AirCoat 423 Fluid Pump Assembly

How the AirCoat 423 Fluid Pump Draws and Pressurizes Coating

The Titan AirCoat 423 Fluid Pump Assembly is the stainless-steel displacement pump that draws coating from the siphon system, traps material inside its pumping chamber, and sends it under pressure toward the high-pressure filter and spray hose. The air motor drives the piston rod through Titan 0533441 coupling pin, producing alternating intake and discharge strokes.

Titan 0533401 pump block contains the upper packing system. The upper stack uses Titan 0533402 female gland, three 0533403 leather V-packings, two 0533404 PTFE V-packings, 0533405 male gland, and 0533406 upper packing spring. These components seal around Titan 0533410 piston rod while allowing controlled reciprocating movement.

Titan 0533409 cylinder forms the pump’s working bore and is sealed at both ends by four Titan 0533408 PTFE O-rings. The piston assembly uses Titan 569-021 5/16-inch outlet ball, 0533412 retainer, 0533413 piston seat assembly, and the lower packing stack. The lower stack contains Titan 0533419 male gland, three 0533420 leather packings, two 0533421 PTFE packings, and 0533422 female gland.

At the pump inlet, Titan 0533418 foot valve assembly contains Titan 0533414 ball cage, 0533415 ball pin, Titan 51519 three-quarter-inch inlet ball, and Titan 0533147 ball seat. This inlet valve opens during the intake stroke and closes during the pressure stroke to prevent coating from returning to the material container.

Titan 0533926 Fluid Pump Service Kit includes diagram items 2–4, 7, 10, 15, 18–21, coupling pin 21, and Loctite sealant 426-051. This covers the glands, leather and PTFE packing sets, PTFE cylinder O-rings, outlet ball, inlet ball, lower packing components, and coupling pin. The pump block, spring, cylinder, piston rod, retainer, piston seat, ball cage, ball pin, ball seat, foot valve housing, and Titan 0533598 washer are separate inspection items.

The pump requires service when coating leaks excessively from the upper packing area, pressure output declines, or the pump strokes faster in one direction. Accurate diagnosis depends on stroke direction: abnormal behavior on the upstroke typically points toward the piston valve or lower packing system, while abnormal behavior on the downstroke commonly indicates an inlet or foot-valve problem.

Identify the symptom

Separate leakage, weak output, priming failure, and directional stroke problems.

Locate the valve system

Determine whether the issue belongs to the piston valve or foot valve.

Check kit coverage

Confirm whether Titan 0533926 contains each required wear component.

Inspect hard parts

Check the rod, cylinder, block, spring, seats, cage, pin, housing, and washer.

Maintenance Practices That Protect the Fluid Pump

• Relieve fluid and air pressure before disconnecting or opening the pump.
• Use Titan Piston Lube 314-480 at the upper packing area.
• Do not substitute ordinary oil, water, or solvent for packing lubricant.
• Keep the siphon tube and inlet screen clean to prevent cavitation.
• Inspect piston-rod and cylinder chrome for grooves, dents, or wear.
• Soak leather packings in hydraulic oil before assembly and lubricate O-rings.

Match the Fluid Pump Callout Before Ordering

Identify the affected stroke, packing stack, valve system, or hard part, then confirm whether Titan 0533926 includes the required component.

• Titan part number
• Fluid-pump callout
• 0533926 service kit
• Stroke-direction symptom
• Component name