind Cab On Each Side) (On Each Fender Flare)	1
15***62	Film-Information; (Tie-Down Location)	2
22***45	Film-Warning; (Crush Hazard, Stay Back)	2
22***30	Film-Warning; (Flying Debris, Stay Back, U.S.)	2

See all parts with full part numbers in Heavy Parts AI →

290-8917 Plate & Film Gp

12***56	Film; (Warning) (No Step) (On Top Of Hood Behind Cab On Each Side) (On Each Fender Flare)	1
15***62	Film-Information; (Tie-Down Location)	2
22***45	Film-Warning; (Crush Hazard, Stay Back)	2
22***30	Film-Warning; (Flying Debris, Stay Back, U.S.)	2

See all parts with full part numbers in Heavy Parts AI →

290-8927 Plate & Film Gp

12***56	Film; (Warning) (No Step) (On Top Of Hood Behind Cab On Each Side) (On Each Fender Flare)	1
15***62	Film-Information; (Tie-Down Location)	2
22***45	Film-Warning; (Crush Hazard, Stay Back)	2
22***30	Film-Warning; (Flying Debris, Stay Back, U.S.)	2

See all parts with full part numbers in Heavy Parts AI →

261-4426 Plate & Film Gp

12***56	Film; (Warning) (No Step) (On Top Of Hood Behind Cab On Each Side) (On Each Fender Flare)	1
15***62	Film-Information; (Tie-Down Location)	2
22***45	Film-Warning; (Crush Hazard, Stay Back)	2
22***30	Film-Warning; (Flying Debris, Stay Back, U.S.)	2

See all parts with full part numbers in Heavy Parts AI →

Work Tool Arrangement

286-0728 Snowblower Ar -85-In

26***19	Wiring Group-Work Tool	1
26***26	Plate & Film Group	1
28***28	Snowblower Ar; -85-In	1
29***19	Frame Group-Snowblower	1

See all parts with full part numbers in Heavy Parts AI →

286-0724 Snowblower Ar -67-In

28***90	Bracket, Wiring Group-Work Tool	1
28***24	Snowblower Ar; -67-In	1
29***23	Drive Group-Snowblower	1
29***24	Frame Group-Snowblower	1

See all parts with full part numbers in Heavy Parts AI →

286-0726 Snowblower Ar -85-In

28***90	Bracket, Wiring Group-Work Tool	1
28***26	Snowblower Ar; -85-In	1
29***18	Drive Group-Snowblower	1
29***19	Frame Group-Snowblower	1

See all parts with full part numbers in Heavy Parts AI →

286-0725 Snowblower Ar -73-In

28***90	Bracket, Wiring Group-Work Tool	1
28***25	Snowblower Ar; -73-In	1
29***14	Drive Group-Snowblower	1
29***15	Frame Group-Snowblower	1

See all parts with full part numbers in Heavy Parts AI →

286-0727 Snowblower Ar -73-In

26***19	Wiring Group-Work Tool	1
26***23	Plate & Film Group	1
28***27	Snowblower Ar; -73-In	1
29***15	Frame Group-Snowblower	1

See all parts with full part numbers in Heavy Parts AI →

Work Tools

290-8914 Drive Gp-Snowblower

01***41	Setscrew-Socket	2
02***87	Fitting-Grease; (Universal Joint)	2
21***44	Sprocket Group; (16-Teeth, Impeller)	1
21***45	Bearing Group-Self-Aligning	3

See all parts with full part numbers in Heavy Parts AI →

294-7388 Drive Gp-Snowblower

01***41	Setscrew-Socket	2
02***87	Fitting-Grease; (Universal Joint)	2
21***44	Sprocket Group; (16-Teeth, Impeller)	1
21***45	Bearing Group-Self-Aligning	3

See all parts with full part numbers in Heavy Parts AI →

290-8923 Drive Gp-Snowblower

01***41	Setscrew-Socket	2
02***87	Fitting-Grease; (Universal Joint)	2
21***44	Sprocket Group; (16-Teeth, Impeller)	1
21***45	Bearing Group-Self-Aligning	3

See all parts with full part numbers in Heavy Parts AI →

290-8918 Drive Gp-Snowblower

01***41	Setscrew-Socket	2
02***87	Fitting-Grease; (Universal Joint)	2
21***44	Sprocket Group; (16-Teeth, Impeller)	1
21***45	Bearing Group-Self-Aligning	3

See all parts with full part numbers in Heavy Parts AI →

SR318 serial number reference

The PIN/serial tag on the SR318 is a riveted metal plate mounted on the attachment frame near the quick-coupler mounting plate, readable while the unit is still attached to the host loader. The serial reads as a 3-character alphanumeric prefix followed by a 5-digit sequence number; the prefix identifies the production/serial block, the digits identify the individual unit within that block. The SR318 is a passive hydraulic attachment with no engine of its own, so the prefix only tracks the attachment build block, not any engine or host-machine fitment.

Prefix	Identifies	Notes
SRW	SR318 production block, mid-cycle (from roughly 2007-on)	Documented as an SR318 serial block in parts-catalog indexing and matched by an actual sold unit carrying this prefix dated years later, showing the block stayed in use over an extended run. No engine on this attachment - it runs off the host skid steer/compact track loader's hydraulics, so there is no engine-fitment split by prefix.
PHG	Early SR318 production block (from roughly 2004)	Shown as the earliest SR318 serial block in parts-catalog indexing, predating the SRW block. Thinly documented - confirm with dealer before using for warranty or parts-fit decisions.
SNB	Shared serial block, SR117 / SR118 / SR121 / SR318 / SR321 family	SNB00001-up is the applicable range on the electrical-system service manual covering this whole snow-blower group, SR318 included alongside its siblings. Because it spans five models it may only apply to a subset of SR318 units or a specific harness revision rather than the whole model run. Confirm with dealer for a given unit.
J3B	Recent/current SR318 production	Matched to an actual low-hour SR318 unit at a Cat dealer, consistent with current production. Confirm with dealer whether this is the active running block.

Frequently asked questions

What engine does the Caterpillar SR318 use?

None. The SR318 is a passive attachment with no onboard engine, fuel tank, or ECM. It runs entirely off the host carrier's hydraulic system, requiring the High Flow XPS circuit delivering roughly 125 L/min (33 gpm) at about 280 bar (4,061 psi).

What is the operating weight of the Caterpillar SR318?

Cat's current spec sheet lists the SR318 at about 452 kg (995 lb). Some older listings and family-wide figures range from roughly 424 to 461 kg (932 to 1,015 lb) across the SR115-SR321 lineup, so confirm the exact figure for your unit's build against the dealer spec sheet.

What replaced the Caterpillar SR318?

No documented successor has been identified. The SR318 remains part of Cat's current High Flow XPS snow blower lineup alongside the larger SR321, itself part of the SNB family that succeeded the earlier SBA-family snow blowers; verify current availability with your Cat dealer.

What SR318 owners discuss

What causes the auger to stop suddenly while blowing snow, and is that normal?

Shear pins in the auger driveline are meant to break when the auger hits a curb, manhole cover, frozen chunk, or buried gravel. That's protective behavior, not a defect. Replace with the pin grade specified for this unit; don't substitute a harder bolt, since that just transfers the shock load into the gearbox and bearings instead of the pin. If pins keep shearing in clean snow with no obstructions, check skid shoe height and auger-to-frame clearance before assuming a gearbox fault. Have your dealer verify gearbox end-play if pins keep breaking after shoe adjustment is corrected.

Will running this blower on a carrier with more hydraulic flow than it needs cause damage?

Yes, if the mismatch is significant. Feeding a hydraulic attachment substantially more flow than its motor is rated for overheats the oil, stresses seals, and can take out the auger/impeller motor. This unit is built around the High Flow-class circuits Cat lists for it; a base standard-flow carrier will undersupply it, while a much larger flow/pressure circuit than the tool's rating risks overheating from the other direction. Match the carrier's rated flow and pressure to the attachment's spec rather than assuming more flow is always better. Have your dealer verify carrier flow and pressure settings before running an SR318 you haven't used on that machine before.

Why won't the discharge chute rotate, or why is it slow and jerky?

Common causes on hydraulically rotated snow-blower chutes: packed ice or snow jammed in the rotation ring restricting movement, a dry or poorly lubricated rotation ring/chain increasing friction, trapped air in the rotation circuit after a hose or coupler was disconnected, or a sticking solenoid or dirty electrical connector at the manifold that shares oil pressure for rotation and deflector control. Clear obvious ice or packed snow first, then cycle the function a few times to bleed trapped air before condemning the motor or valve. Have your dealer verify the manifold and wiring if the chute still won't move after clearing ice and cycling.

What wears fastest on the auger and cutting edges, and what should I watch for?

The auger flighting and impeller take the abrasive wear, especially on gravel work, aggressive skid shoe settings, or ice-glazed pavement. Bent or nicked auger edges throw snow unevenly and increase vibration; a bowed auger shaft or worn end bearings show up as play when you rock the auger/impeller by hand with the shear pins pulled. On new asphalt or chip-seal, running shoes low so steel edges bite during hard cold snaps can peel or ravel the surface; running shoes slightly higher and accepting a thin packed-snow base is the safer setting there. Have your dealer verify auger shaft and bearing play if you feel resistance or side-play with the pins removed.

How should skid shoes be set, and does the surface type matter?

Yes. Shoes set too low on gravel dig in, feed rock into the auger, and cause repeated shear-pin failures; running them slightly proud of a gravel or unimproved surface cuts both scraping and pin breakage. On concrete or asphalt a lower shoe setting gives a cleaner scrape, and poly shoes are preferred over steel where surface marking or wear matters. Reversible, adjustable shoes let you flip or shim them as they wear instead of replacing early. Recheck shoe height whenever the surface type changes or after any pin failure, since a bent shoe bracket changes running clearance.

Do the SR115 through SR321 snow blowers all mount and run the same way since they share one manual?

No. They share the same basic two-stage auger/impeller layout and one service manual, but each size step in the family is scaled for a different flow, pressure, and carrier weight class. The SR318 sits toward the larger end and is specified for High Flow-class circuits rather than base standard flow. Don't carry a hydraulic motor, hose, or flow figure verified on a sibling model over to the SR318; confirm the rating plate on the specific unit and match it to the carrier's actual flow class rather than going by family reputation. Have your dealer verify the flow/pressure rating on your specific unit against your carrier before first use.

What should I check before buying a used SR318?

Pull the shear pins and rock the auger and impeller by hand; resistance or looseness points to worn bearings or a tired gearbox drive. Inspect the auger flighting and cutting edges for bends, nicks, or heavy wear from gravel work, and check the skid shoes for wear and correct mounting hardware. Look at the chute and rotation ring for cracks, ice-pack damage, or a chain/ring that binds when turned by hand. Check hydraulic hoses and the quick-attach coupler plate and faces for cracking, leaks, or wear that would prevent a tight, drip-free hookup. Cycle the chute rotation and deflector on a compatible high-flow carrier before purchase, since electrical or manifold faults only show up under power. Have your dealer verify hydraulic motor condition and coupler wear on a pre-purchase inspection before committing to a used unit.

Compiled from owner and technician discussions across the industry — experiences vary by serial range and machine history.

Need a specific SR318 part?

Search live OEM part data, check fitment, and cross-reference alternatives with Heavy Parts AI.

Search parts in the app