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Support / Bob PetHair Plus / Replace the Front Wheel Sensor

Replace the Front Wheel Sensor

What You Need: (click to shop)


Phillips Head Screwdriver


Flat-Head Screwdriver


Front Wheel Sensor




To replace the front wheel sensor on Bob PetHair Plus, you’ll need a Phillips head screwdriver, a flat head screwdriver, and a new front wheel sensor.

Before starting any repair on Bob, turn his side power switch OFF and remove his dustbin.

Then, flip Bob over onto a flat surface and remove his main brush using the flat head screwdriver.

Keep all removed screws and parts safely aside, as they may be needed for later reassembly.

Use a Phillips head screwdriver to remove the 6 screws on Bob’s underside that hold him together.

One screw on each side of the front wheel. One screw to the right of the main brush motor.

One screw on each side of the dustbin. The final screw is in the brush compartment.

Bob’s cover is no longer secured, so hold the top and bottom together as you carefully flip him back onto his wheels.

Grip Bob’s cover from the back and lift up to expose the mainboard.

Slide the power inlet down and tuck it somewhere safe to avoid compressing its wires.

To detach Bob’s cover completely, disconnect 4 circuit plugs:

Two at the lower edge of the mainboard, near the wheels.

And two more at the top edge, near the bumper.

Bob’s cover is now completely detached and can be set aside for the rest of the repair.

To access the front wheel sensor, first remove the mainboard.

Disconnect all remaining 12 circuit plugs from the mainboard. Press the small tab on each circuit plug and pull to disconnect.

Remove 3 screws on the mainboard. Keep them aside for later reassembly. Now lift the mainboard out of Bob.

Remove the two screws securing the sensor onto Bob. Keep these screws closeby for later reassembly.

Remove Bob’s front wheel sensor from underneath him.

Pull to remove the wheel and attach it to the new sensor.

Then, place the new sensor in the empty space.

Re-install the two screws and you’re ready to replace the mainboard.

Align the holes in the mainboard with the 3 screw posts on Bob’s interior.

Ensure that the mainboard sits flat before re-installing the 3 screws.
One screw goes in the middle of the mainboard, one in the top corner, and one in the lower corner.

Now reconnect all the circuit plugs correctly.

The order of plugs on the left side of the mainboard, from top to bottom, is:
A small plug with black and yellow wires.
A plug with two pairs of twisted wires
A plug with multi-colored wires for Bob’s left wheel,
A plug with blue and black wires.

The order of plugs at the top of the mainboard, from left to right, is:
A small plug with red and green wires
A wide plug with multicoloured wires,
Two empty spaces for now
And a small plug with black and orange wires in the top right corner.

The order of plugs on the right side of the mainboard, from top to bottom is:
A wide circuit plug for Junior’s power switch,
And a plug with black and orange wires for Junior’s power inlet.

For now, the bottom of the mainboard will have two open spaces on the very left.

Then, the order from left to right is:
A small circuit plug with a red wire,
One more open space,
A small plug with yellow wires,
And lastly, a plug with multi-colored wires on the very right.

Now you’re ready to begin re-attaching the cover.

Reattach all 4 circuit plugs connecting Bob’s cover to the mainboard.

2 connect to the top edge of the mainboard, and 2 more that connect to the bottom edge.

Remember to slide the power inlet back into its space on Bob’s cover.

Align the cover’s edges precisely. Then, flip Bob over onto a flat surface.
Ensure that no wires are compressed in the main brush compartment or visible at the edges of the bumper.

If so, take a step back and lift the cover to tuck the wires into the appropriate spaces.

Once the wires are all safely tucked away and Bob’s cover is aligned properly, reinstall all 6 screws previously removed from Bob’s underside.

Install the main brush and dustbin before your next use and Bob is completely re-assembled.

Turn the side power switch back on and congratulations! You’ve just replaced Bob’s front wheel sensor. Happy cleaning!