DOOST D-series lock on grease coupler

The D-series grease-coupler from DOOST Engineering offers you a faster cleaner and less wasteful method of greasing all SAE and metric Zerk fittings quickly and hassle free. With our 360 degree quick-release thumb lever, and heavy duty hydraulic sealing system, this is your solution to long-term greasing operations big or small. With its innovative locking mouthpiece, leak-free greasing under pressure is no match for the D series and single-handed release of more than 10.000 PSI is achievable. No empty promises only our guarantee that this is the greasing tool for you.

Easy handling
high quality construction

  • Single handed quick release up to 10 000 PSI
  • High tensile anodized steel construction
  • Innovative locking mouthpiece
  • Leak free greasing
  • M10 and 1/8 NPT compatible
  • Works with all standard grease guns
  • Safety locking mechanism

Made in Germany -
Greasing the World

  • 1 year manufacturers warranty
  • Saves you time and money
  • Fully serviceable
  • Spares kits available
  • Fast and efficient greasing
  • Great backup and customer service
  • Constant research and development

Push it!

Single-handed release
of up to 10.000 PSI safely

Many promise, we guarantee! Fits all SAE and Metric Zerk specification grease nipples.


Lock on safely!

Leak-free greasing
with our innovative mouthpiece

Once secured to the fill nipple, pressure has been applied and the seal has been made, the coupler will not release itself until you apply downward pressure on the 360-degree thumb lever. This enables you to fully use two hands on your grease gun. No holding of the coupler required during greasing.


Leak-free greasing!

Works on all
standard reputable grease guns

The D-series is available in M10x1 and 1/8 NPT threads. Works on all hand operated and pneumatic grease guns from reputable manufacturers such as Lincoln, PowerLuber, Dewalt, Lumax, Alemite, Edelmann, Grainger, SKF, Macnaught, ADT, Milwaukee, John Deere, Wilmar, Legacy, Allstar, Sealey, Draper, UMETA.

2 Versions

thumb lever

The D-series locking system is activated by a 360° thumb lever. The downward push of the lever retracts the sleeve thus exposing the mouthpiece cylinder. Place over the fitting, push and release the thumb lever. The jaws automatically lock on thus creating the start of a perfect seal.


Saving you time and money
putting you first

The DOOST grease couplers are easily serviceable and can be dismantled in a matter of seconds. Replacing seals that have worn over time is quick and easy and wont create downtime on your greasing jobs. We offer replacement kits for all moving parts and seals.


Grease smarter!

Precision engineering
Save and secure working

We recommend the use of Personal Protection Equipment in all greasing applications, after all safety is the most important factor in any working environment.