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DMD/DM640 Series Dump Pump For Medium & Heavy Duty Dump Trucks, 6.40 cu in/rev, Mount, 3-Line Operation, 2000.00 PSI Relief Setting

Description & Features

The DMD/DM640 Series Dump Pump is engineered for medium and heavy-duty dump trucks providing robust performance and reliability. Featuring a 6.40 cu in/rev displacement and direct mounting it utilizes a 3-line operation to ensure hydraulic efficiency.

Built from rugged cast iron with high-strength alloy steel gears and shafts this pump offers durability and extended service life. Its pressure is regulated up to 2000.00 PSI with a built-in direct-acting relief valve which adds an extra layer of protection. The pressure-balanced wear plates help maintain pump efficiency across various operating ranges.

Designed to handle a maximum speed rating of 2400 RPM and a pressure rating of 2500 PSI the DMD/DM640 features a roller bearing pump structure that enhances load-carrying capacity. Each unit undergoes 100% factory testing to ensure reliable performance. The manual shift and built-in load check contribute to operational stability.

This model incorporates enhanced safety features including a neutral lockout safety cap for use with a pull-out cable and two extra-long studs for straightforward installation of a pump support bracket. The configuration includes 1-1/4 NPT inlet ports and 3/4" NPT pressure and return ports.

MPN: C1CN68

Supplier Part Number: DMD-25-Z-L-MS-20

Specifications

Circuit Type 3-Line	Direct Mount Rotation CCW	Displacement 6.40	Displacement 6.4	Brand Permco Inc.	Brand Permco	Pack Size 1.00	UOM EA	Features Replaces Commercial C102D251	Mounting Direct	Pressure Rating 2500	Rated Flow 46	Rated Flow 46	Relief Setting 2000	Remote Mount Valve Location --	Alternate Part Numbers Alternate Part Number C102, Alternate Part Number C1CN68, Alternate Part Number DMD-25-ZL-MS-20, Alternate Part Number DMD25ZLMS20, Alternate Part Number DSDMD-25-Z-L-MS-20, Alternate Part Number MI-02116974, Alternate Part Number MINO-00653X70082	Speed Rating 2400 RPM	Supplier Part Number DMD-25-Z-L-MS-20	Product Weight 63.00 lbs

Product Questions & Answers (3)

Question by: Glen H on Apr 22, 2025, 2:38 PM

pump says 3-line operation -- what's actually different about that compared to a regular 2-line setup on a dump truck?

Answer by: Customer Support on Apr 24, 2025, 1:36 PM

With 3-line operation, a third line runs from the pump's return port back to the tank. That return path lets oil that's displaced during cylinder retraction, or just recirculating while the valve is in neutral, flow back to tank instead of building heat inside the system. A metal sleeve gets installed in the valve inlet port to redirect that flow. It doesn't eliminate heat entirely, but it buys you more time. You can run the pump engaged with the spool in neutral for up to 10 minutes with a 3-line circuit before heat becomes a real concern. With a 2-line setup that number drops to 5 minutes, and the oil temp climbs about 7.5 degrees per minute while you're sitting in neutral. The 3-line circuit is the right call for medium and heavy duty dump work where idle time between raises is common.

Question by: Jimmy E on Feb 22, 2026, 6:43 AM

Reckon this'll bolt right up where my old Commercial C102D251 used to be?

Answer by: Customer Support on Feb 23, 2026, 9:47 PM

This Permco DMD/DM640 series pump is designed as a direct replacement for the Commercial C102D251. Just make sure your mounting and port sizes match up.

Question by: Cindy H on Feb 12, 2026, 3:40 PM

got a dump truck pump that’s runnin a 3-line setup. what size ports are on this one for suction and pressure/return?

Answer by: Customer Support on Feb 13, 2026, 3:51 PM

Porting is set up for a true 3-line circuit. The inlet (suction) is 1-1/4 NPT, and both the pressure port and the return port are 3/4 NPT.