Generac/Magnum CH&E Replacement Parts 2" & 3"

CH&E pump parts for the 2 inch 5400 and 6400 Series and the 3 inch 5500 and 6500 Series diaphragm pumps, including rebuild kits, flap valves, gear case parts, and drive adapters. Many of these also serve as Generac water pump parts for Generac Magnum MCP pumps. Match your model number below to find the right fit.

The right CH&E pump parts get a worn diaphragm pump back to work fast, but only if they match your series, your housing, and your drive. Is your pump losing suction in the middle of a dewatering job?

This page shows how the four CH&E pump series line up, which CH&E repair parts carry over between them, and what to replace first when output drops.

Which CH&E Pump Parts Do I Need?

The CH&E pump parts you need depend on three things: port size, housing material, and drive type. The 5400 and 6400 Series are 2 inch pumps, and the 5500 and 6500 Series are 3 inch pumps. Aluminum and cast iron versions share most internal parts, but their wetted-end parts are different.

CH&E Diaphragm Pump Series at a Glance

Start with the model number on the pump tag. The first two digits tell you the series.

For every reference number on the smaller pumps, use the 5400-6400 parts breakdown.

The 5500-6500 parts breakdown does the same for the 3 inch pumps, including the skid and wheel mounting hardware.

Which Parts Are Shared Between Aluminum and Cast Iron Pumps?

Aluminum and cast iron CH&E pumps of the same size share most of their internal diaphragm pump parts. That makes spare parts easier to stock if your fleet has both.

Parts That Fit Both Housings

• Connecting rod and connecting rod bearing
• Gears and gear case parts
• Bearings and lip seals
• Diaphragm
• Flap valve assemblies

Parts That Change With the Housing

• Suction connection
• Discharge connection
• Water box
• Diaphragm bottom

These wetted-end parts are made for one housing material only. Check whether your pump body is aluminum or cast iron before you order them.

Flap Valves and Rebuild Kits

The diaphragm and flap valves wear out first, especially when the pump moves sand, silt, or slurry. Every pump in these four series uses two flap valve assemblies.

Choosing a Flap Valve Material

If you are not sure which to pick, Neoprene is the most versatile choice for standard dewatering.

Why a Full Rebuild Kit Often Makes Sense

A rebuild kit, also sold as a diaphragm pump repair kit, includes the diaphragm, the flapper valve assemblies, and the hardware for a full fluid-end rebuild. Replacing every wear part at once lowers the chance of a second failure right after service.

Kits for the 2 inch pumps come in TPE, rubber, Neoprene, Buna-N, and Viton. To compare compounds before you order, see our CH&E replacement diaphragms page.

Drive Adapters and Pinions

CH&E diaphragm pumps can run on gas engines, electric motors, or hydraulic motors. Each drive needs the correct adapter and pinion for its shaft.

Measure the bore and keyway on your old pinion before you order. On 2 inch pumps, the last digit of the model number points to the right one.

Do These Parts Fit Magnum Mud Hog and Generac Magnum Pumps?

Yes, many CH&E parts also fit Magnum Power Products Mud Hog pumps and the Generac Magnum MCP 6437. Match your MCP model number to the CH&E series in this table.

If you are shopping for Generac water pump replacement parts on one of these units, order by the CH&E series in the left column.

For Mud Hog diaphragm sizes, the CH&E and Magnum diaphragms page lists the matching options.

What Changes the Price of CH&E Pump Parts?

Parts are quoted by model, so send us your pump series and the reference numbers you need. Two things move the total the most:

• Pump size: parts and kits for 3 inch pumps cost more than the same parts for 2 inch pumps.
• Single part or full kit: a kit costs more up front, but it covers every wear part in one order.

Request a quote with your model number and we will confirm what fits and what is in stock.

Should You Rebuild or Replace a CH&E Pump?

A rebuild is usually the better call when the housing and gear case are sound. Weak suction, low output, or leaking valves point to the diaphragm and flap valves, which a rebuild kit covers.

A cracked housing or a damaged gear case is a different story. When several major parts need replacing at once, compare the parts total with the price of a complete CH&E water pump before you order.

How to Keep a CH&E Pump Running Longer

• Inspect the diaphragm and flap valves every 250 hours, or sooner if output drops.
• Check the connecting rod bearing and grease fitting at every service.
• Look for leaks at the lip seals around the gear case.
• Flush the pump with clean water after moving abrasive or chemical fluids.
• Store the pump with the diaphragm in a relaxed position.

Frequently Asked Questions

What are the components of a diaphragm pump?

The components of a diaphragm pump fall into two groups: the wet end and the drive end. On a CH&E pump, the wet end includes the diaphragm, two flap valve assemblies, the water box, and the suction and discharge connections. The drive end includes the connecting rod, gears, bearings, seals, and the adapter and pinion that join the pump to its engine or motor. Wet-end parts wear fastest because they touch the water and solids.

What are some common problems with diaphragm pumps?

Common problems with diaphragm pumps include weak suction, low output, and leaks. On CH&E pumps, these usually trace back to a worn diaphragm, flap valves that no longer seal, or lip seals leaking around the gear case. Sandy or abrasive water speeds up that wear. A dry connecting rod bearing can also cause noise and heat, so check the grease fitting every time you service the pump.

How do you rebuild a diaphragm pump?

To rebuild a diaphragm pump, shut it down, drain it, and open the wet end to reach the diaphragm and flap valves. Replace the diaphragm, both flap valve assemblies, and the hardware from a rebuild kit that matches your series. Inspect the connecting rod bearing and seals while the pump is open. Then reassemble it, tighten every fastener to spec, and test it with clean water before it goes back on the job.

Where can I find a CH&E pump parts diagram?

You can find a CH&E pump parts diagram on the parts breakdown page for your pump series. Our breakdowns for the 2 inch 5400-6400 pumps and the 3 inch 5500-6500 pumps show an exploded view with numbered parts. Find the model number on your pump tag first. Then match each reference number on the diagram to the part number in the list before you order.

Order From a Master Stocking Distributor

Ken's Distributing Company is a master stocking distributor of water pumps and repair parts, with worldwide shipping.