10001-02016 Comet Pump MC25 Diaphragm Pump Rebuild Kit

What Is the 10001-02016 Rebuild Kit?

The 10001-02016 is a Comet OEM rebuild kit for the MC25 series diaphragm pump, featuring Buna rubber main diaphragms. The MC25 is a low-pressure positive displacement pump commonly used in agricultural sprayers, turf care equipment, and other low-pressure liquid transfer applications. This kit includes the wear components required to restore pump performance during routine service intervals.

Buna vs Desmopan — Which Diaphragm Material Do You Need?

The 10001-02016 kit uses Buna rubber diaphragms, which are well suited for water-based applications, fertilizers, and most general-purpose spraying. If you are running more aggressive chemistries — including certain herbicides, pesticides, and solvent-based formulations — consider the Desmopan diaphragm version of this kit (Comet 5026.0347.00) for improved chemical resistance and longer service life. Always check chemical compatibility against the diaphragm material before selecting a rebuild kit.

Why Is My Diaphragm Pump Losing Pressure or Showing Milky Oil?

Diaphragm wear typically presents as milky or grey oil in the crankcase sight glass, indicating that pumped fluid has crossed a ruptured diaphragm into the oil bath. Worn or fouled valve assemblies present as loss of prime, reduced flow output, inability to build pressure, or pulsation irregularities. O-ring failure presents as external weeping or visible drips at manifold joints. Comet recommends replacing diaphragms every season or every 500 hours of operation as preventative maintenance, whichever comes first, to prevent in-service failure and protect downstream system components.

Service Notes

When servicing the pump, drain the crankcase oil before disassembly, inspect valve seats for pitting or debris, ensure all o-ring grooves are clean before reassembly, and torque manifold fasteners evenly in a cross pattern to specification. Refill with the correct grade of pump oil after rebuild.

What's Included in the 10001-02016 Kit

• 2 x 1800.0020 Buna Diaphragms
• 1 x 1800.0033 Accumulator Diaphragm
• 4 x 1212.0004 Valve Assemblies (includes o-rings)
• 4 x 1210.0052 O-Rings

Specifications

• Part Number: 10001-02016
• Diaphragm Material: Buna rubber
• Type: Diaphragm, valve, and o-ring repair kit
• Application: Comet MC25 Diaphragm Pump
• Service Interval: Every season or 500 hours
• OEM Replacement: Yes
• Manufacturer: Comet Pumps

Cross-Reference Part Numbers

• Comet: 10001-02016

Compatible Pressure Washer Pump Models

The 10001-02016 rebuild kit is a direct fit for the following Comet diaphragm pumps:

• Comet MC25
• Comet MC25-115V

Related Parts

• 5026.0347.00 — Comet MC25 rebuild kit with Desmopan diaphragms (for aggressive chemistries)
• 5026.0116 — Comet MC25 complete rebuild kit (includes additional gaskets and hardware)
• Pump Oil — Recommended for refilling the crankcase after rebuild

Always verify compatibility with your specific pump model before ordering. If you need help identifying the correct part, text us a photo at 269-447-0412 or call 1-269-685-4123.