How To: Know When to Change Brush Blocks

As part of the AC power supply to the rotating gantry section, brush blocks play a critical role in the operation of your Aquilion CT scanner.


Brush blocks are used to transfer 200V AC from the stationary gantry frame to the rotating gantry frame through a large current slip ring (see pictures). In conjunction with the large current slip rings (LCSR), the brush blocks carry the three-phase AC voltage from the stationary section of the gantry to the rotating section.


A clean and properly maintained power supply will contribute to the reliability and longevity of the CT system.

Aquilion Brush Blocks

Q: How do you know when to change brush blocks?

A: Brush Blocks should be replaced when any brush tip has 1mm or less remaining from the limit line as indicated in the diagram and image below.

As the gantry rotates, the brush tips wear, and abraded material builds up on the slip ring and the mold surface. During slip ring maintenance, which should occur every three months, the brush blocks must be removed, cleaned, and inspected. During this time, it is ideal to evaluate the brush blocks for replacement using the limit line reference.

For consistency and uniformity, we strongly recommend replacing all four brush blocks at one time. This may help avoid additional downtime or a service call at a later date.

Aquilion Brush Blocks

Example of Brush Blocks that are worn and should be replaced:

Aquilion Brush Blocks

Example of New Brush Blocks:

Aquilion Brush Blocks

To replace the brush blocks, you’ll need the following tools:

  • Digital voltmeter
  • #2 Phillips screwdriver
  • #3 Phillips screwdriver
  • Torque wrench with a setting of 4.4Nm
  • 5mm Allen bit
  • Vacuum cleaner
  • Lint-free rags
  • Brush block alignment tool 
  • Disposable gloves and mask

What other parts may need attention during brush block replacement?

  • Large current slip ring (LCSR) – check for even wear, scratches, and burrs.
  • Ensure the inside of the dome cover and the sliding rear cover are clean. Replace any packing tape that is loose or coming off from the inside of the dome cover.
  • If any cable labels are loose or coming off, remove them and use a permanent marker to label the cable.
  • Clean behind the brush block mounting arms.
  • If the SURECOM data transfer system is used, clean the UPLINK antenna after performing slip ring maintenance.

Aquilion Brush Blocks

Remember! As a leader in the Canon/Toshiba CT replacement parts and tubes market, Richardson Healthcare is proud to offer brush blocks that can stand side-by-side with the OEM product – at less than half the OEM cost.

These brush blocks are compatible with Aquilion 4- through 64-Slice CT platforms and may also be referred to as part numbers BSX77-3487 or RELL43000524.


These pictures are taken straight from our proprietary training materials, which include helpful step-by-step procedures, troubleshooting guides, detailed pictures, and real-world tips from decades in the field.


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