Comet 2409.0023 Piston for MC25 Pump

Comet 2409.0023 Piston, Ø45 mm (MC20/MC25)

The genuine Comet Ø45 mm piston for MC20 and MC25 diaphragm pumps. Each pump has two pistons. The connecting rods drive them back and forth inside the piston sleeves, and the pistons flex the diaphragms to pump liquid. Replace a piston if it's scored, cracked, rusted or worn, which is common after a pump has run with water in the crankcase.

Each pump uses two pistons. If both show wear, replace them as a pair.

Specifications

Related Crankcase Parts

From the Comet MC20/MC25 parts breakdown. Call us at 602-371-1993 to order parts not linked below.

Frequently Asked Questions

Why do pistons wear out?
The most common cause is water in the crankcase from a broken diaphragm, which lets the internal parts rust. Comet's manual says that if you find water in the oil and can't rebuild the pump right away, drain the water and add oil (even used oil) to stop internal parts from rusting.

Should I replace anything else at the same time?
Inspect the piston sleeves and the connecting rods for wear or rust. If a broken diaphragm caused the damage, replace the diaphragms too, and refill with fresh oil after flushing out any water.

How do I prevent piston damage?
Check the oil regularly. Milky or watery oil means a diaphragm has failed, so stop the pump and repair it right away. Comet recommends checking diaphragms at the end of every season, and replacing them every year when using strong chemicals.

Related Products

• Comet 0205.0059 Connecting Rod Kit (2 Pieces)
• Comet 0003.0011 MC25 Pressure Accumulator
• All Comet MC25 Pump & Parts

Downloads

Download Comet MC20/MC25 Parts Breakdown

Download Comet Diaphragm Pump Instruction Manual