Maruyama MSD41 Regulator Repair Kit

Maruyama MSD41 Pressure Regulator Repair Kit

The Maruyama MSD41 Regulator Repair Kit provides replacement components for servicing the pressure regulator on the Maruyama MSD41 piston pump. Designed for maintaining the regulator's internal valve mechanism, this kit includes a piston assembly, Viton O-rings, valve ball, spring, and cap screw.

When pressure regulation becomes inconsistent or internal regulator components become worn, replacing the affected parts may help restore proper regulator operation without replacing the complete assembly.

Key Features & Benefits

• MSD41 Compatibility: Designed for the pressure regulator used with the Maruyama MSD41 piston pump.
• Internal Regulator Components: Includes parts used in the regulator's pressure-control mechanism.
• Viton O-Rings: Includes two replacement O-rings for regulator servicing.
• Convenient Repair Kit: Combines multiple replacement components into one package.
• Alternative to Complete Replacement: Allows servicing of selected internal components when the regulator body and other parts remain serviceable.

What's Included in the MSD41 Regulator Repair Kit?

Each kit contains the following replacement parts:

Total Kit Contents: 6 individual replacement pieces.

Compatibility & Fitment

This repair kit is intended for the Maruyama MSD41 (3/4") piston pump pressure regulator.

The manufacturer's MSD41 parts diagram identifies the complete pressure regulator valve assembly as Maruyama part 546849.

Important: This product is a repair kit for selected internal regulator components. It is not the complete 546849 regulator assembly and does not include the regulator housing or adjustment knob.

Verify your pump model and regulator configuration before ordering.

Common Pressure Regulator Problems

Pressure regulator components should be inspected when experiencing symptoms such as:

• Spray pressure that fluctuates or becomes difficult to regulate
• Pressure that does not respond normally to regulator adjustment
• Internal regulator leakage or bypass issues
• Worn or damaged regulator seals
• Visible wear or damage to internal valve components

These symptoms can also result from other pump or spray system problems, including worn pump seals, restricted inlet flow, or damaged spray equipment. Inspect the complete system before determining which components require replacement.

Product Specifications

Installation & Maintenance Notes

Handle the piston assembly carefully during installation. The piston assembly is fragile and can be damaged if improperly handled or forced into position.

• Shut down the pump and relieve system pressure before disassembly.
• Identify the regulator components using the manufacturer's exploded parts diagram.
• Inspect the regulator body and other components for wear or damage.
• Install replacement components carefully, using appropriate service procedures.
• After reassembly, check for leaks and verify proper pressure adjustment before returning the equipment to service.

Maruyama MSD41 Parts Diagram

Use the manufacturer's illustrated parts list to identify regulator components and their locations. The pressure regulator exploded diagram appears in Section 2, pages 3–4 of the manual.

Download Maruyama MSD41 Pump Parts List & Diagram (PDF)

Need the Complete Regulator Assembly?

If the regulator body, adjustment mechanism, or other components are damaged beyond repair, replacing the complete regulator may be more appropriate.

Shop Maruyama 546849 Complete Pressure Regulator Assembly

Kit contents are based on the listed QSpray regulator repair kit. Confirm replacement part compatibility before installation.