Grease Gun Care & Maintenance

To view the Arlube range of grease guns and lubrication equipment that Josco offers, please click here. This content regarding grease gun care and maintenance applies to all brands of grease guns. If any of your grease gun care questions aren’t answered in this article, please submit an enquiry form to speak to one of our friendly customer service team members.

Issue: The grease gun won’t pump grease.

The most common cause is an air lock. This can be fixed by continuously pumping to see if the air will pump out. Secondly by unscrewing the barrel one turn and continuously pumping, then tightening the barrel when the grease pumps. If these methods are not successful, use a clean rag on your fingers and push the grease up inside the cartridge from the plunger end so there is a small dome of grease on the opposite end of the cartridge. Install the cartridge with the dome of grease filling the space under the grease gun head and eliminating air locks. All types of grease guns can have air locks – manual, electric, air and mini grease guns.


Issue: When pumping grease, there is no pressure and the grease is coming out around the coupler.

This is a common occurrence when a coupler fails. A coupler is designed to fit over a standard sized grease nipple. Unfortunately, the are many oversized grease nipples and the coupler can be stretched past its elasticity to fit an oversize grease nipple. After this it will no longer hug the nipple enough to create the seal needed to push the grease into the nipple and the result is grease squeezes out the edges of the coupler. This gives the perception that the gun is faulty whereas it may be a damaged coupler at fault. Remove and replace the coupler. (ArLube grease nipples are the correct size and hardened for long life).


Issue: The grease gun plunger is too big for the cartridge and won’t go in.

This is a common misconception in a new grease gun. This is caused by the plunger being new and stiff. To remedy, pull the plunger back and before putting the cartridge in, smear some grease around the inside of the barrel, as far as you can reach. Slide the plunger up and down several times for the plunger to pick up the grease and lubricate itself. This will help the plunger enter the cartridge easily.
After doing the above, the main reason a plunger still won’t enter the cartridge is it has an air lock and because it is pumping air, the plunger will not move forward after compressing the air into the air lock.


Issue: Grease won’t pump through the needle point coupler.

Many of the cheaper needle point couplers are not case hardened so if they are dropped and the point is damaged, grease won’t pump through. Arlube have a case hardened needle point which tends to avoid this problem.


Issue: The flexible hose appears to sag and bend over a period of time.

This is due to the hose being continually fully primed with grease and the weight of the hose causes a bend at the grease gun end. Arlube grease guns have a flexibe hose with a spiral wire protector at the gun end to help take the load and stops the hose developing a bend. There are 4 lengths available in 200mm, 300mm, 450mm and 700mm.


Issue: Grease Contamination

Over a period of time, couplers and flexible extensions may collect dirt. There is a risk the dust and grit contamination can then be transferred to whatever you are greasing. Replacing your coupler and flexible extension periodically helps prevent this problem and is always good practice.


Issue: It appears the grease gun won’t pump and is locked over the nipple.

This could be a blocked nipple and is particularly a problem with battery powered grease guns. People tend to keep their finger on the trigger and run the battery power down quickly, not solving the problem. Replace the blocked grease nipple. To release a grease coupler from a nipple, tip it to the side of the nipple.


Issue: While under pressure, the barrel comes away from the head of the grease gun.

This is often due to cross-threading. If your grease gun has a fine thread on the barrel and head, care needs to be taken when screwing the barrel into the head. To avoid cross-threading, always ensure the barrel is square to the head before screwing the barrel into the head. If there is a lot of grease in the head, this also can lead to cross-threading the barrel.