Remove the HLG pump assembly from the CALM cabinet.
Remove the HLG reservoir, clean the grease out and wash it with the degreaser.
Remove the pressure gauge .
Remove the 1/4" fittings . NOTE: The amount of fittings will depend on the machine model and configuration.
Remove the pressure sensor 
Remove all of the NPT plugs  from the manifold.
There are two check valves within the HLG pump manifold.
The main check valve  located on the bottom of the HLG manifold and prevents the pressurized grease to flow from the pressurized lines back into the HLG reservoir. remove the spring and the ball. Inspect the o-ring inside the check valve cavity, replace with 57-22201 if necessary.
The bleed back circuit check valve located on the top of the HLG manifold and shuts off the bled back circuit when the HLG canister is under pressure. Besides the spring and the ball  there is a snubber setscrew  under the check valve ball. Remove the snubber setscrew when cleaning the manifold passages.
Clean the HLG manifold ports out with degreaser and compressed air.
Reassemble the HLG manifold in the reverse order. IMPORTANT: Torque the snubber setscrew  to 2 in-lbs (0.226 Nm).
Install the HLG pump into the CALM cabinet and reconnect the grease lines.
Verify that the pickup tube has an updated 80 mesh filter screen. Replace if nesessary. Refer to the Haas Liquid Grease Filter Kit for more information.
Fill the HLG reservoir with compatible lubricant to 1/2" (13 mm) below the threads on the reservoir. Refer to the Lubricant, Grease, and Sealant Tables for Haas Machine Components.
Prime the lube lines as described in the Minimum Lubrication - Axis - Grease Reservoir - Haas Liquid Grease - Refill instruction.