AODD Pump Repair: Air Motor and Center Section Assembly | OVELL

A diaphragm pump that stalls, cycles irregularly or loses flow does not always need a complete overhaul. Start by checking the operating conditions and identifying the affected assembly. This OVELL video shows the center section and air motor assembly of a 2 inch aluminum air operated double diaphragm pump (AODD pump), providing a visual reference for maintenance teams.

Watch the OVELL assembly video

The demonstration shows components such as gaskets, air valve covers, the sleeve, shaft and pilot spool being fitted. It focuses on the air-drive section; it is not a complete demonstration of diaphragm replacement, check-valve repair or every pump model's servicing procedure.

Before opening the pump

Identify the full model code and obtain the correct exploded drawing, parts list and maintenance instructions. Isolate and lock out the compressed-air supply, isolate the process connections and release trapped air and liquid pressure according to the site procedure. Drain and decontaminate the pump as appropriate for the liquid handled. A stopped pump can still contain pressure.

Prepare a clean work surface. Record component orientation during disassembly and keep small parts organized. Confirm replacement seals and gaskets against the model and material configuration; similar-looking parts are not necessarily interchangeable.

Diagnose the symptom before replacing parts

For a pump that will not cycle or cycles unevenly, check air pressure and available air flow at the pump, restrictions in the air line and exhaust, and the condition of the air valve and pilot mechanism. Inspection may reveal contamination, damaged seals or worn moving surfaces. Follow the model manual when cleaning or replacing components.

For reduced liquid flow, also check the suction line, liquid viscosity, discharge resistance and the fluid-side check valves. Low flow alone does not identify an air-motor fault. If process liquid appears at the exhaust, stop the pump and investigate the separation between the fluid and air sections before restarting.

Reassembly points illustrated by the video

Use the video to recognize the assembly layout, then follow the manual for the exact parts order and orientation. Inspect sealing faces, shaft and sleeve surfaces, and air passages. Replace damaged components and keep contamination out of the assembly. Fit gaskets flat and align passages correctly; do not force a component that does not seat properly.

Lubrication requirements, seal orientation, fastener sequence and tightening torques are model-specific. Do not estimate a torque from the power tool shown in the video or copy a setting from another pump size. Use the specified lubricant and a suitable torque tool where required by the manual.

Checks before returning to service

Confirm all parts, covers, guards and connections are fitted and that the installation is ready for a controlled test. Restore the air supply gradually as instructed by the manufacturer, keeping within all equipment ratings. Check cycling, air and liquid leakage, abnormal noise and the delivered flow under the actual operating conditions. Stop and reassess if anything is abnormal.

Record the replaced parts, inspection findings and test results. Recurring faults should prompt a review of air quality, operating duty and material compatibility, rather than repeated parts replacement alone.

Get the correct OVELL repair information

Send OVELL the full pump model, serial information, operating conditions, fault symptoms and clear photographs. For model-specific procedures, consult the product manuals. Explore the aluminum diaphragm pump range for available configurations, or contact our team for parts identification and maintenance support.

Explore the OVELL diaphragm pump range

The OVELL pump assortment below presents several pump configurations. Select each pump and its replacement components for the actual liquid, installation and operating requirements.