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4505 / 4507 / 4511 Installation Instructions
SAVE THESE INSTRUCTIONS
Form Number 69370 Rev. C 03-10
Sahara Series Automatic
This product carries the standard Attwood three-year warranty.
www.attwoodmarine.com or Product Catalog for details.
Read all instructions carefully before installing and using this product.
This pump is sealed and, therefore, submersible. However, the
electrical wire connections must not be submerged. For extra
protection, coat the butt joints and adjacent wire ends liberally with
liquid electrical tape such as MDR
0 ft. 3.3 ft. 6.7 ft. 10kPa 20kPa
Head Head Head Head Head Max Head
Part Amp GPH/ GPH/ GPH/ LPH/ LPH/ (ft.@13.6v/
Num. Model Fuse amps amps amps amps amps kPa@12v)
4505 S500 2.0 500/1.5 350/1.4 200/1.4 1136/1.2 598/1.2 9'/24
4507 S750 5.0 750/3.0 625/2.8 450/2.8 1817/2.5 1306/2.5 16'/36
4511 S1100 6.0 1100/4.0 970/3.8 750/3.8 3104/3.3 2328/3.3 11'7"/28
WARNING: To prevent injury, always disconnect the power
source when installing or servicing any electrical product.
use pump to remove gasoline, oil or other flammable liquids.
Always use the fuse amperage rating specified for your pump model.
Failure to do so could result in serious personal injury or fire hazards.
Attwood bilge pumps are designed to exhaust
They are not intended to prevent rapid accumulation of
on-board water due to rough weather, hull damage, and/or other
unsafe navigational conditions.
• Hose and thru-hull fittings, available separately from Attwood:
Sahara Model 4505 and 4507–
3/4" I.D. hose: Attwood No. 4199 (includes 2 clamps)
3/4" I.D. thru-hull: No. 3873 (straight), No. 66541 or 66547
(stainless steel straight), No. 3877 (90°), or No. 3878 (double-end)
Sahara Model 4511–
1-1/8" I.D. hose: No. 11551 (clamps not included)
1-1/8" I.D. thru-hull: No. 3874 (white), No. 3874A (black) or
No. 66543, 66549 (stainless steel), or No. 3879 (90°)
• Two (2) hose clamps suitable for (3/4" or 1-1/8") hose.
• AUTO/OFF/MANUAL dash-mounted control switch
(Attwood No. 7615A).
• In-line fuse connector (Attwood No. 14341) and appropriate
• Three (3) stainless steel #6 x 1/2" self-tapping screws, round
or pan head. Use a #32 drill bit for pilot holes.
• Four (4) wire butt-connectors for 16-gauge wire.
• Two (2) insulated spade terminal connectors for 16-gauge wire.
• Suitable means to make electrical connections waterproof.
• Cordless drill.
(LPH=Liters Per Hour)
(GPH=Gallons Per Hour)
• 1/2"-thick marine plywood block (slightly larger than pump base).
• Waterproof adhesive (epoxy, silicone adhesive, or fiberglass
resin) to mount block.
• 16-gauge wire (brown and black).
PUMP MOUNTING INSTRUCTIONS
WARNING: Remove the pump mounting base (See Figure 3).
Remove the foam block that supports the float during shipping.
Failure to do this prevents the pump from starting when water
1. Make sure the hull thickness is at least 1/2" thick. If not, place a
block of 1/2" marine plywood (slightly larger than pump base) in
the lowest part of the bilge. Be sure that the pump cover can be
removed for cleaning in this position. Glue the plywood to the
hull with a waterproof adhesive (epoxy, silicone adhesive, or
fiberglass resin). See Figure 1.
2. Position the pump in the lowest part of the bilge on a flat, level
surface (on the plywood block if it has been installed) with the
outlet pointing toward the transom.
3. Be sure outlet nozzle is level. If pointed upward or downward,
an airlock may form in the pump. (See Figure 1.)
4. The float end of the pump must be level with or above the
pump end (See Figure 1). This prevents the pump from running
out of water while the float is still high enough to activate the pump.
5. Mark location of the three (3) mounting holes with a pencil
WARNING: When drilling holes do not drill through the hull!
6. Carefully drill two 1/8" diameter pilot holes in marked area and
drive a screw in each hole.
7. Slide hose clamps (one to clamp hose to the pump, the other for
the thru-hull connector) over end of the hose. Force hose over
the discharge nozzle of the pump. Install clamp.
8. Route hose on an upward incline to the thru-hull connector.
Avoid dips in hose that can trap water and airlock the pump.
Avoid putting excess tension on hose, which can damage the
9. Force the hose over the thru-hull barbs and clamp into place.
THRU-HULL CONNECTOR INSTRUCTIONS
If no thru-hull connector exists, choose a location for the fitting.
1. Position thru-hull fittings at least 12" above the water line to
prevent water from coming back into the hull. On sailboats,
mount the thru-hull high enough on the center of the transom
to be above the water line at all times.
2. Place fitting, if possible, on the same side as the steering wheel
so the driver can see discharge of water when the pump is
3. Drill hole to match outside diameter of the thru-hull
4. Place a small bead of suitable marine sealant around inside
of the thru-hull connector flange.
Pointing To Transom
Bottom Of Boat