QED Environmental Systems Oil Pump AP4.5

Remove the bottom “spider” casting by unthreading it from the discharge tube

Visually inspect the fluid discharge pipe for scale build-up or debris

Visually inspect the float that slides up and down on the discharge tube for scale build-up or debris

Remove the float from the discharge tube by removing the small steel hairpin from the bottom spring cup

Clean the fluid discharge tube using a damp cloth. Soak in vinegar if necessary. Use non-stick cookware scour pads for tougher build-up

Clean both the internal and external surfaces of the float using a damp cloth. Soak in vinegar if necessary. Use non-stick cookware scour pads for tougher build-up. Remove and replace the float end plates as necessary

Clean the white plastic square control rod using an abrasive pad or a razor or utility knife

Clean the outer casing using a three-stone honing tool. Move the hone in and out a half dozen times or so, through each end of the casing

Re-assemble the AutoPump by following the steps above in reverse order

Disconnect the air supply from the pump

Remove the bolt at the bottom of the pump which holds the inlet screen in place (bottom loading pumps only)

Remove the three bolts at the bottom of the pump which hold the inlet in place

Remove the inlet from the pump’s casing by pulling it out

Twist and slide the casing down off the pump’s frame