• Remove the coolant collector cover, surrounding sheet metal, and anti-rotation bracket that seats around hydraulic actuator drain hose
• Lock the spindle to prevent it from rotating
• Break the screws [1] loose that connect the adapter to the actuator
• Power off the machine
• Disconnect the hydraulic lines [5] from the hydraulic actuator [2]. Note the clamp/unclamp hose and port orientation.  Mark the hose and port if necessary
  •  Note: Have plugs or baggies and rubber bands to cover the hoses to prevent hydraulic fluid from coming out and debris from getting in.  Keep the hoses pointed up and tucked away on the side of the spindle to prevent fluid from coming out
    
• Fully remove the rest of the screws and slowly remove the union and drawtube assembly
  •  Caution: The actuator is heavy and if dropped or banged it could receive permanent damage
    
  • Have a box or table nearby with padding to lay the actuator in and support the drawtube
• Note: You only need to remove the adapter if it's damaged and you are replacing it, otherwise leave the current adapter installed and only replace the actuator
  
  • Remove the adapter screws [3] that secure the adapter [4] to the spindle shaft.
  • If necessary, heat the adapter with a heat gun to release it from the spindle shaft [4] 

• If you need to replace the adapter, follow this step, otherwise skip to Step 3
• If you have a ST-20/25/30 - Please read the last section before continuing:

• The new adapters are a sweat fit to the spindle shaft.
• A hot plate will work best to uniformly heat the adapter
  •  Caution: Do not exceed 230 °F (110 °C) when heating the adapter
    
• Place the adapter smaller diameter face down on the hot plate
  • Caution: Be sure to use high temperature heat resistant gloves when sweat fitting the adapter
    
• When you install the adapter you must move quickly as the aluminum will cool fast
• With the adapter at about 230 °F (110 °C) on the hot plate - take one screw [1] and put it into the adapter washer [2] to have it ready
• With gloves on, using both hands, take the adapter and quickly slip it onto the shaft
• Press evenly on both sides, until you feel it seat  
• Rotate it until the hole patterns line up
• Take the screw and adapter washer and quickly run down the one screw into a hole
• Quickly run the rest of the screws down in a star pattern
• Torque the screws in a star pattern to ensure the adapter seats
  • Haas Torque Chart
• Then break the screws loose but leave them snug while the adapter cools
• Torque screws again once the adapter has cooled
• Once cooled measure the inner radial runout [3], not to exceed 0.001"
• Measure the axial runout [4], not to exceed 0.0005"
  • Production Tip: If you find that you're having a hard time getting the adapter to seat and have accepatable runout, then try the following.  After you slip the hot adapter on the shaft, snug all the screws down, and then lightly indicate the adapter on the inner radius [3] while using a plastic mallet on the outer diameter. When the runout is within spec, slowly torque all of the screws down in a star pattern being careful not to induce runout.
    

• Install the union and snug the screws
• Place an indicator on the steel strip [1], runout not to exceed 0.0005" 
• Indicate in if necessary
• Place an indicator on the coolant collector [2].  Rotate the union and measure how much the indicator deflects, not to exceed 0.001"
  • If the runout exceeds 0.001" please see the alignment section of the Lathe Vibration Troubleshooting Guide
• Torque the screws in a star pattern
  • Haas Torque Chart
• Re-install the hydraulic hoses
  •  Caution: Do NOT over tighten the hose fittings.  This could cause the aluminum housing to crack.
• Re-install anti-rotation bracket around drain hose
• Power on machine and test clamp/unclamp
• Run the spindle take a vibration test to ensure all components are aligned.
• Check results against Lathe Spindle Vibration Tolerances
• Re-install surrounding sheet metal and coolant collector box

Note: Add dielectric grease to all surfaces of the coolant collector seal ring.

• Optional: Replace drive sprocket if required when replacing the adapter plate
• Determine sprocket part number through HBC
• If you need to replace the adapter for the hydraulic union on a ST-20,25,30 - then see the following:
• Note: You do not need to replace the adapter when you are replacing the hydraulic actuator unless it has damage.
• For ST-20's, 25's and 30's the steps are the same as above, except if the adapter is a slip fit (has clearance), then the drive sprocket will also need to be replaced to allow for dimensional changes in the new hydraulic actuator adapter plate.
  • Machines built after 11/20/2018 will have sweat fit adapters and will not need the drive sprocket replaced.
    
• This section will only cover the drive sprocket replacement- See the previous section for section regarding the adapter plate and actuator.
• Break loose the motor mount plate screws [4]
• Loosen the nut on the tensioner block [3] and loosen the belt tension on the belt by turning the socket head cap screw (SHCS) counter-clockwise
• Remove the belt from the pulley
• Break loose the drive sprocket [1] screws
• Remove the drive sprocket
• Align the new drive sprocket hole pattern with the holes on the spindle lock [2]
• Install the screws and torque per the Haas Torque Chart
• Re-install the belt
• Re-tension the belt by turning the SHCS clockwise
  • Check belt tension with a Gates Sonic Meter per Haas Belt Tension specs
• Tighten the nut on the SHCS once tension is achieved
• Torque the motor mount plate screws per the Haas Torque Chart
• Always check the gap between the non-contact encoder read head and the encoder ring after re-setting belt tension
• Adjust the encoder gap at the high spot on the encoder ring if necessary

Refer to Coolant Collector Replacement - ST-20 - AD0432 for instructions regarding installing the coolant collector.