In step 8, it will be necessary to pull the vacuum on the reservoir to empty it. This will compress the spring on the reservoir. The spring should only be compressed to 0.45". A gap tool should be used to prevent the spring from being over-compressed. 

The image to the left is the blueprint for the tool used in the Haas factory for this purpose. However, anything that is 0.45" will be suitable.

A threaded hole on the side [1] can be drilled, and a bolt screwed in to make it easier to use. 

Run the first line of the program to release the brake.

N01 M11 //Disengage Brake.

After the brake has been disengaged, remove the airline from the unit and unscrew the front enclosure. 

Check if the clear hose on the booster reservoir [1]. If it has any bulges, drips, wetness, or is not connected. If any of those apply, contact Haas service for instructions. Check the booster reservoir spring. It should be somewhere in the middle, neither fully extended or fully contracted. [2] 

The item labeled [3] is the vacuum barb on the booster reservoir.

Attach the vacuum hand pump to the barb fitting on the booster reservoir. [1] 

Remove the top enclosure cover and remove the brake fluid plug. Next, attach the bleeding tool to the fluid port.

Be sure to grab the tool at the cross point. It only needs to be hand tight. 

Make sure the tool is in a closed position by pulling the level perpendicular to the tool [1]. 

Remove the rear enclosure of the rotary unit to expose a yellow cap covering the large air cylinder, which is needed to bleed the unit. Attach the female Schrader fill valve to the male Schrader valve.

Attach a hose to the Schrader valve as shown and run the hose into the reservoir of the upper bleed tool. 

Loosen the Schrader valve all the way. This will close off the circuit. 

Open the tooling valve.

Note: Valve handle should be aligned with the tool [1]. 

Using the hand pump, pull vacuum on the hand pump until it is clear that the spring on the booster reservoir has been fully compressed. 

Close the upper ball valve to the tool and tighten the Schrader filler valve. This will open back up the circuit. 

Release the vacuum on the hand pump. Change the dial to the hand pump [2]  to apply pressure to the circuit. This will extended the spring on the booster reservoir. 

Note: Fluid should now be flowing from the reservoir through the Schrader filler valve and back into the upper tooling reservoir. 

Repeat this step 5 to 8 times or until it is clear that there are no longer any bubbles in the system. 

Once it is clear that there are no longer any bubbles, open the tooling valve [1] and loosen the T - Handle on the Schrader filler valve. 

Place the gap tool of 0.45" up against the brake booster, ensuring gap tool is flat against surface [1]. 

Pull vacuum on the hand pump until the booster spring is compressed against the gap tool. 

Remove the Schrader filler valve tool and upper tooling valve. 

Note: Top off any excess fluid back into the port. 

Plug back in the brake port. 

Remove the gap tool. 

Remove the vacuum hand pump and apply air back to the rotary unit. 

Using the MDI program below, use this program to cycle the brake for 5 minutes. 

 M10; //Engage Brake

G04P10; //Dwell 10 seconds 

M11;//Disengage Brake

G04P10;//Dwell 10 seconds

M99;//Repeat Program

Check the diagnostic page to ensure the pressure switch changes state when the brake is toggled on and off. “CH 4 [A] Axis Brake Air Pressure”

    a. Brake ON = 1

    b. Brake OFF = 0

Put the front cover back on the unit. Be sure the O-ring seal is properly seated in the groove.

This O-ring keeps coolant and other fluids out of the rotary. If the O-ring is not properly seated or is damaged Coolant may get into the unit and damage it.

The right side of the image shows what a well-placed O-ring looks like and the left side of the image shows what an incorrectly place O-ring might look like.

When the O-ring is properly placed in its groove it should only be slightly higher than the area around the groove.

If is significantly above then the O-ring may not be properly placed or may be damaged. If it is below the area around the groove then it might be damaged.

If the O-ring is damaged then it needs to be replaced. Once the O-ring is seated properly and everything is clean screw the front and back covers on.