Genuine Maytronics part · Brushes & Climbing Rings
Maytronics Rear Brush Assembly, Grey S2
Part number 99955380-ASSY · UPC 810071221712 · 1 year part warranty
Genuine Maytronics grey rear brush assembly for Dolphin Quantum, Dolphin Active 20 and Dolphin ADVANTAGE ULTRA.
$24.99 MSRP
Not stocked by Poolbots. Sold on Amazon as a genuine Maytronics part.
Ships from Amazon.com. As an Amazon Associate, Poolbots earns from qualifying purchases.
About this part
What it does and when to replace it.
This genuine Maytronics part replaces the grey rear brush assembly on compatible Dolphin robots and helps scrub pool surfaces. Part 99955380-ASSY is a standard brush, not an active brush.
Maytronics lists Dolphin Quantum, Dolphin Active 20 and Dolphin ADVANTAGE ULTRA among the compatible models. Match 99955380-ASSY to your robot's parts list before choosing a replacement. Poolbots does not currently stock this part, but Poolbots' pool experts can help verify fit by live chat or phone.
- Match the full part number, 99955380-ASSY, rather than choosing by grey color alone.
- If your model name differs from the listing, ask Poolbots' pool experts to verify fit.
Compatibility
Fits these Dolphin robots.
Confirmed by Maytronics' compatibility checker and each robot's own spare-parts list.
Also listed by Maytronics for: Dolphin ADVANTAGE ULTRA, Dolphin Quantum, Dolphin Active 20, Dolphin ADVANTAGE PRO, Dolphin Proteus DX4, Dolphin Triton PS, Dolphin Premium, Dolphin Proteus DX5i, Dolphin Triton PS Plus, Dolphin Active 30, Dolphin T35, Dolphin Explorer E30, Dolphin T45, Dolphin T55i, Dolphin Active 40, Dolphin Explorer E50, Dolphin SCOOP SMART, E30, Dolphin Evolution 30, Dolphin MAESTRO 30, Dolphin MR 30, Dolphin PoolBot PB30, Dolphin RUN 30, Superpool, Z1B, Dolphin WOLLY, POOLSTYLE 30, Dolphin SM 30, SX 30, Dolphin SCOOP COMFORT, E35, Dolphin Evolution 35, Dolphin MAESTRO 35, Dolphin PoolBot PB35, Dolphin E35i, Dolphin SCOOP DELUXE, E40i, Dolphin Evolution 40i, Dolphin MAESTRO 40i, Dolphin MR 40i.
Do it yourself
How to replace it at home.
Switch off and unplug the power supply.
Remove the robot from the pool and place it on a stable surface.
Follow your model's brush replacement instructions to remove the old rear assembly.
Install the replacement rear brush assembly as directed for your model.
Check that the assembly is secure before returning the robot to use.
Step-by-step answers for this kind of part
How do I replace the climbing rings on my Dolphin brushes?Video20 min
These steps apply to all Dolphin models equipped with climbing rings.
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Step 1: Soak the existing climbing rings Soak the rings in the pool, or leave them in water for 10 minutes. Make sure they are completely soaked before continuing.
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Step 2: Turn the robot over Take the robot out of the pool and place it upside down.
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Step 3: Check that the power is unplugged Confirm that the power supply is disconnected from the outlet before working on the brushes.
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Step 4: Release the brush With a flathead screwdriver, release both sides of the brush from their sockets.
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Step 5: Take out the brush Remove the released brush from the robot.
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Step 6: Remove the old rings Take the existing climbing rings off the brush.
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Step 7: Fit the replacement rings Let the new climbing rings soak in water until they are flexible. Work them onto the brush.
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Step 8: Reinstall the brush With the new rings in position, slide the brush into its sockets. Press it into place.
Brush removal and installation videos
These videos show how to remove and reinstall the brushes. Use them as a reference for steps 2-5 and 8.
M Line (DX3/Sigma/Nautilus CC Plus/Nautilus CC Supreme/M400)
M600 (Active 60, Explorer E70)
For help finding replacement climbing rings, contact Poolbots' pool experts by live chat or phone.
How do I replace the brushes on my Dolphin robot?Video30 min
Disconnect the power supply from the electrical outlet before starting. Find the front, middle, or rear brush section below, then follow the video and instructions for your model.
For help choosing a replacement brush, contact Poolbots' pool experts by live chat or phone.
Front brush
S50 (E10, E20/E25, Active 10, Cayman, Escape, Encore)
Replacement front brush: 9995544-ASSY.
- Disconnect the power supply from the electrical outlet.
- Turn the robot over so its underside faces up.
- Take the tracks off the robot.
- Use a flathead screwdriver to remove the wheel disk.
- Turn the wheel until you can see the drive gear's retaining screw through it.
- Loosen and remove the screw, then take out the white drive gear.
- Ease the old brush out gently.
- Slide the replacement brush into position. Put the drive gear back and secure it with its screw.
- Put the wheel cover and tracks back on.
- Turn the brush by hand to check that it moves smoothly.
S100 (Advantage, Proteus DX3, Saturn, Echo, Nautilus CC, Active 15, Cayman, Escape, Explorer E20)
- Disconnect the power supply from the electrical outlet.
- Turn the robot over so its underside faces up.
- Take the tracks off the robot.
- Use a flathead screwdriver to remove the wheel disk.
- Turn the wheel until you can see the drive gear's retaining screw through it.
- Loosen and remove the screw, then take out the white drive gear.
- Ease the old brush out gently.
- Slide the replacement brush into position. Put the drive gear back and secure it with its screw.
- Put the wheel cover and tracks back on.
- Turn the brush by hand to check that it moves smoothly.
S200 (E30, Advantage Ultra, Active 20, Quantum, T35, Triton PS)
- Disconnect the power supply from the electrical outlet.
- Take the tracks off the robot.
- Use a Phillips screwdriver to remove the four screws securing the brush.
- Lift out the old brush.
- Fit the replacement brush and secure it with the four screws.
- Turn the brush by hand to check for smooth movement.
S300 & S400
S300 (E35/E35i, Proteus DX5i, Active 30, T35/T45, Premium 40, Explorer E30, E40i, Active 30i, T55i)
S400 (E50i, Active 50, Explorer E50)
- Disconnect the power supply from the electrical outlet.
- Take the tracks off the robot.
- Use a Phillips screwdriver to remove the four screws securing the brush.
- Lift out the old brush.
- Fit the replacement brush and secure it with the four screws.
- Turn the brush by hand to check for smooth movement.
M400/M500 (Sigma, Oasis, Nautilus CC Supreme, Aquarius XL, C4)
- Gently push the brush out with a flathead screwdriver until it releases.
- Position the replacement brush where the old one sat.
- Press the brush inward until it is seated.
- Turn the wheels to check that the brush moves properly.
M250 (Nautilus CC Plus, Dx3, Zenit 20)
Follow the video for the front-brush replacement procedure.
Premier
Follow the video for the front-brush replacement procedure.
Middle brush
M400/M500
- Disconnect the power supply from the electrical outlet.
- Turn the robot over so its underside faces up.
- Remove the four screws securing the brush, one at each corner.
- Lift the brush out of the robot.
- Fit the replacement brush in the same position as the old one.
- Reinstall all four screws and tighten them.
Sigma
Replacement middle brush: 9995541-R1.
This middle-brush procedure applies to Sigma produced in 2026 or later.
- Disconnect the power supply from the electrical outlet.
- Turn the robot over so its underside faces up.
- Remove the four screws securing the brush, one at each corner.
- Lift the brush out of the robot.
- Fit the replacement brush in the same position as the old one.
- Reinstall all four screws and tighten them.
Rear brush
S200 (E30, Advantage Ultra, Active 20, Quantum, T35, Triton PS)
Replacement rear brush: 99955380-ASSY.
- Disconnect the power supply from the electrical outlet.
- Turn the robot over so its underside faces up.
- Take the tracks off the robot.
- Carefully free the brush from the notches on both sides, then remove it.
- Fit the replacement brush where the old one sat.
- Put the tracks back on both sides.
- Turn the brush by hand to check for smooth movement.
S300 & S400
S300 (E35/E35i, Proteus DX5i, Active 30, T35/T45, Premium 40, Explorer E30, E40i, Active 30i, T55i)
S400 (E50i, Active 50, Explorer E50)
Replacement rear brush: 99955380-ASSY.
- Disconnect the power supply from the electrical outlet.
- Turn the robot over so its underside faces up.
- Take the tracks off the robot.
- Carefully free the brush from the notches on both sides, then remove it.
- Fit the replacement brush where the old one sat.
- Put the tracks back on both sides.
- Turn the brush by hand to check for smooth movement.
M400/M500 (Sigma, Oasis, Nautilus CC Supreme, Aquarius XL, C4)
Replacement brush assembly: 99955340-ASSY.
- Gently push the brush out with a flathead screwdriver until it releases.
- Position the replacement brush where the old one sat.
- Press the brush inward until it is seated.
- Turn the wheels to check that the brush moves properly.
M600/M700 (Active 60, E60i, Explorer E70)
Replacement rear brush: 99955340-ASSY.
- Disconnect the power supply from the electrical outlet.
- Turn the robot over so its underside faces up.
- Take the tracks off the robot.
- Carefully free the brush from the notches on both sides, then remove it.
- Fit the replacement brush where the old one sat.
- Put the tracks back on both sides.
- Turn the brush by hand to check for smooth movement.
M250 (Nautilus CC Plus, Dx3)
Follow the video for the rear-brush replacement procedure.
M550
Follow the video for the rear-brush replacement procedure.
Specifications
Product Info
- Active Brush
- No
- Brush Type
- Standard Brush
General Info
- Warranty (years)
- 1
- UPC
- 810071221712
Questions
Maytronics Rear Brush Assembly, Grey S2, answered.
Will this rear brush assembly fit my Dolphin?
Confirmed models include Dolphin Quantum, Dolphin Active 20 and Dolphin ADVANTAGE ULTRA. Other models are also listed. Give Poolbots' pool experts your exact model name and part number 99955380-ASSY to help verify fit.
Is this an active brush?
No. Maytronics identifies 99955380-ASSY as a standard brush, not an active brush.
What warranty is listed for this part?
Maytronics lists a 1-year warranty for this replacement part.
Brushes & Climbing Rings
