CHECKING LIQUID-FLOW
THROUGH THE TA'S OUTLET SCREEN & VALVE

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INTRODUCTION

If you are interested in trying an experiment to determine if Scooba's Clean-Tank is capable of delivering liquid to the robot's pump-intake fitting, you could perform the procedure outlined below. If flow-through appears sluggish, back- flushing may help.

Procedure to Verify that Liquid Can Drain from the Clean Tank

All there is to this procedure is to manually open a check-valve to verify that contained liquid is free to drain from the CT. Enough instructions are provided to assist the mechanically challenged Scooba owner.

  1. Obtain / prepare a tool that can be safely (for the tank's parts), gently pushed into the hydraulic-connector's port for the purpose of slightly moving the check-valve at the upper end of the passage. Just to be certain about which passage is to be probed, here is a repeat view of it:

    Figure 1. Clean-Solution Feed-Coupling (duplicate use)

    The tool is to be a rod-shaped (e.g., the shaft from a cotton swab might work OK, or use a sharp knife to cut off the sharp end of a round toothpick -- where thickness is maximizing). The rod cannot block the passageway.
  2. Now, before using the 'tool', especially if a bit ham-fisted, you should calibrate the maximum amount of motion you should apply to the valve. The depth-calibration is very simple.
    1. Grasp the rod between thumb and index finder, place your thumb-nail at the top end of the vertical 'cleaning-solution coupling' (sticking out of the robot as shown in "Hydro-Pneumatic-Path", Figure 3).
    2. Then adjust the rod's vertical position so it just touches the black ring around the base of the lance -- while still maintaining nail contact.
    3. Then, holding that depth reference tightly, take the tool to the tank (capped if it contains liquid) and slide the tool into the bore of the hydraulic-connector until you sense it has contacted something mechanical.
    4. At that point, stop and assess the gap-size between your thumb-nail and the black ring at the base of the coupling-fitting. Memorize that magnitude, it represents the greatest movement you should impart to the vale during this test.
  3. Partially fill the Clean Tank with water, but leave its Cap unsealed. {With the Cap closed, flow will not maintain for long. Apparently the air-bleed valve (identified as Item-7 in "Tank Assembly Details", Figure 4) is too stiff to be actuated by gravity-flow of the water.}.
  4. Hold the partially filled TA horizontal, as it would be while in Scooba's working orientation. Hold it over a sink, then push the 'tool' into the coupling to open the check-valve. Water should flow out and down over your fingers.

If fluid does drain from the manually opened check-valve, the internal filter-screen and outlet passage are clear, and should properly gravity-feed solution to the pump's-intake.

When Liquid Fails to Drain, Try Flushing

If fluid fails to drain, it might be fixed by back-flushing the connector, its valve, and screen. Back-flushing involves forcing water into the CT by passing it through the fitting in the reverse direction. If that needs to be done, you might read the instructions in the 060219.0859 post. The author ("user") tells how to make some simple tools that are required to do the flushing. Be certain to use clean tools and water, you don't want any particles in this area, or in the tubing that heads to the Pump Assembly (since 'user' also advises forward flushing through the Pump Assembly -- all the way to the jets -- too).

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This page is currently maintained by G. Plews