Service Home Built-In Rotary - Hydraulic Rotary Brake Booster - Troubleshooting Guide - NGC
Last updated: 06/16/2022

Hydraulic Rotary Brake Booster – Troubleshooting Guide - NGC

Introduction

  1. Solenoid valve connector
  2. Solenoid valve
  3. Air tube
  4. Pneumatic piston
  5. Brake booster
  6. Piston
  7. Return springs
  8. Hydraulic line
  9. Hydraulic pressure switch
  10. Hydraulic fluid reservoir
  11. Switch for the reservoir fluid

Symptom Table

Symptom Possible Cause Corrective Action
Alarm 4011, 5.4011, 6.4011, 7.4011 ROTARY BRAKE ENGAGEMENT FAILURE Air not connected. Check air connection. 
Air in the brake. Bleed the brake.
Pressure switch failure. Check the pressure switch.
Faulty solenoid. Test the solenoid.
Damaged brake booster seals. Use the bleed tool kit to check for pressure.
Air cylinder is seized. Repair the cylinder shaft.
Backlash. Poor surface finish. Air in the brake. Bleed the brake.
Faulty solenoid. Test the solenoid.
Damaged brake booster seals. Use the bleed tool kit to check for pressure.
Alarm 4003 or 6.4003 Rotary Brake Release Failure Air cylinder does not have the return line installed Install air line, refer to Rotary - Hydraulic Brake Booster Retract Air Line - Installation.
Pressure switch failure. Check the pressure switch.
There is hydrualic oil leaking below the platter. The rotary brake seal may be damaged. Replace the rotary seal.  Refer to the Rotary Brake Seal kit.  

Air In The Brake

Corrective Action:

If air gets into the brake system, the brake does not generate the correct pressure. You must bleed the brake system to remove the air. Use bleed tool T-0062A for EC1600, T-0062 for UMC.

Machines made before November, 2016 may need to reconfigure the reservoir feed hose. Refer to EC-1600, UMC-750 - Hydraulic Brake Booster - Replacement for more information.

Refer to:

Pressure Switch

Corrective Action:

The machine monitors a pressure switch to ensure the brake is holding pressure when activated. Do these steps to test the pressure switch.

  • Zero return all axes. Push [EMERGENCY STOP].
  • Disconnect the sensor cable from the B-Axis booster unit.
  • Connect the leads from a digital multimeter to the sensor contacts [1].
  • Release the [EMERGENCY STOP].
  • Manually activate the solenoid to unclamp the brake.
  • The multimeter shows OL (open) when the brake is clamped, and 0.1 to 0.4 Ohms when it is unclamped.
  • If there is air in the brake system, the brake does not generate enough pressure to activate the switch. Properly bleed the brake before you replace the switch.

Solenoid

Corrective Action:

Use code M10 and M11  to clamp and unclamp the axis brake. Check for 120 VAC at the solenoid.

If the voltage is present refer to: Solenoid Troubleshooting Guide.

If the voltage is not present refer to:

Booster

Corrective Action:

Use the brake bleed kit (Haas P/N T-0062A for EC-1600, T-0062 for UMC) to check the system pressure. If you cannot build pressure, 400-425 psi (27.6 - 29.3 bar), or, if the pressure drops, the booster may have damaged seals. If the oil level in the reservoir consistently drops, the brake is leaking internally. Refer to UMC-750 - B- and C-Axis Brake Booster - Replacement for more information.

Air Cylinder

Corrective Action:

Remove the air cylinder from the brake booster body.

Push the air cylinder piston shaft [1] into the retracted position. Remove the rear air fitting.

Use a small diameter rod (.375” (10 mm) or smaller) [2] to push the piston assembly to the extended position.

Use a stone to remove any burrs or high spots on the shaft.

Use your hand to move the shaft back and forth. It should move freely.