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How to use an air grease gun

Updated: 21.10.2026

The first pull on a new cartridge often does nothing, and the usual cause is air in the barrel rather than a dead gun. This is how to use an air grease gun so grease arrives as a solid slug and you stop when fresh grease shows. The Draper 70836 listing does not print Kennedy’s sequence, so the sheet in your box still wins if it differs. The [air grease gun comparison](/hub/compressors/air-grease-gun) is the product page, not the procedure. Products Compared used maker manuals and HSE bulletins. We did not run a lab test. A qualifying purchase through an amazon.co.uk link can earn us a commission at no extra cost to you.

The first pull on a new cartridge often does nothing, and the usual cause is air in the barrel rather than a dead gun.

Our top picks

Draper Draper 70836 air grease gun (400 cc)

Best overall

Draper Draper 70836 air grease gun (400 cc)
7.4/10about £30.99
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KATSU KATSU 40 litre pneumatic grease pump

Rank 2

KATSU KATSU 40 litre pneumatic grease pump
6.4/10about £119.99
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KATSU KATSU 12 litre pneumatic grease pump

Alternative

KATSU KATSU 12 litre pneumatic grease pump
6.2/10about £87.99
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On this page
  1. 1.Before you connect air
  2. 2.Load a cartridge or a bulk fill
  3. 3.Bleed until the grease is solid
  4. 4.On the nipple, then off
  5. 5.When to stop and get help

Before you connect air

Set the regulator to the window on the plate, not to the tank gauge. Kennedy recommends about 90 psi for the PGC400. Draper’s page for the 70836 prints 30–120 psi. Sealey’s SA40 notes ask for dry air and a few drops of SAE 30 in the inlet if the maker asks for it. Put on eye protection before the hose is live. Disconnect the air before you service the gun, do not point the nozzle at anyone, and do not pull the trigger until the nozzle is on the nipple. A long airline is a compressor question, on the air compressor page. Air stays off with the barrel open.

Load a cartridge or a bulk fill

Kennedy’s cartridge order is the pattern unless your sheet says otherwise. Unscrew the head, latch the rod back, insert the cartridge, then release the rod so the follower sits on the grease. For a bulk fill, load from a tub or a filler pump and bring the follower down with the air expelled. The Draper bullets list bulk loading and a 400 cc body, not a keg. The KATSU 12, 20 and 40 litre pumps are follower-plate machines. You do not push a 400 g cartridge into them. Use that maker’s fill picture, or the plate sits crooked and the pump sucks air.
Draper Draper 70836 air grease gun (400 cc)

Testsieger

Draper Draper 70836 air grease gun (400 cc)
7.4/10about £30.99
View offer

Bleed until the grease is solid

Kennedy’s bleed is to loosen the head one or two turns and work the plunger until grease, not froth, appears at the threads, then tighten. Some guns, including the Laser Tools 0241 pattern, bleed at a plug. The Draper listing names air bleed valves without saying which you have. Use the one on your gun. Finished means a continuous slug at the coupler before you go near a nipple. If nothing comes out, clean a blocked jaw and bleed again before you condemn the trigger.

On the nipple, then off

Push the coupler on square so the jaws snap behind the nipple. Pull the trigger only while the jaws are home: one pulse on a one-shot gun, a short hold on a continuous gun. Do not hold the hose as a grip under pressure. To come off, tilt the coupler, about the 45-degree swing Laser Tools describes, and pull as it breaks the seat. A straight yank unscrews or snaps the nipple. If a nipple comes off under pressure, do not refit it. HSE’s track-tensioning bulletin records a fatality after a nipple detached from a hand gun. Wipe the jaws before the next nipple.

When to stop and get help

Stop when fresh grease appears at the seal, when the coupler will not sit square, or when the gun spits air again. A pinpoint mark, numbness, or grease under the skin is an emergency. HSE notes serious injection cases above 100 bar, anecdotal harm from about 7 bar, and hand guns tested above 600 bar. The British Orthopaedic Association calls this time-critical. You get to hospital and say it was grease from a pressure gun. This page does not describe treatment. At work, get a competent person if nobody has been shown how to isolate the airline. The receiver, not the grease hose, falls under the Pressure Systems Safety Regulations 2000 above 0.5 bar. If a lever would have been calmer, that comparison is on the air versus manual page.

Common questions

How do you load a 400 g cartridge?
You isolate the air, unscrew the head, latch the rod back, drop the cartridge in open end towards the head, and let the follower down onto the grease. Then you bleed until a solid slug appears. That is the Kennedy pattern. The Draper listing confirms a 400 cc body and a plunger rod. It does not replace the sheet packed with your gun.
Why does nothing come out after a refill?
Trapped air is the usual reason. A dried coupler or a seal left inside the barrel does the same thing. Loosen the head or open the bleed, work the plunger until grease is solid, and tighten again. Do not keep the airline wide open and hope the air pocket will clear itself through a nipple.
How do you bleed trapped air?
On the Kennedy pistol you loosen the head one or two turns and work the plunger until grease shows at the threads. On guns with a bleed plug you open that plug instead. The Draper bullets name air bleed valves without a drawing. Finished means continuous grease at the coupler, not a hiss followed by a sputter.
How does a four-jaw coupler go on and come off?
You push it on square until the jaws click behind the nipple. You release it by tilting, around 45 degrees in the Laser Tools note, while you pull. You do not yank straight back along the nipple. Grease the jaws if the manual says so, and do not pull the trigger until the coupler is seated.
How much grease does one bearing need?
Kennedy’s manual talks about two or three trigger pulls for an average bearing, as a rule of thumb. The real stop is fresh grease at the seal. A continuous-flow gun will pass that point quickly if you hold the trigger. Extra grease on the outside of the joint is waste. Extra grease forced into a sealed boot is damage.

Related pages

Air grease gun buying guide

Air grease gun

Best air grease gun for a UK home workshop or a keg

Air compressor for a grease gun: CFM, psi and tank

Air grease gun vs manual: when the airline is worth it

Sources

Public UK sources and maker pages from the research digest, checked for this page on 20 October 2026. Listing prices, stars and review counts are amazon.co.uk figures from the comparison files.

  1. HSE: hydraulic injection injury (retrieved 20 October 2026)
  2. HSE: track tensioning and high-pressure injection (retrieved 20 October 2026)
  3. HSE: PUWER overview (retrieved 20 October 2026)
  4. HSE: Pressure Systems Safety Regulations (PSSR) (retrieved 20 October 2026)
  5. Draper Tools: air grease gun 70836, 400 cc (retrieved 20 October 2026)
  6. Kennedy PGC400 instructions (Cromwell) (retrieved 20 October 2026)
  7. Sealey SA40.V2 instructions (retrieved 20 October 2026)
  8. SGS Engineering: air compressor buyer's guide (retrieved 20 October 2026)