Excavator Automatic Grease System: Typical Configuration & BOM (Application Note)

An automatic grease system on an excavator is not a single product but a small engineered network: pump, progressive distributor blocks, tubing, fittings, and a controller, all sized to the machine’s point count and duty cycle. This application note documents a representative configuration for a 20-ton class crawler excavator, covering the working attachment (boom, arm, bucket pins and cylinder mounts), the swing bearing, and accessible undercarriage points. It complements our broader excavator lubrication system selection guide, which compares system types; here we focus on how one concrete build is put together, adjusted, and maintained.

System Overview: What the Autolube Has to Cover

A 20-ton excavator typically has 14-22 primary structural grease points (boom foot, boom/arm/bucket pins, cylinder mounts, swing bearing) plus 6-12 or more secondary points when the design also serves linkages, coupler pivots, and undercarriage items. Once you group the fittings that sit in awkward or guarded positions — the reason most fleets automate in the first place — a realistic full-coverage design lands in the 35-40 point range. Industry references align with this: a mainstream 20-ton excavator is documented with around 20 manual lubrication points, and full-coverage autolube kits for this class are commonly quoted at 30-50 points.

All of these points share one requirement profile: low volume per event, but high pressure. Each pin needs only a fraction of a milliliter per shot, yet the system must push NLGI 1-2 EP grease through long small-bore lines against contamination and back-pressure. That combination is what a progressive system is built for, and why progressive — not parallel injector — architecture is the default on mobile equipment. A progressive circuit also gives built-in monitoring: if any single outlet or line blocks, the entire block stalls, which a cycle indicator or pressure switch flags immediately.

Mapping the Lubrication Points into Circuits

Before sizing hardware, group the points into logical circuits by location and grease demand. A proven grouping for this machine class:

• Upper structure direct points (~10): swing bearing raceway (2-4 injection points), swing pinion feed, boom foot left/right, boom cylinder mounts. These sit close to the pump and master block and are served directly from master block outlets.
• Boom and arm circuit (~16): boom cylinder rod end, arm cylinder both ends, arm pivot, and the arm-side linkage pins — clustered along the attachment and ideal for one secondary block mounted on the boom.
• Bucket and front linkage circuit (~12): bucket pins, link pins, coupler pivots, plus any routed lower-frame points, served by a second secondary block near the arm tip.

Grouping this way keeps individual point lines short (1.2-3.5 m from the block outlet is good practice), concentrates the longest runs in the two main lines that cross the boom foot and swing center, and makes troubleshooting intuitive: a stalled secondary block points to one zone, not the whole machine.

Pump and Controller Selection

The pump is sized on three criteria: voltage available on the machine, discharge volume against total point demand, and reservoir capacity against refill interval. For this configuration the reference unit is a compact DC piston pump of the DC24V-B class with the following working envelope:

• Power: 24V DC machine supply (12V DC optional), 50W motor, ~3A loaded current
• Max pressure: 25 MPa (250 bar) — enough to overcome long-line and cold-grease resistance
• Discharge: 5.5 ml/min per outlet, 1-3 independent outlets
• Reservoir: 2L transparent tank with optional low-level switch
• Grease range: NLGI 000# to 2#; protection IP65; operating temperature -30°C to +80°C
• Integrated timer: pause adjustable 4 minutes to 15 hours, run time adjustable 8 seconds to 37.5 minutes

Two outlets are used in this build: one dedicated to the attachment cascade, one serving the upper-structure master block outlets. At the consumption rate calculated in the commissioning section below, the 2L reservoir gives roughly a one-week refill interval at 10 operating hours per day. For cold climates, specify NLGI 000-0 winter grease within the pump’s rated range rather than derating the hardware.

Sizing the Progressive Block Cascade

The distribution network uses progressive distributor blocks from the DJF2000 series: carbon steel sections, 25 MPa maximum / 1.4 MPa minimum working pressure, and per-outlet discharge from 0.16 to 1.12 ml per cycle depending on the section model. Sections are modular (3-10 per block, 1 or 2 outlets each), and discharge sections can be mixed within one block — the key to matching dosage per point. Full section-level data is on the DJF2000 block specification page.

A representative sizing for 38 points:

• Master block (upper structure): 6 sections, 12 outlets. Nine outlets feed the upper-structure direct points, with larger-discharge 35-series sections (0.56 ml per outlet) on the swing bearing raceway; three outlets feed downstream secondary blocks.
• Secondary block A (boom/arm, 8 sections, 16 outlets): 20-series sections at 0.32 ml per outlet — the standard dose for medium pins and bushings.
• Secondary block B (bucket/linkage, 6 sections, 12 outlets): mixed 20/25-series sections (0.32/0.40 ml) to give the high-wear bucket pins a larger shot.

Two cascade rules matter. First, the master outlet feeding a secondary block should ideally deliver at least the secondary block’s total per-cycle volume; if it delivers less, the secondary simply completes its cycle across several master cycles, which is acceptable but slows dosing to that zone. Second, never cap a progressive outlet — combine unused twin outlets or bridge sections instead, because a dead-ended outlet stalls the entire block.

Typical BOM for a 20-Ton Excavator

The bill of materials below reflects the configuration above. Quantities assume 38 active points and average routing distances on a 20-ton crawler machine; adjust tubing length to the actual machine.

For interactive sizing of pump and block combinations against your point count, the lubrication system selector is a fast starting point before detailed layout.

Tubing Routing and Installation Practice

Routing is where mobile-equipment installs succeed or fail. Working guidelines for this configuration:

• Main lines (Φ8): keep pump-to-master and master-to-secondary runs in the 1.5-4.5 m envelope where possible, following the machine’s existing hose paths. At the boom foot and swing center, route through the same articulation loops as the hydraulic hoses, leaving slack for full range of motion without kinking.
• Point lines (Φ6): 1.2-3.5 m typical per outlet. Clamp every 300-500 mm, and sleeve any line that crosses a wear edge with spiral guard.
• Pump mounting: inside the upper-structure compartment, vertical, on a rigid rubber-isolated bracket; the IP65 enclosure tolerates wash-down and dust, but direct impact zones should be avoided. Keep the fill point reachable at service-platform level.
• Block mounting: master block beside the pump; secondary blocks on the boom/arm in positions shielded from material contact, all on rubber-isolated brackets to survive vibration.
• Electrical: pump power tapped from a keyed 24V circuit so the system only runs with the machine on, with an inline fuse near the battery and the reservoir low-level alarm wired to the cab if fitted.

Commissioning: Cycle Time and Discharge Settings

Commissioning has three steps. First, pre-fill: fill the reservoir with clean grease, run the pump with the master inlet line loose until bubble-free grease appears, then tighten and repeat at each secondary block inlet. Progressive blocks must never start dry against long empty lines, or the first real cycles are spent compressing air.

Second, set run time: measure how long the pump needs to complete one full master block cycle (watch the cycle indicator pin travel through its full stroke sequence). Set run time to that measured value plus roughly 20% margin — typically a few minutes at 5.5 ml/min per outlet. Each master outlet then delivers its rated shot (0.32-0.56 ml in this build) once per cycle.

Third, set pause time: size it from consumption. At 38 points averaging ~0.35 ml per shot, one full system cycle moves roughly 13-15 ml. A 30-minute pause at 10 operating hours per day gives 20 cycles and about 260-300 ml/day — equivalent to or slightly above manual greasing practice, which is the right starting point for dusty work. At that rate the 2L reservoir lasts about 6-7 operating days. Reduce the pause (or fit larger-discharge sections on problem pins) if joints purge dry; extend it if grease visibly piles up at seals.

Field Maintenance Notes That Keep the System Honest

A progressive autolube is close to fit-and-forget, but four habits keep it reliable over years of service:

• Watch the cycle indicator weekly. A stalled pin means a blockage downstream — find it by cracking outlet fittings progressively from the master block outward. Stall-to-fault isolation is the system’s core diagnostic advantage.
• Refill with clean grease only. Most progressive block failures trace back to contaminated grease introduced at refill, not to the blocks themselves. Use a filler pump with a sealed coupling and wipe the fill port first.
• Inspect articulation loops monthly. The boom foot and swing center crossings are the only places tubing genuinely wears; re-sleeve or re-clamp at the first sign of chafing.
• Seasonally re-check dosage. If ambient temperatures drop well below freezing, switch to the NLGI 000-0 grade within the pump and block ratings rather than forcing summer grease through winter lines.

Configured this way, the system covers every structural point on the machine from one reservoir, doses each joint in proportion to its wear rate, and tells the operator the moment any single point stops receiving grease. For application support on a specific machine or fleet mix, our excavator lubrication solutions page outlines system options across machine classes.