S-704S Lever Action Grease Gun

Frequently Asked Questions: Lever Action Grease Gun 10 oz.

What features matter most in a lever grease gun?

Four features separate professional lever guns from commodity guns: pressure rating, head construction, cartridge compatibility and capacity. On the S-704S: 6,000 PSI (413 bar) working pressure for standard service, drop-resistant forged steel head for impact tolerance, 10 oz. / 300 cc capacity designed for compact workshop and light-fleet use, and 4-way loading (cartridge, bulk, suction, filler pump). The compact 300 cc reservoir suits single-machine service and mobile technician vans where full-size 500 cc guns are oversized for the workload. Steel head construction is the key differentiator from aluminium-head alternatives. Steel absorbs drops onto concrete and steel workbenches without cracking.

What PSI does a lever action grease gun produce?

The S-704S develops 6,000 PSI (413 bar) at the coupler output . Standard-duty pressure suitable for automotive, light-agricultural and workshop service. 6,000 PSI handles 90 percent of typical service fittings without issues. For crusted or contaminated fittings on heavy equipment left outdoors, step up to 10,000+ PSI guns like the S-707 or S-724DC. The S-704S's 40:1 pressure ratio (industry premium tier for lever guns) multiplies 150 PSI of operator input force into 6,000 PSI at the coupler. Pressure ratio is a fixed mechanical property and does not vary with operator technique.

How much grease does a lever action gun deliver per stroke?

The S-704S delivers 1 gram per stroke, or 1 ounce per 28 full-lever strokes. A full 10 oz. (300 g) fill delivers 300 strokes before needing reload. For service planning: a 20-gram fitting shot needs 20 lever strokes, a 12-fitting light-vehicle service needs 240 strokes, a 10 oz. fill covers one full vehicle with margin. Stroke-count planning works precisely because output is constant across the full reservoir. The first stroke after reload and the last stroke before empty both deliver 1 gram at full 6,000 PSI. The 10 oz. compact capacity is right-sized for service-van use where space matters more than reload frequency.

How to load a cartridge in a lever action grease gun?

Load a cartridge in six steps. Retract the plunger rod fully and lock it into the side slot. Next, unscrew the barrel from the head. Then, peel the metal pull-tab off the cartridge nose end. After that, insert the cartridge nose-first into the 300 cc barrel. From there, peel the plastic seal off the bottom and screw the head back onto the barrel. Finally, release the plunger rod from the side-slot lock so the follower spring seats the cartridge. The S-704S's 300 cc reservoir accepts the standard worldwide 14 oz. (400 g) cartridge . The cartridge is cut short to fit the compact barrel, or a smaller-capacity cartridge variant is used if available locally. For full bulk fill, follow the bulk-load procedure instead.

How to bulk fill a lever action grease gun step by step?

Bulk-fill the S-704S in seven steps. (1) Retract the plunger rod fully and lock it into the side slot on the barrel. Next, Unscrew the barrel from the head. Then, Dip the barrel mouth into a 5 kg, 15 kg or 18 kg grease pail. After that, Pack grease firmly into the 300 cc reservoir using a scoop or spatula, working against the barrel sidewalls to avoid air voids. From there, Screw the barrel back onto the head. Finally, Release the plunger rod from the side-slot lock so the follower spring compresses the grease column. And last, Crack the head a quarter turn, pump 3-5 strokes to purge air, retighten once grease flows without bubbles at the head seam.

How to prime a lever action grease gun after loading?

Prime the S-704S in four steps after every reload. Ensure the head is screwed snug against the barrel. Next, crack the head a quarter turn to open the bleed path. Then, with the coupler disconnected, pump the lever through 3-5 full strokes to purge air from the 300 cc reservoir. After that, retighten the head once grease flows from the head seam without bubbles. The compact 300 cc reservoir primes faster than full-size 500 cc guns because less air volume needs purging. Never prime against a connected fitting. Air must escape at the head, not into a bearing. If priming takes more than 5-6 strokes, check for incomplete bulk packing or a worn plunger seal.

How to bleed air from a lever action grease gun?

Bleed air from the S-704S in five steps. Retract the plunger rod fully and lock it into the side slot. Next, crack the head a quarter turn to open the bleed path. Then, release the plunger rod so the follower spring compresses the grease column against the head. After that, pump the lever through 3-5 full strokes while holding the gun with the head tilted slightly upward. Finally, retighten the head once grease flows from the head seam without bubbles. The tilt helps trapped air rise to the head where it can escape through the bleed gap. Never try to bleed air while the coupler is connected to a fitting. Air will escape into the bearing and potentially damage seals.

How do I fix an air lock in my lever action grease gun?

Air lock on the S-704S is fixed in six steps. Disconnect the coupler from any fitting. Next, retract the plunger rod fully and lock it into the side slot. Then, crack the head a quarter turn to open the bleed path. After that, release the plunger rod so the follower spring compresses the grease column. From there, pump the lever through 3-5 full strokes until grease flows from the head seam without bubbles. Finally, retighten the head. If air lock repeats, inspect for incomplete bulk-fill packing or a worn plunger seal. The 300 cc compact reservoir traps less air than larger guns during bulk fill, but aggressive packing leaves voids even in compact reservoirs. Use a scoop or spatula and work grease against the sidewalls to minimize void formation during packing.

Can I use a grease gun on ball joints and tie rod ends?

Yes. Ball joints, tie rod ends and similar sealed automotive chassis components are primary S-704S applications. The 6,000 PSI output is adequate to seat grease into these fittings without overpressure risk to the component seals. Lubrication approach: use the flex hose for angled access to ball joints hidden in suspension geometry. Use the rigid steel extension for straight access. Never over-pump. Watch for grease emergence at the boot seal and stop when the boot expands slightly. For stiff boot seals that don't show grease flow, the fitting may be blocked and need professional service rather than additional pumping. A 20-gram shot per fitting is typical for ball joints. Tie rod ends take less at 10-15 grams per shot.

Can I use a grease gun on a lawn mower?

Yes, lawn mower decks, wheel bearings, spindle bearings and linkage fittings all accept standard zerk grease connection, matching the S-704S's hydraulic coupler. For riding mowers with 6-10 grease points, the 300 cc capacity covers multiple machines per fill. For commercial zero-turn mowers with more fittings (15-20 points), one fill covers one full machine. Mower grease selection: NLGI #2 lithium complex for general service, moly-fortified EP for deck spindles under shock loading, calcium sulphonate for coastal or wet-climate use. Never grease sealed (non-zerk) bearings. The 6,000 PSI of the S-704S can blow sealed bearing seals if accidentally forced against them.

What is the difference between lithium and calcium based grease?

No. Mixing grease chemistries causes thickener separation and can damage downstream bearings. Lithium complex, calcium sulphonate, aluminium complex and polyurea thickeners all use different chemistry and form slurry when combined. To change grease types in the S-704S: empty the 300 cc reservoir completely, unscrew the head, wipe the compact barrel interior with solvent-dampened lint-free rag, solvent-clean the head internals and non-return valve, reassemble with the new grease and prime per the procedure. For workshops running multiple grease types on different equipment, dedicate one S-704S per grease chemistry and label each gun with chemistry and NLGI grade on visible tape.

How to flush a grease gun when switching grease types?

Flush the S-704S in seven steps when switching grease chemistries. (1) Depressurize the gun by retracting the plunger rod and pressing the bleeder valve. Next, Pump the gun empty through the coupler into a waste container. Then, Unscrew the head and bottom cap (if accessible). After that, Wipe the 300 cc barrel interior with solvent-dampened lint-free rag until no residue appears. From there, Solvent-clean the head internals, non-return valve and coupler. Finally, Inspect the plunger seal for circumferential wear. Replace from the STAR spare kit if worn. And last, Reassemble with the new grease chemistry and prime per the procedure. Never use WD-40 as a flush solvent. It leaves residue that contaminates fresh grease. Use dedicated grease-gun solvent or mineral spirits.

Should I store my grease gun nozzle-down?

Store the S-704S horizontally with the plunger rod disengaged for any period over a week with grease loaded. Oil bleed (base oil separating from grease thickener) happens even in compact 300 cc reservoirs and is driven faster by vertical storage. Horizontal storage minimizes gravity-driven oil settling. Releasing the plunger rod from the side-slot lock lets the follower spring keep the grease column compressed against the head. For storage over 30 days: drain the reservoir completely, wipe the barrel interior with solvent, reassemble with the plunger seal lightly greased, store dry at 10-30°C away from direct sun. Never store nozzle-down. Grease settles at the head and can harden against the non-return valve.

What PPE should I wear when using a grease gun?

Mandatory PPE at 6,000 PSI: wraparound safety glasses, nitrile chemical-resistant gloves, closed-toe work boots and long-sleeve protective clothing. Safety rules: never point the coupler or flex hose at any body part, keep the lever-hand behind the coupler head, inspect the flex hose before each use for cracks or bulges, never test grease flow by pressing the coupler against skin or fabric. The S-704S at 6,000 PSI operates below the 7,000 PSI threshold above which amputation risk from grease injection injury rises sharply, but injection injury even at 6,000 PSI remains a surgical emergency. Any suspected injection injury requires immediate hospital treatment regardless of initial wound appearance.

How to prevent grease from hardening inside the gun?

For regular workshop use (2-5 reloads per shift), clean the S-704S every 6 months. For service-van mobile use with daily reloads, every 3 months because dust and humidity cycling accelerate contamination. Cleaning procedure: depressurize by retracting the plunger rod and pressing the bleeder valve, empty the reservoir through the coupler into a waste container, unscrew the head, wipe the 300 cc barrel interior with solvent-dampened lint-free rag, solvent-clean the head internals and non-return valve, inspect the plunger rod seal for circumferential wear, reassemble with fresh grease lightly applied to seals. The compact 300 cc reservoir cleans faster than full-size guns because less grease needs emptying and the shorter barrel is easier to reach through.

Which is better: lever action or pistol grip grease gun?

For multi-fitting service rounds and high-pressure applications, lever action like the S-704S is better. For tight-clearance and one-handed access, pistol grip is better. Lever action develops 6,000 PSI versus typical pistol-grip output of 4,000-5,000 PSI, and delivers more grease per stroke through the longer lever arm. Two-handed operation is required on lever guns. For service routes covering 15-25 fittings per machine, the S-704S is the production tool. For occasional one-off lubrication in tight spots where a long lever doesn't fit, pistol grip supplements the lever gun. Most professional shops own both and match tool to job. The S-704S at 300 cc compact size minimizes the lever-gun handling disadvantage in tight spaces.