OEM Potted Heavy-Duty Solenoid for Double-Acting Hydraulic Pumps

The KTI 391-40 is a 12V DC potted heavy-duty solenoid harness designed for double-acting (power up / power down) hydraulic pump systems. It comes pre-wired with both up and down coils, a start switch, and a twist-lock quick-disconnect connector — eliminating wiring confusion on installation.

The fully molded (potted) construction seals the coils and wiring harness against moisture, vibration, and contamination, making it the factory-specification replacement for KTI double-acting power units.

📐 Specifications

🔍 What This Solenoid Does

The 391-40 is the complete solenoid harness assembly for KTI double-acting pump systems. It controls both the power up and power down hydraulic functions through two integrated coils — one for each direction. The pre-wired twist-lock connector plugs directly into the KTI pump tower, making replacement straightforward with no loose wires.

Common failure symptoms: pump clicks but won't move in one or both directions, or remote pendant buttons have no response despite a charged battery.

🛠 Verified Fitment & Brand Applications

This solenoid is used on trailers equipped with KTI double-acting hydraulic power units (power up / power down), including models from:

Dump Trailer Manufacturers Using KTI Double-Acting Units

• Load Trail
• PJ Trailers
• Lamar
• Diamond C
• Griffin
• Norstar Dump Beds
• Iron Bull (KTI-equipped models)
• Sure-Trac (select hydraulic models)
• Texas Pride (KTI power systems)

⚠ Important: Fitment depends on the trailer being equipped with a KTI double-acting pump assembly. This solenoid is for double-acting (power up / power down) systems only — not single-acting (gravity down) units. Always verify pump type before ordering.

💪 Key Features

✔ Pre-Wired Complete Harness

Both coils and start switch included in a single molded assembly — no loose wires, no guesswork. Connects to the pump tower via twist-lock quick-disconnect.

✔ Fully Potted (Molded) Construction

Sealed housing protects coils and wiring from moisture, dirt, and job-site vibration. Built for outdoor commercial use.

✔ Zinc-Steel Mounting Bracket

Rigid bracket ensures secure fitment directly to KTI hydraulic motor assemblies.

✔ Integrated Magnet Design

Built-in magnets provide reliable internal actuation and stable valve performance.

✔ Designed for Double-Acting Pumps Only

Specifically engineered for power up / power down hydraulic systems. Will not operate correctly on single-acting (gravity down) units.

🚛 In Stock & Ready to Ship

Restore full up/down hydraulic control with the KTI 391-40 potted double-acting solenoid harness.

Common Hydraulic Pump System Components

• View KTI DC36RA Hydraulic Pump
• View KTI 395-55 Pendant Remote
• View KTI 74-06 Extension Cord
• View KTI KWR-005 Wireless Remote

📋 KTI Catalog Data

• Type: Potted Heavy-Duty Solenoid — Double Acting
• Voltage: 12V DC
• Includes: Both coils, start switch, twist-lock quick-disconnect
• For: Double-acting KTI power units (Universal Manifold II & III)

🏭 About KTI Hydraulics

KTI Hydraulics Inc. — founded 1997 in Tustin, California. ISO 9001:2015 Certified. Every KTI power unit is 100% factory inspected and tested to stringent specifications before shipping. Inventor of the patented Universal Manifold® system used in dump trailers worldwide.

📞 Call/Text: 517-225-1991 🌐 AAATrailer.com

🔄 Cross Reference / Alternate Part Numbers

KTI 391-40 | KTI-391-40 | 39140 | OTP-391-40 | Potted heavy-duty double-acting solenoid harness

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