• Bilge Pumps - How to Make Servicing Them Easier

    The thought of servicing a bilge pump is enough to make even the most savvy mechanic shiver. By their nature it is hard to access them on most boats. With this bracket assembly we will make that job much easier.
    You will need a piece of aluminum stock 6 inches wide, at least 12 inches long and approximately 3/8 inch thick. The actual length will be determined by the mounting method you choose as we discuss below.

    Step 1
    Determine which mounting method will work best for your boats configuration. The diagram below shows the two most common methods.

    Attachment 170

    In the example above notice that bracket 1 is bolted to the side of the bilge, while bracket 2 is bolted onto the top of the bilge. The ease of access to the bilge will determine which method you choose. Ideally bracket 2 is the easiest to install/remove in most cases but is a bit tougher to make. Regardless of the bracket style you choose, make sure you seal the bolt hole with a suitable sealant to prevent water ingestion into the core of your boat.

    Step 2
    Now that you have chosen the bracket style that works best for you, determine the space needed for the bilge pump and float assembly and mark the bend point.

    Attachment 171

    Bend the bracket 90 degrees along the line and once again check the fit of the bilge pump and float assembly to ensure they have adequate room.
    If you chose to use bracket 2, you have an additional bend to perform. It is best to place the bracket in its desired mounting position in the bilge and mark the location of the final bend. In most cases you will want the bilge pump and float assembly sitting on the bottom of the bilge, but if you are designing a backup bilge pump you may want the float to trigger at a higher water level. If so hold the bracket the desired height above the bilge floor and mark the bracket at the bend point. Perform the final 90 degree bend in the opposite direction and check the fit.

    Step 3
    Once all bends are complete and the bracket fits in the desired location, mark and drill the holes to mount the bracket to the bilge. Normally 1/4 inch lag bolts appx 1 inch long will be adequate for mounting purposes (use a bit slightly smaller than the lag bolt size). Temporarily install the bracket with the lag bolts to check for proper fit and orientation.

    Step 4
    Remove the bracket and mount the pump and float switch. Mount the pump on the inside closest to the bend to prevent undue stress on the bracket. Mounting the pump and float switch can be accomplished with either stainless steel bolts or with aluminum rivets if so desired.

    Step 5
    Mount the bracket into the bilge, seal the bolts, connect the hoses and the wiring.

    Attachment 172

    Attachment 173

    The pictures above are from a completed assembly that I have used on my boat for 3 years now and has worked well.


    Comments 8 Comments
    1. Dan's Avatar
      Dan -
      My Attwood V500 snaps into a base that is rivited into the wall of the boat. Does anyone know of a bilge pump that would fit in the same base?
    1. TimG's Avatar
      TimG -
      I am not aware of one, maybe other Attwood models will.
    1. greenghost39's Avatar
      greenghost39 -
      Great Tim
      Thanks m8 that bracket idea is brilliant
      My pumps were just laying in the bilges from the previous owners.
      And if it wasn't for the fact I'm rebuilding the deck and engines .
      You would never be able at sea to get to pumps.
      The other thing I noticed was the automatic pump wire wasn't connected "yikes"
      So I'll be doing your trick.
      On my boat
      I've separated and made a water tight bulkhead amidship also so that if by chance it should flood the cabin and Eng comp are separate giving you half a boat to float lol each compartment fwd & aft has its own pump
      Also any fumes from possible leaks won't enter the cabin
      Thanks again Tim the brackets are great
    1. TimG's Avatar
      TimG -
      I like the separate bulkhead idea, mine have weep holes that feed back to the stern but I would prefer them totally isolated.
    1. limacina's Avatar
      limacina -
      You know to improve on your better mouse trap, I'd add another 5" of aluminium beyond the switch and bend that up to protect the switch from random hoses, bottles, and junk in the bilge. Basically box it in, open on two sides.
    1. TimG's Avatar
      TimG -
      That would definitely help, I also had someone suggest a stainless cage around them to keep whatever from getting in there and disabling the switch.
    1. captmick's Avatar
      captmick -
      Quote Originally Posted by TimG View Post
      That would definitely help, I also had someone suggest a stainless cage around them to keep whatever from getting in there and disabling the switch.
      I'm not the 'someone else', however I built a very similar design, multi-part, for under the coupler to V-drive (lowest point in Pearson P39) that can be disassembled and reassembled due to confined space requirements for either access, repair or replacement. Also took out some left over rabbit wire cage material and nippers; built a little "switch protection cage" (many of which are for sale for stupid expensive money), took bailing wire to all the seams wrapping same to close it up pretty securely, and then sprayed the whole fabrication about 12x with rustoleum cold galvanizing compound. Attached over installed switch, mounted to block of starboard, 1.5" higher than adjacent Bilge Pump (Rule 1500) with S/S fender washers and screws. Took about a day although most of the time was spent 'waiting for paint to dry', while doing other projects. 5 yrs later it still performs excellently in preventing flotsam & jetsam (down to and including haphazardly clipped zip ties and plastic jacketing from stripped wires, etc.) from fowling the operation of the switch. Cheaper than a 'S/S' cage, and far cheaper than an emergency pump out from the towing services!

      Everyone should always KNOW (and THINK ABOUT/CONTEMPLATE) that Every SINGULAR Item that winds up in Your bilges is going to leave by 1 of three methods:
      1-By YOUR Hands either grabbing it, or in a bucket.
      2-By Way of getting sucked up, in to (and hopefully THROUGH) Your bilge pump, or unfortunately.....
      3-If it floats, By going over the side, from the interior of Your vessel after it SANK due to a faulty (or fowled) pump, switch or power supply.
    1. TimG's Avatar
      TimG -
      Your three rules for items leaving the boat are dead on!
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