Caterpillar PR-275
Maintenance schedule, common problems & OEM parts breakdown
The Caterpillar PR-275 is a self-propelled cold planer, also called a pavement profiler, built by CMI Corporation and sold under the Cat nameplate following Caterpillar's 1985 manufacturing agreement with CMI. It belongs to the original Cat PR-series lineup alongside the PR-75, PR-105, PR-450, and PR-750B, the machines that marked Caterpillar's entry into the worldwide cold-planer market. Engine identity for the PR-275 traces to a Cat 3304 or 3306 diesel depending on the unit built; sources disagree on which was primary and no PR-275-specific spec sheet confirms displacement or rated output. Operating weight, milling width, and cutting depth are not documented anywhere found for this exact nameplate, so treat any such figure quoted for it as unverified until checked against the machine's own serial tag. Production ran through the mid-1980s into the 1990s. The RT suffix seen on this model (PR-275-RT) points to a rubber-tired chassis configuration, consistent with how this CMI/Cat product family was named; no track-mounted PR-275 variant is documented. No direct successor nameplate is documented for the PR-275 specifically.
Documentation for the PR-275 is thinner than for its PR-105 and PR-450 siblings, so changes across its production run are not well mapped. The two engine references recorded for it, the 3304 and the 3306, suggest either a running change partway through production or a customer-selectable option rather than a clean generational split of the kind seen on other Cat models from this era. As a CMI-built machine wearing an early Cat badge, it sits at the seam between CMI's own Roto-Mill cold-planer line and Caterpillar's later in-house cold-planer engineering, which is part of why it turns up more often in used-equipment auctions and salvage yards than in any current parts catalog. Its cutting-drum toolholders and teeth cross into the broader CMI Roto-Mill design shared with the PR-105 and PR-450, so parts sourcing for a PR-275 today usually runs through that shared toolholder lineage rather than a PR-275-only parts book. For owners and rebuilders it is a genuine but scarce find: budget time to track down the original CMI operation and maintenance manual and parts catalog for the actual serial number, since general spec databases do not cover this nameplate reliably.
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 PR-275 specifications
Engine
| Engine model | Not documented in available specification sources for this early Cat cold planer. No source ties a specific engine make or model to the PR-275 by name — do not assume a sibling PR-series engine. Verify with the original Cat spec sheet or a dealer. |
| Gross/net power | Not documented in available sources for this model. |
| Displacement / cylinders | Not documented in available sources for this model. |
| Emissions tier | Pre-Tier (mechanical-era machine); no certified emissions tier published. |
Weights
| Operating weight | Approximately 17,237 kg (38,000 lb) per the one available spec listing for this model. Not cross-checked against a second independent listing — treat as approximate and confirm before transport planning. |
| Shipping weight | Not documented in available sources for this model. |
| Ground pressure | Not published for this model. |
Dimensions
| Standard operating length | Approximately 5.74 m (18 ft 10 in), single-source figure. |
| Standard operating width | Approximately 2.44 m (8 ft 0 in), single-source figure. |
| Standard operating height | Approximately 2.90 m (9 ft 6 in), single-source figure. |
| Wheelbase / track gauge | Not documented in available sources for this model. |
| Ground clearance | Not published for this model. |
Performance
| Travel speed | Not documented in available sources for this model. |
| Cutting width / depth | Not reliably documented for this specific model — cutting width/depth figures found could not be confirmed as belonging to the PR-275 rather than a similarly numbered sibling, so they are omitted rather than guessed. |
| Gradeability | Not published for this model. |
Service capacities (summary)
| Fuel tank | Not documented in available sources for this model. |
| Hydraulic system | Not documented in available sources for this model. |
| Engine oil | Not documented in available sources for this model. |
| Cooling system | Not documented in available sources for this model. |
Values vary by configuration, region, and serial range — confirm against your machine before planning transport or lifts.
PR-275 fluids & capacities
| System | Capacity | Recommended fluid |
|---|---|---|
| Engine crankcase (with filter) | Not published for the PR-275 in available literature — the OMM refill chart for this serial range (prefix 6RC) is not accessible online; capacity varies by the diesel engine actually fitted (verify against the plate/serial before servicing) | Cat DEO (Diesel Engine Oil), SAE grade selected per ambient-temperature chart in the Cat multigrade oil recommendations — exact grade not documented for this unit |
| Cooling system | Not documented for the PR-275. | Cat ELC (Extended Life Coolant) or Cat DEAC (Diesel Engine Antifreeze/Coolant), full-strength or 50/50 premix per climate — no PR-275-specific mixing note found |
| Fuel tank | Not documented for the PR-275; sibling models in the same early cold-planer lineup range widely (PR-105 approx. 212 L / 56 gal up to PR-450 approx. 757 L / 200 gal), so PR-275 capacity cannot be interpolated reliably — verify on the machine's tank or OMM | No. 2-D diesel fuel per Cat fuel specification; low-sulfur/ULSD per emissions-era requirement if applicable to the specific serial |
| Transmission/powertrain compartment | Not documented for the PR-275. | Cat TDTO (Transmission and Drive Train Oil) — viscosity grade not confirmed for this model |
| Final drives (each) | Not documented for the PR-275; cold planers of this era typically carry separate final-drive/gearbox fills at each track or rotor drive, but no per-side figure is available. | Cat TDTO or Cat FDAO (Final Drive Axle Oil) depending on drive configuration — not confirmed for this unit |
| Hydraulic system and tank | Not documented for the PR-275. | Cat HYDO (Hydraulic Oil) — viscosity grade per ambient-temperature chart, exact grade not confirmed for this model |
| Grease (spec only) | n/a — grease points serviced per lubrication schedule, no reservoir capacity applies | Cat multipurpose grease (NLGI grade per climate, typically NLGI 2 for general service, NLGI 1 or 0 in cold climates) per standard Cat lubrication recommendations |
Capacities are refill values from factory literature — always fill to the dipstick/sight gauge, not the number.
Caterpillar PR-275 maintenance schedule
| Service interval | Tasks |
|---|---|
| Every 10 h |
|
| Every 250 h |
|
| Every 500 h |
|
| Every 1,000 h |
|
| Every 2,000 h |
|
| Every 4,000 h |
|
Servicing the PR-275 beyond the schedule
Predictive Maintenance & Fluid Analysis
Since PR-275 predates ECM diagnostics, predictive maintenance leans on oil sampling and visual and audible inspection. Sample engine oil (3304 or 3306 diesel) at each oil change for wear metals given fuel and dust ingestion from milling debris. Sample hydraulic oil for the drum-drive and propel circuits, since particulate contamination is the top failure driver on this abrasive-duty machine. Track coolant condition given water-spray-system splash-back near the engine bay. No fault-code history exists, so watch gauges, listen for drum bearing or chain noise, and log oil analysis trends to catch cutting-drum and hydraulic pump wear early.
Corrective & Common Repairs
Most repairs trace to the cutting drum and conveyor, the two highest-wear systems on a mechanical-era profiler like this. Expect frequent toolholder and cutting-tooth replacement from asphalt and aggregate abrasion, plus drum bearing and seal repair from water and fines intrusion. Hydraulic hose and cylinder repairs are common on the leveling, depth-control, and conveyor-swing circuits. The Cat 3304 or 3306 diesel is otherwise conventional mechanical-injection era; corrective work centers on fuel system cleanliness and cooling system upkeep rather than any electronic control repairs, since this generation carries none.
Overhaul & Rebuild Points
Major rebuild work centers on the cutting-drum assembly: drum shaft, bearings, and drive coupling wear from continuous milling loads. Hydraulic pump and motor overhaul is the next largest job, since this rubber-tired profiler runs everything, propel, drum drive, conveyor, and steering, off engine-driven hydraulics with no electronic assist. Engine overhaul on the 3304 or 3306 follows conventional mechanical-diesel practice: injector pump and nozzle service, turbo inspection where fitted, and top-end work at high hours. Frame and moldboard wear from asphalt spoil also drives structural rebuild on high-hour units.
Seasonal & Environmental Servicing
Cold-planer duty is hardest on the water-spray system and cutting drum in freezing conditions; drain spray lines and pumps fully before winter storage to prevent cracking. Warm the 3304 or 3306 diesel per cold-start procedure before engaging the drum drive, since mechanical-injection engines of this era need extended glow or ether-assisted starts in low temperatures. Flush accumulated slurry and fines from the conveyor and drum housing between jobs and seasonally, since packed asphalt debris accelerates corrosion on the rubber-tired chassis and undercarriage components over an idle season.
PR-275 attachments & work tools
Cutting rotor and bit pattern
The PR-275 carries a single fixed-width milling rotor typical of Caterpillar's original cold-planer line, with bit holders arranged around the drum in a staggered pattern for even cut depth. Exact drum width and bit count are not published for this specific model online; treat as machine-specific and confirm against the rotor tag or dealer records.
Cutting tools / bit types
Standard tooling for this class is a conical carbide-tipped bit seated in a replaceable holder, sized for asphalt milling rather than concrete. Heavier-duty bit options exist across the wider Cat cold-planer range, but no PR-275-specific bit variant is documented; assume standard asphalt-duty tooling unless the machine tag states otherwise.
Moldboard / side plate containment
Cold planers of this size and era use hydraulically actuated front moldboard and side plates around the cutting chamber to contain milled material and control edge finish, with raise/lower/float functions. No PR-275-specific plate width or actuation detail is documented; this is a class-typical function, not a confirmed PR-275 spec.
Water spray / dust suppression system
Self-propelled cold planers in this class typically carry an integrated water tank and spray system to cool cutting bits and control dust during milling. Tank capacity and spray-bar configuration are not documented for the PR-275 specifically; verify with dealer records or the machine's operation manual.
Primary discharge conveyor
Removed material is typically carried off the cutting chamber by a front- or side-discharge conveyor on machines of this class, loading directly into a hauling truck. No PR-275-specific conveyor length, fold, or slew option is confirmed in available documentation.
Undercarriage configuration
Cat's early cold-planer lineup (PR-75, PR-105, PR-275, PR-450, PR-750B) included both track and wheeled undercarriage variants across the family, though which configuration(s) the PR-275 itself shipped with is not confirmed in available sources. Treat undercarriage type as a factory-build detail to verify against the specific unit's serial tag (prefix 6RC).
Operator station / guarding
Machines in this size class commonly offered a canopy or cab option with a raised operator platform for chamber visibility during milling. No PR-275-specific canopy, cab, or lighting package is documented; treat as a possible factory option pending dealer confirmation rather than a verified spec.
All PR-275 assemblies by section
Every catalogued assembly group for the Caterpillar PR-275. Open an assembly to preview the parts inside — full OEM part numbers are available in Heavy Parts AI.
Pavement Profiler
43590 3-Pump Drive Gear Box Ratio 1 : 1.196
| 4***0 | 3-Pump Drive Gear Box Ratio 1:1.196 | 1 |
961150 Attachment : Air Conditioner Assy.
| 96***50 | Attachment: Air Conditioner Assembly. | 1 |
961143 Attachment : Cab Heater Assembly
| 96***43 | Attachment: Cab Heater Assembly | 1 |
969065 Attachment : Turn Signal Assembly
| 96***65 | Attachment: Turn Signal Assembly | 1 |
96478 Attachment : Weld Fixture Assy. (Double)
| 9***8 | Attachment: Weld Fixture Assembly. | 1 |
965009 Auxiliary Hydraulic System
| 96***09 | Auxiliary Hydraulic System | 1 |
965025 Auxiliary Power Supply Hydraulic System
| 96***25 | Auxiliary Power Supply Hydraulic System | 1 |
96818 Averaging Ski Assembly
| 9***8 | Averaging Ski Assembly | 1 |
961101 Cab Components Assembly
| 96***01 | Cab Components Assembly | 1 |
964001 Central Lube System Assembly
| 96***01 | Central Lube System Assembly | 1 |
979026 Central Lubrication J-Box Assembly
| 97***26 | Central Lubrication J-Box Assembly | 1 |
96901 Console And Controls Assembly
| 9***1 | Console And Controls Assembly | 1 |
969020 Console Panel Electrical Assembly
| 96***20 | Console Panel Electrical Assembly | 1 |
9640001 Cross Slope Assembly
| 96***01 | Cross Slope Assembly | 1 |
965023 Cross Slope Hydraulic System
| 96***23 | Cross Slope Hydraulic System | 1 |
96401 Cutter Assembly (Complete)
| 9***1 | Cutter Assembly | 1 |
965051 Cutter Drive Hyd. System
| 96***51 | Cutter Drive Hydraulic. System | 1 |
969017 Dash, Instrument Panel Assembly
| 96***17 | Dash, Instrument Panel Assembly | 1 |
962018 Decal Group
| 96***18 | Decal Group | 1 |
969001 Electrical Control Group
| 96***01 | Electrical Control Group | 1 |
Electrical Schematic (Pr275)
| P***5 | Electrical Schematic | 1 |
961201 Elevation Scale Assembly
| 96***01 | Elevation Scale Assembly | 1 |
93486 Flywheel Assembly
| 9***6 | Flywheel Assembly | 1 |
965027 Fuel Line System
| 96***27 | Fuel Line System | 1 |
413524 Gear Box Assembly, Ratio 24.45 : 1
| 41***24 | Gear Box Assembly, Ratio 24.45:1 | 1 |
965003 Hydraulic Filters Group
| 96***03 | Hydraulic Filters Group | 1 |
965008 Hydrostratic Case Drain System
| 96***08 | Hydrostratic Case Drain System | 1 |
965008 Hydrostatic Case Drain System
| 96***08 | Hydrostratic Case Drain System | 1 |
L.F. & R.R. Steering Cable & Pulley Assembly
96844 L.H. Elevation Sensor Mounting
| 9***4 | L.H. Elevation Sensor Mounting | 1 |
965024 Line Sensor Hydraulic Assembly
| 96***24 | Line Sensor Hydraulic Assembly | 1 |
96201 Mainframe Assembly
| 9***1 | Mainframe Assembly | 1 |
969027 Motor Speed Indicator Assembly
| 96***27 | Motor Speed Indicator Assembly | 1 |
965026 Park Brake Hydraulic System
| 96***26 | Park Brake Hydraulic System | 1 |
96501 Power Pack Assembly
| 9***1 | Power Pack Assembly | 1 |
Pr-275 Pavement Profiler
965002 Prefill Hydraulic System
| 96***02 | Prefill Hydraulic System | 1 |
R.F. & L.R. Steering Cable & Pulley Assy.
969016 Remote Instrument Panel Assembly
| 96***16 | Remote Instrument Panel Assembly | 1 |
961001 Shipping Group
| 96***01 | Shipping Group | 1 |
96778 Steering Actuation Assy.
| 9***8 | Steering Actuation Assembly. | 1 |
961704 Steering Box Assembly
| 96***04 | Steering Box Assembly | 1 |
965022 Steering Hydraulics System
| 96***22 | Steering Hydraulics System | 1 |
965004 Suction Hydraulic System
| 96***04 | Suction Hydraulic System | 1 |
96601 Tank & Cowling Assy.
| 9***1 | Tank & Cowling Assembly. | 1 |
965005 Valves And Manifolds Assembly
| 96***05 | Valves And Manifolds Assembly | 1 |
96816 Walking Beam Assembly -- L.H. & R.H. Side
| 9***6 | Walking Beam Assembly | 1 |
963001 Water Spray Assembly
| 96***01 | Water Spray System Assembly | 1 |
963001 Water Spray System Assembly
| 96***01 | Water Spray System Assembly | 1 |
96322 Wheel Drive Assembly
| 9***2 | Wheel Drive Assembly | 1 |
965052 Wheel Drive Hydraulics Assy.
| 96***52 | Wheel Drive Hydraulics Assembly. | 1 |
19065 Windshield Wiper Motor Assembly
| 1***5 | Windshield Wiper Motor Assembly | 1 |
Frequently asked questions
What engine powers the Caterpillar PR-275?
Documented sources tie the PR-275 and PR-275-RT to a Cat 3304 or 3306 diesel, depending on the unit built. Sources don't agree on which was primary or if it was a customer-selectable option. No independent PR-275-specific engine spec sheet has surfaced, so verify displacement and rated output against the machine's own tag data rather than assuming either engine by default.
What is the operating weight of the Caterpillar PR-275?
No confirmed operating weight figure exists for this specific nameplate. Cold planers of this size and era from the CMI/Cat PR-series generally fall in the multi-tonne self-propelled milling class, but published weight, milling width, and cutting depth figures specific to the PR-275 have not turned up in any factory spec sheet or dealer catalog. Verify against the machine's serial tag or a dealer parts lookup.
What replaced the Caterpillar PR-275?
No documented one-to-one successor exists. The PR-275 was part of Caterpillar's original CMI-built PR-series (PR-75, PR-105, PR-275, PR-450, PR-750B) launched after Caterpillar's 1985 manufacturing agreement with CMI Corporation. Caterpillar's cold-planer line later moved on to PM-series and then PC-series machines, but no source ties any specific later model to the PR-275 as a direct replacement.
What PR-275 owners discuss
What do people who actually run a PR-275 say is the biggest headache with this machine?
What engine does the PR-275 actually run, and are there quirks to watch for?
How does the undercarriage and track wear on a machine like this?
What goes wrong with the drum drivetrain and cutting teeth over time?
Is the water spray system really as troublesome as people say?
What hydraulic issues show up most often on this type of profiler?
What should you check before buying a used PR-275?
Compiled from owner and technician discussions across the industry — experiences vary by serial range and machine history.
Need a specific PR-275 part?
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