Question 1

What carrier excavator does the Cat CR3 fit?

Accepted Answer

The CR3 is sized for Cat 302.5-class mini excavators. It pins directly to the boom and stick and runs its crushing or shearing cylinders off the carrier's auxiliary hydraulic circuit rather than an onboard power source.

Question 2

What is the CR3's operating weight?

Accepted Answer

Not documented in any public factory spec sheet for this exact SKU. As the entry model in Cat's CR-series, it is built lighter than the CR20 and up to suit a mini-excavator carrier - confirm the exact figure from the tool's nameplate or with a Cat dealer before matching it to a carrier's lift capacity.

Question 3

What replaced the Cat CR3?

Accepted Answer

No confirmed direct successor is documented for the CR3 by name. Caterpillar's current attachment catalog covers this size and function with multi-processor (MP-series) crusher-jaw and shear-jaw tools, but no source ties the CR3 to a specific replacement SKU - check current equivalents with a Cat dealer.

Question 4

What wear pattern should I expect on the CR3's jaw sets, and how do owners get more life out of them?

Accepted Answer

Concrete and rebar are abrasive on the jaw teeth and cutting edges. Expect steady wear on the crusher teeth and shear blade edges with regular use, with rounding at the tips first. Keep hardsurfacing buildup current on the crusher jaw wear zones - once the parent steel starts wearing instead of the hardface layer, the jaw weakens structurally, not just cosmetically. On the shear jaw, rotate and shim the blades on schedule and re-torque blade bolts regularly; loose blades chip and gall faster than tight ones. A coordinated operating style - positioning the jaw square on the material and cycling off relief pressure rather than holding on it - cuts wear noticeably versus operators who muscle through every pass.

Question 5

The jaws feel loose and the tool clatters or bangs when opening and closing - is that normal?

Accepted Answer

No - that is the classic sign of pin-and-bushing wear at the jaw pivots. As clearance builds up, the moving jaw takes on an exaggerated angle under load, which puts extra stress on the pins, the cylinder rod eye, and the housing itself. Left unchecked it snowballs into cylinder and structural wear, not just a noisy attachment. Grease the pivots daily when the tool is in regular use and check pin-to-bushing clearance on a set schedule; swap bushings before the pins themselves start to wear, since bushings are the cheaper, faster fix. Persistent knock after a bushing change points to a worn pin or an out-of-round bore - have your dealer verify pin and bore condition before returning the tool to service.

Question 6

Can I swap between crusher jaw and shear jaw on the same CR3 body, and how involved is it?

Accepted Answer

Yes, that is the point of the combination design - one housing and cylinder set accepts either a crusher jaw or a shear jaw. Newer quick-change multi-processor style tools let a single operator swap jaws with no special tools in well under half an hour; the CR3's design predates that fast-change hardware, so treat a jaw swap as a shop job involving pins, retaining hardware, and a lifting device rather than a cab-operated function. Budget real shop time for it and do not attempt it hanging from the boom. Confirm the exact swap procedure and any required hardware for your specific CR3 with your dealer, since published documentation on this attachment is thin compared to the mainline CR-series crushers.

Question 7

Why does the crusher feel weak or slow to close on my carrier even though the tool itself looks fine?

Accepted Answer

This is almost always a hydraulic supply mismatch, not a worn tool. Crusher/shear attachments need the carrier's auxiliary circuit flow and relief pressure to land inside the tool's rated window - too little flow gives slow, weak cycles, and too much pressure risks blowing seals or overstressing the structure over time. On a mini excavator carrier this usually comes down to running the tool off the factory-matched auxiliary plumbing rather than an aftermarket circuit, and confirming the machine's relief setting has not drifted. Contaminated hydraulic oil is the other repeat offender - dirt in the fluid scores the tool's internal valve and cylinder seals and mimics a flow problem. Have your dealer verify the carrier's auxiliary relief pressure and flow output against the tool's rating before chasing the attachment itself.

Question 8

What should I check on the coupler and mounting side, not just the tool itself?

Accepted Answer

Play at the coupler is one of the most common complaints with any pin-on demolition tool in this class. Worn coupler pins or bores let the whole attachment rock, which accelerates wear everywhere downstream - the tool's own pivots, the cylinder rod eye, and the stick and boom pins. Inspect coupler lock engagement and pin-bore wear on the same interval as the tool's own pivots, not as an afterthought. If you run a quick coupler rather than a direct pin-on mount, confirm the coupler is rated for the tool's weight and shock loading; undersized couplers on crusher/shear tools show up in wear complaints more than almost any other cause. Have your dealer verify coupler lock and pin-bore condition if you notice any looseness at the mount.

Question 9

What causes cylinder leaks on these attachments, and is it a shop fix or a DIY job?

Accepted Answer

Two things account for most cylinder seal failures on crusher/shear tools: contaminated hydraulic oil scoring the rod and seals, and shock loading from operators slamming the jaws into material instead of positioning and squeezing. Weeping at the rod seal or pivot cylinder is the early warning sign; do not run it to a full seal failure, since that dumps oil under pressure right at the jaw pivot where hands and hoses sit close by. Keep the carrier's return-line filter on its service interval, since dirty oil is the single biggest driver of premature seal wear on these tools. A rod seal kit is a reasonable field repair if you are set up for it, but a scored or pitted rod means machining or rod replacement. Have your dealer verify rod condition before you simply re-seal it, or you will end up doing the job twice.

Question 10

What should I inspect before buying a used CR3?

Accepted Answer

Walk the same list experienced buyers use on any pin-on crusher/shear attachment. Check jaw and blade wear - remaining hardface or edge material, chipping or cracking at the teeth. Check pin-and-bushing play at every pivot, including the coupler mount. Check cylinder condition for weeping seals, scoring on the exposed rod, and even extension side to side. Check the housing and frame for cracks or prior weld repairs around the pivot bosses and cylinder mounts, since those are the high-stress points that show fatigue first. Ask for service records showing greasing frequency and any jaw or bushing replacements - a tool with documented bushing swaps was probably maintained, one with none at high hours probably was not. Confirm the tool's hydraulic flow and pressure rating matches whatever carrier you will actually run it on, since a tool matched to a bigger machine's circuit will underperform or overstress a smaller one. Have your dealer verify structural condition and cylinder integrity on anything showing visible weld repairs before putting it back into service.

Configuration	Dual-purpose jaw tool: the factory parts breakdown shows both a crusher jaw arrangement and a shear jaw arrangement built around a common housing, cylinder, and mounting bracket, so one base unit can be set up as a concrete crusher or a demolition shear.
Length, jaw opening, jaw depth	Not documented in publicly available factory literature for this exact model.

Rotation	No rotator components appear in the factory parts breakdown for this tool, unlike Caterpillar's larger CR-family concrete crushers (which carry a top-mounted continuous rotator). This points to a fixed, non-rotating jaw head, though this is inferred from the parts structure rather than stated directly in a spec sheet.
Crushing force / shearing force	Not documented in publicly available factory literature for this exact model.

Fuel, engine oil, coolant	Not applicable. The tool has no engine or fluid reservoir of its own; all hydraulic fluid is supplied and serviced through the host excavator's system.
Hydraulic flow and pressure requirements	Not documented in publicly available factory literature for this exact model.

System	Capacity	Recommended fluid
Engine crankcase (with filter)	Not applicable	The CR3 is a pin-on, carrier-mounted crusher/shear work tool for Cat excavators. It carries no engine of its own, so no crankcase fill applies.
Cooling system	Not applicable	No engine or radiator on the tool; no coolant system exists to service.
Fuel tank	Not applicable	No fuel system on the tool; the crusher/shear is unpowered on its own and runs purely off carrier hydraulics.
Transmission / powertrain compartments	Not applicable	No powertrain on the tool; it has no drivetrain of its own.
Final drives	Not applicable	No final drives fitted; the tool is a carrier-mounted attachment with no travel function of its own.
Axles / differentials	Not applicable	No axles or differentials fitted.
Hydraulic system (crushing/shear cylinder circuit)	No dedicated onboard reservoir. The CR3 draws oil directly from the host excavator's hydraulic tank and pump circuit through quick-disconnect lines; it has its own cylinder, relief valve, and connecting-line groups but no separate fluid capacity of its own. A published flow/pressure rating specific to the CR3 could not be confirmed from available factory literature; it sits below the CR20 in the crusher line, so expect lower flow and pressure than the CR20's rating - confirm exact figures against the carrier-matching chart for this unit.	Follow the carrier excavator's own fluid chart, since the tool shares that machine's oil with no separate reservoir. Cat's factory-fill and top-up choice is Cat HYDO Advanced multigrade hydraulic oil; acceptable commercial alternates are oils meeting Cat ECF-1-a, ECF-2, or ECF-3 performance, or Cat TO-4/TO-4M where the carrier calls for it, with a minimum zinc additive level of about 0.09 percent (900 ppm). Viscosity grade is picked from the carrier excavator's own ambient-temperature chart, not from a CR3-specific chart, since the tool has no independent reservoir.
Grease - crusher/shear pins, bushings, and mounting bracket joints	Spec only, no fill volume given. Grease each fitting with a hand or power grease gun until fresh grease purges visibly at the joint; repeat at the machine's standard daily/shift greasing interval or per the carrier excavator's work-tool greasing schedule.	Cat Multipurpose Grease (Cat MPGM), an NLGI 2 extreme-pressure grease with a molybdenum disulfide (moly) additive, for the crushing-arm and shear-arm pins, bushings, and mounting-bracket joints. In sub-zero or arctic ambient conditions, step down to a softer NLGI-grade multipurpose EP grease per dealer recommendation to keep the grease pumpable and maintain film strength at the pin joints.

Service interval	Tasks
Every 50 h	Grease all pivot pins and bushings on the jaw and cylinder mounts before each shift. Inspect hydraulic hoses, fittings, and cylinder glands for weeping or damage. Check crusher teeth or shear blade edges for cracking, chipping, or excess wear. Verify mounting pins and coupler retention hardware are secure and properly locked. Clean concrete dust and debris from pivot joints and grease zerks before greasing.
Every 250 h	Torque-check coupler and mounting bolts to spec. Inspect cylinder rods for scoring, pitting, or seal weep. Measure jaw wear plates and shim or replace them once wear limits are reached. Inspect housing welds and pin bosses for early cracking.
Every 500 h	Sample and check the condition of the carrier's hydraulic oil, since the CR3 shares that circuit. Measure pivot pin and bushing clearance and log the trend against prior readings. Replace crusher teeth or shear blades that are beyond safe wear limits. Inspect cylinder mounting pins and retaining hardware for wear or looseness. Check the housing and jaw structure for cracking after heavy rebar-cutting duty.
Every 1,000 h	Reseal cylinders showing rod scoring, drift, or external leakage. Replace pins and bushings that have exceeded measured wear tolerance. Inspect pin bores for elongation or out-of-round wear. Confirm the carrier's relief valve setting still matches the tool's rated pressure. Repaint exposed housing and jaw surfaces to protect against corrosion.
Every 2,000 h	Fully strip the jaw and pivot assembly for inspection. Check housing bore ovality and recondition or bush out-of-tolerance bores. Replace pin and bushing sets as complete matched sets rather than individually. Crack-check load-bearing welds and structural castings. Rebuild both cylinders with new seal kits regardless of visible condition.
Every 4,000 h	Strip the housing completely and recondition or replace all pin bores. Replace all pins, bushings, and cylinder seal kits as a full set. Dye-penetrant or magnetic-particle inspect the housing and jaw castings for fatigue cracking before return to service. Repaint and re-torque the entire tool to factory assembly spec.

Caterpillar CR3

Caterpillar CR3 specifications

Engine

Weights

Dimensions

Performance

Service capacities (summary)

CR3 fluids & capacities

Caterpillar CR3 maintenance schedule

Servicing the CR3 beyond the schedule

Predictive Maintenance & Fluid Analysis

Corrective & Common Repairs

Overhaul & Rebuild Points

Seasonal & Environment Servicing

CR3 attachments & work tools

Crusher jaw set

Shear jaw set

Mounting / coupler interface

Hydraulic kit / arrangement

Wear and cutting edges

Guarding and safety decals

Category placement (general Cat crusher/shear line)

All CR3 assemblies by section

CR3 serial number reference

Frequently asked questions

What CR3 owners discuss

Need a specific CR3 part?

09***06	Bolt-Socket Head; (M16x2x80-mm)	12
15***50	Housing Group-Crusher	1
15***84	Plate	1
15***59	Pin	2

15***51	Cylinder & Lines Group-Crusher	1
15***28	Cylinder Group-Crusher	1
15***11	Mounting Group-Cylinder	1
15***12	Lines Group-Cylinder	1

09***88	Setscrew	2
15***28	Cylinder Group-Crusher	1
15***60	Rod	1
15***61	Clamp	1

15***94	Coupler As-Quick Disconnect; (Female)(Quick Disconnect)	1
15***95	Fitting As; (Quick Disconnect, Male)	1
16***37	Hose As	2
16***50	Lines Group-Connecting	1

10***48	Hose As; (Nom 06, L=700mm)	1
12***69	Hose As	1
15***52	Fitting	2
15***65	Swivel Group	1

15***63	Pin	2
15***49	Lockwasher	4
15***11	Mounting Group-Cylinder	1
15***17	Retainer	2

13***45	Seal Kit; (Includes Parts Marked J)	1
15***67	Block	1
15***90	Valve Group-Relief	1
15***20	Valve Group-Relief	1

15***44	Film-Warning; (Flying Debris)	2
15***52	Film-Warning; (Stay Back)	2
15***53	Film-Information; (Read Omm)	2
15***54	Film-Warning; (Alert)(Safety Alert)	2

14***94	Shear Ar-Hydraulic	1
15***51	Cylinder & Lines Group-Crusher	1
15***05	Edge Group-Cutting	1
16***37	Housing Group-Shear	1

09***96	Bolt; (M20x2.5-Thd)	4
17***69	Bracket Group-Mounting	1
17***70	Bracket As	1
8T***23	Washer-Plated; (22x35x3.5-mm Thk)	2

15***49	Screw-Flat Head; (M10x1.5x25-mm)	2
15***95	Shim; (0.3-mm)	4
15***96	Shim; (0.5-mm)	2
15***97	Shim; (1-mm Thk)	2

15***53	Tooth & Cutting Edge Group	1
15***66	Arm As-Crushing	1
15***67	Arm As-Crushing	1
15***15	Bushing	2

15***04	Arm As-Cutting	1
15***05	Edge Group-Cutting	1
15***32	Arm As-Cutting	1
15***15	Bushing	2

15***53	Tooth & Cutting Edge Group	1
15***54	Shim; (0.3-mm)	4
15***55	Shim; (0.5-mm)	2
15***56	Shim; (1-mm Thk)	2

09***96	Bolt; (M20x2.5-Thd)	4
17***52	Bracket Group-Mounting	1
18***75	Bracket As	1
8T***23	Washer-Plated; (22x35x3.5-mm Thk)	2

Prefix	Identifies	Notes
6EZ	CR3 hydraulic concrete crusher, crusher-jaw arrangement	Covers the crusher-jaw configuration from 6EZ00001 up. This is a stick-mounted hydraulic attachment with no engine of its own; it runs off the carrier's hydraulic system. Fits the Cat 302.5 mini hydraulic excavator (later 302.5C), the smallest carrier in the Cat concrete-crusher lineup, sized below the CR20/CR28/CR35/CR50 family used on 320B-through-375-class carriers. Documented in the same factory parts manual as the 7HZ shear-jaw arrangement.
7HZ	Shear-jaw arrangement built on the same CR3 base housing and mounting bracket	Covers the shear-configuration jaw set from 7HZ00001 up, documented in the same factory manual as the 6EZ crusher-jaw unit and fitted to the same 302.5 mini excavator carrier. The factory manual heading references this shear unit as S3 Shear alongside CR3 Crusher, so confirm the exact model tag on the PIN plate with a dealer if identifying the unit from parts alone.