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Caterpillar HH700

Maintenance schedule, common problems & OEM parts breakdown

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The Cat HH700 is a single-grip harvester head, a hydraulically powered forestry work tool with no engine or hydraulic tank of its own. It mounts on a host excavator carrier and draws all power through that carrier's auxiliary hydraulic circuit. Factory documentation pairs the HH700 specifically with the Cat 320C hydraulic excavator, a roughly 20-tonne class carrier fitted with a dedicated high-flow auxiliary control arrangement for the head. In the field the HH700 fells standing timber, delimbs the stem with opposed feed roller arms and delimb knives, and bucks it to length using an integrated retractable bar-and-chain saw, all in one continuous processing cycle run from the carrier cab. Caterpillar service literature documents the head from the early 2000s onward, tracked under a single serial prefix.

What sets the HH700 apart in its own service history is a factory running change to how it hangs on the carrier: early production used a yoke-style hanger mount, while a later run switched to a bolted lower-link mount, a straightforward production update rather than a fix for a specific failure. The HH700 is also a separate product line from Caterpillar's smaller harvester head family, which carries its own control system and serial history; the two lines should not be treated as interchangeable or blended for specs. That distinction matters in the used and parts market today, since a logging contractor sourcing a used HH700 needs a carrier already fitted, or fittable, with the matching auxiliary hydraulic control kit, and needs to confirm which mount style a given head carries before pairing it with a boom and stick.

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 HH700 specifications

Engine

Power sourceNo onboard engine. The HH700 is an excavator-mounted harvester head; it runs entirely off the host carrier's engine and hydraulic system through an auxiliary high-flow control circuit.
Documented host carrierFactory installation documentation ties the HH700 to the Cat 320C hydraulic excavator (20-tonne class) fitted with a high-flow auxiliary control valve arrangement for the harvester-head circuit. Other excavator sizes may be listed by dealers, but only the 320C pairing is confirmed in factory service literature.

Weights

Operating weightNot published in verifiable factory or dealer spec sheets for this model. Secondary listings disagree by a wide margin and cannot be cross-checked, so no figure is given here — confirm exact head weight and host-carrier counterweight/boom requirements with your dealer.
Shipping weightNot documented in available sources.

Dimensions

Transport dimensionsNot documented in available factory or dealer literature for this model. Ask your dealer for head width, length and swing/rotation envelope sized to your host carrier's boom and stick.
Maximum cutting/felling diameterNot confirmed from a reliable factory source; do not rely on unverified third-party listings for this figure.

Performance

Feed roller speed (maximum)151 ± 1 RPM, factory test spec for the feed roller drive, checked with a photo-tachometer.
Harvester-head hydraulic circuit relief pressure28000 ± 500 kPa (4060 ± 72 psi) factory setting for the head's own hydraulic relief valve (governs rotator and attachment circuit maximum pressure).
Host excavator auxiliary line relief pressure13100 ± 700 kPa (1900 ± 100 psi) factory setting on the host 320C excavator's auxiliary control valve that supplies the HH700 attachment circuit.

Service capacities (summary)

Engine oil, fuel, coolantNot applicable. The head has no engine; all engine-related service points and capacities follow the host carrier's own schedule.
Hydraulic systemThe HH700 shares the host carrier's hydraulic tank and oil; no separate hydraulic reservoir capacity is published for the head itself.
Saw chain lubricationUses a dedicated bar-and-chain oil supply for the felling/delimbing saw. No specific reservoir capacity is published for this model.

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

HH700 fluids & capacities

SystemCapacityRecommended fluid
Saw chain lubrication (chain-oil tank/reservoir mounted on the head)Not published in available documentation for this exact tank. The HH700 shares its lubrication-circuit design with the rest of the Cat harvester-head line: oil flows from an onboard lubrication tank to lubricate the saw chain and the feed-roller-arm pivots. No liter/gallon fill figure for the HH700's own tank turned up in public sources — confirm the exact fill volume against the OMM or with your dealer.Bar-and-chain type lubricating oil sized for saw-chain service. Cat does not publish one dedicated branded chain-oil product name for this head in accessible documentation; the OMM specifies an approved viscosity grade by ambient temperature and will accept either mineral or rapidly biodegradable chain oil. Verify the exact brand callout and cold-weather grade with your dealer or the OMM lubricant chart.
Grease points (rotator, feed-roller-arm pivots, delimbing-knife/knife-arm pivots, and other pin joints)No bulk fill capacity — these are grease-gun service points serviced per shift/interval, not a reservoir system.Cat Multipurpose Grease meeting Caterpillar's grease specification (MPGM). Cat Advanced 3Moly Grease — NLGI 2, lithium-complex base with 3% molybdenum disulfide, rated for moderate speed/load pivot applications across roughly -20 to 40 deg C (-4 to 104 deg F) — is the typical Cat-branded product used at this duty level, but the specific NLGI grade called out in the HH700 OMM itself was not confirmed in public sources. Verify grade and any cold-climate substitution with your dealer.
Hydraulic systemNo independent tank on the head. The HH700 has no onboard hydraulic pump or reservoir — it operates entirely on the carrier excavator's hydraulic system (e.g., Cat 320/320C carriers it is designed to mount on) and draws from that machine's own hydraulic tank and oil supply. There is no separate hydraulic-oil capacity to publish for the attachment itself.Same hydraulic fluid as specified for the host carrier excavator (typically Cat HYDO Advanced or the fluid called out in the carrier's own OMM). No separate fluid specification is published for the harvester head, since it shares the carrier's oil.

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

Caterpillar HH700 maintenance schedule

Service intervalTasks
Every 10 h
  • Check saw chain tension and bar oil flow before starting production cutting.
  • Inspect saw bar rails, chain, and nose sprocket/bearing for damage or binding.
  • Grease the rotator, feed-roller arm pivots, delimb-knife pivots, and holding-arm pins.
  • Inspect hydraulic hoses and fittings at the rotator and saw box for chafing, cracking, or weeping.
  • Check feed roller spikes for wear and grip on wet or frozen stems.
  • Listen for unusual noise or stiffness from the rotator under load.
Every 50 h
  • Check delimb knife edges for dullness or chipping; sharpen or replace as needed.
  • Check feed-roller-arm and delimb-knife pivot pins and bushings for freeplay.
  • Clean the saw bar groove and inspect drive chain wear.
  • Verify bar-and-chain oil supply and lubrication flow rate.
  • Cycle the rotator through full rotation and check for stiffness or backlash.
  • Check mounting hardware at the yoke or bolted lower-link mount for looseness.
Every 250 h
  • Inspect the rotator bearing and gear train for wear.
  • Check the head's own hydraulic circuit relief pressure against the factory setting and adjust if needed.
  • Check the host carrier's auxiliary line relief pressure against the factory setting.
  • Renew feed roller spikes or teeth that have rounded off.
  • Inspect the saw motor, drive sprocket, and nose bearing for wear; replace if worn.
  • Inspect hose routing across the rotator and saw box; replace any hose showing wear.
Every 500 h
  • Tear down and inspect feed-roller-arm and delimb-knife linkage pins and bushings; renew worn parts.
  • Inspect and service the holding-arm pivots and cylinder.
  • Check saw bar rails for straightness; replace if bent or worn beyond limits.
  • Inspect the chain-oil supply system for contamination or restricted flow.
  • Check rotator mount hardware torque and condition, yoke or bolted lower-link style.
  • Inspect the control box and wiring harness routed to the carrier cab for damage.
Every 1,000 h
  • Inspect and rebuild the rotator bearing and seals as needed.
  • Inspect the saw motor and rebuild or replace if worn beyond service limits.
  • Overhaul the feed-roller drive motors and gearboxes.
  • Replace hoses and fittings on high-flex routing at the rotator, saw box, and tilt joint.
  • Re-torque and inspect all major structural mounting pins and bushings.
  • Recalibrate head hydraulic relief and carrier auxiliary flow/pressure settings with dealer support.
Every 2,000 h
  • Complete a full teardown and rebuild of the head, renewing major structural pins, bushings, and wear plates.
  • Flush and reseal the head's hydraulic circuit components; renew seals throughout.
  • Replace the saw bar, chain, and drive components as a set if approaching service limits.
  • Inspect and renew feed-roller arm and delimb-knife structural castings for wear or cracking.
  • Re-certify head hydraulic relief and carrier auxiliary circuit calibration after rebuild.

Servicing the HH700 beyond the schedule

Predictive Maintenance & Fluid Analysis

The HH700 has no engine oil or coolant to sample, but its bar-and-chain oil supply and shared carrier hydraulic oil are worth tracking. Watch chain oil flow rate and clarity for early signs of pump wear or contamination, and include the carrier's hydraulic oil in its own sampling schedule since the head draws off that same reservoir. Track feed roller spike wear and delimb knife edge condition against hours, and log rotator play or noise trends rather than waiting for a hard failure.

Corrective & Common Repairs

Saw bar, chain, and nose sprocket/bearing damage is the most common repair on this head, especially after a stem binds the bar during felling. Feed roller spikes round off and lose grip on wet or frozen stems and need periodic renewal. Delimb knives dull faster in sandy, dirty, or frozen bark and tear rather than cut when worn, increasing feed roller slip. Hydraulic hoses at the rotator and saw box crack or chafe from continuous flex and are a routine replacement item, not a rare failure.

Overhaul & Rebuild Points

Because the rotator turns under load nearly every cut of the shift, its bearing and gear train see the highest duty cycle on the head and are the main overhaul point, along with seal renewal. Feed-roller-arm and delimb-knife pivot pins and bushings wear from continuous side load and need teardown inspection on a set interval rather than run-to-failure. Saw motor and drive components get rebuilt or replaced once beyond service limits. Mount hardware, whether yoke or bolted lower-link style, gets a full inspection at major rebuild.

Seasonal & Environment Servicing

Cold weather delays bar oil delivery for a minute or two after startup, so operators should warm the saw before hard cutting rather than loading it cold. Confirm the chain oil grade matches the season, since a summer-weight oil can gum up flow in freezing conditions. Frozen or sandy bark dulls delimb knives faster and rounds feed roller spikes sooner than clean, warm-season wood. Because the head shares the carrier's hydraulic system, winterizing the carrier's oil and filters also protects the head's own circuit.

HH700 attachments & work tools

Machine type / attachment framing

The HH700 is itself a single-grip harvester head (felling, delimbing, and bucking work tool), not a carrier machine. Its relevant compatibility profile is carrier fitment, rotator/mounting, saw, and processing components rather than tools mounted onto it.

Carrier compatibility

Factory installation documentation ties the HH700 to the Cat 320C hydraulic excavator, a medium (roughly 20-tonne class) carrier. The excavator must already have, or be retrofitted with, the matching auxiliary hydraulic control arrangement before the head can be installed.

Auxiliary hydraulic control kit

Fitting the head requires a dedicated auxiliary control arrangement on the carrier: mounting adapters, a wiring harness, and hydraulic hoses routed to a control box that runs head functions. The attachment relief valve on this circuit is factory set near 28000 kPa (4060 psi); exact setting can vary by carrier hydraulic/software revision, so confirm against the shop manual for the specific serial range.

Rotator and mounting

The head mounts to the carrier stick through a continuous hydraulic rotator on a yoke assembly. A later production change revised the rotator-to-yoke mounting to use tapped holes in the lower link for a bolted fit, a running design update rather than a selectable option.

Saw system

Processing uses an integrated bar-and-chain saw for felling and bucking. The saw bar retracts fully into the head body, and the head can be rotated to horizontal and raised clear of the ground for transport and saw servicing.

Feed and delimb system

Opposed feed roller arms grip and advance the stem, with roller clamp force set through a pressure-reducing valve; delimbing knives and a holding arm close around the stem to strip limbs during the feed stroke. Rollers open while knives and holding arm close, the standard single-grip harvester processing cycle.

Diameter/length measurement

Sibling Cat harvester heads in the same catalog family use one or two diameter sensors depending on size class for length and diameter measurement during processing. Whether the HH700 shares this exact sensor arrangement is not independently documented; confirm sensor count and calibration with the dealer for this specific head.

Service/safety configuration

Before hydraulic adjustment or service, the head's activation control lever is set to the LOCKED position per factory procedure. Saw and knife areas carry factory guarding consistent with standard felling-head practice; site-specific screens or extra guarding are dealer-fitted options, not a published factory menu.

Model family position

The HH700 is documented separately from Caterpillar's smaller harvester head lineup, with its own service literature and serial prefix. It represents a larger size class built around a medium hydraulic excavator carrier rather than the smaller dedicated forestry carriers associated with those heads.

All HH700 assemblies by section

Every catalogued assembly group for the Caterpillar HH700. Open an assembly to preview the parts inside — full OEM part numbers are available in Heavy Parts AI.

Service Equipment And Supplies
219-1627 Film Gp -Hh 700
13***39Film-Stripe; (Red)(625cm)0
21***61Film; (Hh)1
21***67Film; (700)1
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219-0048 Plate & Film Gp
13***76Film; (Warning) (Universal) (Lh Side Post Inside Cab)1
15***56Film-Instruction; (Control)1
16***91Film-Identification; (Chain Oil)1
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Work Tools
218-1927 Head Ar-Harvester
21***27Head Ar-Harvester1
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218-0495 Head Ar-Harvester
21***95Head Ar-Harvester1
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218-1928 Head Ar-Harvester
21***28Head Ar-Harvester1
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226-0888 Head Ar-Harvester
21***48Plate & Film Group1
22***86Attachment Ar1
22***88Head Ar-Harvester1
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219-0038 Head Ar-Harvester
21***38Head Ar-Harvester1
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218-0491 Head Ar-Harvester
21***91Head Ar-Harvester1
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218-0499 Head Ar-Harvester
21***99Head Ar-Harvester1
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218-0496 Head Ar-Harvester -(Hh700)(Harvester Head By Log Max)
21***96Head Ar-Harvester; -(Hh700)(Harvester Head By Log Max)1
21***98Head Ar-Harvester1
21***00Common Ar1
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226-0890 Installation Ar-Harvester Head
21***48Plate & Film Group1
22***90Installation Ar-Harvester Head1
22***92Installation Ar-Harvester Head1
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221-0102 Kit-Saw Repair -(Hh700)(Harvester Head By Log Max)
21***46Kit-Saw Repair; (Top Saw)1
22***79Kit-Hose1
22***80Kit-Repair1
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HH700 serial number reference

The PIN plate is a stamped metal tag located under a cover on the harvester-head frame, separate from the carrier excavator's own PIN plate. Read it as a 3-letter prefix (model-and-plant code) followed by a sequential unit number, e.g. CRA00001-UP - the letters identify the model family, the digits are production sequence, not a date code. If the tag is missing or worn, confirm the serial with your dealer using the head's parts record.

PrefixIdentifies
CRAHH700 single-grip harvester head - factory production prefix

Frequently asked questions

What carrier does the Cat HH700 mount on?

Factory installation documentation ties the HH700 to the Cat 320C hydraulic excavator, a roughly 20-tonne class carrier. The 320C needs a dedicated high-flow auxiliary hydraulic control arrangement fitted before the head can be installed and calibrated. Other carrier sizes may be advertised by dealers, but only the 320C pairing is confirmed in factory service literature.

What is the HH700's feed roller speed and hydraulic relief pressure?

The feed roller drive has a factory-tested maximum speed of about 151 RPM. The head's own hydraulic circuit relief is set to roughly 28000 kPa (4060 psi), while the host 320C carrier's auxiliary line relief is set separately at roughly 13100 kPa (1900 psi). Exact settings can vary by carrier hydraulic revision, so confirm against the shop manual for your serial range.

Is the HH700 the same as Caterpillar's smaller harvester heads?

No. The HH700 is a distinct, separate product line with its own serial prefix and service literature, not part of Caterpillar's smaller harvester head family. It is built for a larger, roughly 20-tonne class excavator carrier rather than the smaller dedicated forestry carriers associated with those heads, and its control setup is not documented as sharing that family's controller. Specs and service history for the two lines should not be mixed.

What HH700 owners discuss

How much wear should I expect on the bar and chain, and how does lubrication work?
Dedicated discussion of this exact head is scarce online, so this reflects general practice for hydraulic single-grip harvester saws of this size and era. The saw runs at full hydraulic power on every cut for a full shift, so bar rail and chain wear runs faster than on a handheld chainsaw. Owners check chain tension and bar oil flow daily and run a dedicated bar/chain oil rather than substituting generic hydraulic oil. In cold weather, oil delivery can lag a minute or two after startup, so operators warm the saw up before hard cutting. If a stem binds on the bar during felling, the drive can pull the chain into the nose hard enough to damage the nose bearing and sprocket — a known risk on any harvester saw of this style. Have your dealer verify saw drive and nose-bearing condition if a bind or chain-throw event has occurred.
What wear patterns show up on the feed-roller arms and delimb knives?
This is general single-grip harvester head experience rather than head-specific write-ups, since little dedicated discussion of this model exists online. Feed roller arm pivots and delimb knife pivots see heavy side load in continuous production cutting, and freeplay or elongated pins/bushings there typically shows up before the knives themselves are worn out. Knife edges dull faster in sandy, dirty, or frozen bark conditions; a dull knife tears bark instead of cutting it and increases feed roller slip rather than failing outright. Feed roller spikes round off with hours and lose grip on wet or frozen stems, so regreasing and periodic spike or tooth renewal is treated as routine upkeep, not a repair.
How durable is the rotator and mount, and does the mount style matter?
The continuous-rotation hydraulic rotator is one of the highest-duty-cycle parts on this type of head since it turns under load nearly the whole shift, so its bearing and gear train are inspected on a set interval rather than run to failure. Early-production units used a yoke-style hanger mount; a later production run moved to a bolted lower-link mount instead. That looks like a factory running change rather than a fix tied to a specific failure mode, and a used unit with the bolted mount is simply a later build. Either mount works fine when its pins and bushings are within spec — the practical question when buying is which style matches the carrier's linkage and which mounting hardware is still supported.
Do the hydraulic hoses and fittings wear out faster on this kind of head?
Yes, relative to a static excavator attachment. Because the head rotates continuously and flexes at the tilt joint on every cut, hose routing across the rotator and saw box sees more flex-and-twist cycling than most other work tools. Cracked outer cover, hardening, and hoses chafing through against a bracket are the typical failure modes, and running overheated or wrong-viscosity oil accelerates it. Shop practice for this class of head is to check hose routing and fittings at the rotator and saw box every shift rather than waiting for a line to fail with the head extended. Have your dealer verify hose condition and routing at the rotator if any weeping or chafing is visible before returning the head to production.
What carrier and hydraulic setup does this head need to work properly?
This head has no engine or tank of its own and draws all power from the carrier, so it has to be matched on auxiliary flow and pressure, not just lift capacity. The documented factory pairing is a roughly 20-tonne class excavator carrier fitted with a high-flow auxiliary circuit and control valving dedicated to the saw, feed roller, and rotator functions. Too little auxiliary flow shows up as slow feed speed and a saw that bogs under load; a mismatched high-pressure circuit not calibrated for the head risks overdriving the saw motor or rotator. Because the auxiliary control arrangement has to be installed and calibrated to the specific carrier, pairing a used head with a different excavator is a job for a dealer or qualified hydraulics shop, not a straight hose swap.
What should I inspect before buying a used one of these heads?
Check the saw bar rails and nose sprocket/bearing first — that is the highest-wear, highest-cost item to find damaged, especially any sign of past bar pinching. Check feed roller arm pivots and delimb knife pivots for freeplay, and knife edges and feed roller spikes for wear. Cycle the rotator through full rotation and feel for stiffness, noise, or excess backlash, and confirm whether the unit has the original yoke hanger or the later bolted lower-link mount so it matches what the intended carrier's linkage expects. Inspect all hoses and fittings around the rotator and saw box for cracking, chafing, or field repairs. Ask for maintenance and lubrication records rather than relying on hour meter alone, since duty cycle affects wear more than raw hours. Have your dealer verify hydraulic flow and pressure calibration against the carrier you intend to run before putting the head into production.

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

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