CAT 345D / 349D Main Control Valve – China Remanufactured (323-7682)

Description

Detail Information

Note: The application information provided is for reference only. Please confirm the part number and compare it with the old component before purchasing. If you have any questions, please feel free to contact us.
It is worth choosing a product that features stable performance, high reliability, easy installation, and quick response.

1. Key Features & Benefits

• Professionally remanufactured to Caterpillar OEM specifications – This main control valve (OEM 323-7682, also cross-referenced with 493-7956 and 323-7681) has been fully disassembled, cleaned, crack-inspected, and rebuilt to meet Caterpillar’s original equipment specifications. Every critical component – spools, sleeves, springs, seals, O-rings, and relief valves – is either renewed or replaced with new, high-quality parts. The result is restored hydraulic performance at a fraction of the cost of a new genuine valve.

• The hydraulic “brain” of your 45–50 ton excavator – The main control valve is the central component that directs high-pressure oil from the main pump to the boom, arm, bucket, swing, and travel circuits. It governs every movement your machine makes – from a delicate grading pass to a heavy bucket curl. When this valve wears out, your machine loses precision, power, and responsiveness.

• Direct replacement for CAT 345D, 349D and 349D2 series – Specifically engineered for Caterpillar 345D, 345D L, 349D, 349D L, 349D2, and related 45–50 ton class excavators. Mounting flange, port configurations, and bolt patterns match the original Caterpillar specifications exactly – no modifications, no adapters. The valve consists of a right valve body and a left valve body bolted together as a complete assembly.

• Massive flow capacity for 45–50 ton class work – The CAT 349D hydraulic system generates a maximum flow of 734 L/min and operates at a main relief pressure of 35 MPa (≈5,076 psi) . The 345D is powered by the Cat C13 engine delivering 283 kW (≈380 HP). This main control valve is precision-engineered to handle this immense flow, providing the hydraulic power needed for fast cycle times, high bucket fill factors, and responsive multi-function operation – even when booming, swinging, and travelling simultaneously.

• Proportional pilot control for outstanding controllability – The pilot control valve operation is proportional to control lever movement, delivering outstanding controllability. This provides the precise, predictable machine response that CAT excavators are known for – critical for precision grading, trenching near utilities, and fine attachment control.

• Integrated main and line relief valves for circuit protection – Two types of relief valves are installed on the main control valve. The main relief valve limits pressure in the main hydraulic system. The line relief valve limits pressure built into individual cylinder circuits. This dual protection system safeguards your pumps, cylinders, hoses, and other hydraulic components from catastrophic over-pressurization.

• Optimized component layout for maximum efficiency – The main pumps, control valve, and hydraulic tank are located as close to each other as possible. This design makes it possible to use shorter tubes and lines between components, reducing pressure drops and friction losses. The hydraulic system utilizes each of the two hydraulic pumps to 100% of engine power under all operating conditions.

• Advanced tool control system compatibility – The 345D/349D series features a tool control system that is a combination of hydraulic and electrical systems controlling oil flow to attachments. The system consists of a machine controller and flow control proportional reducing valves. The machine ECM can retain up to ten different attachment setup programs, with up to four different spool control parameters included in one attachment setup type.

• Superior durability and contamination resistance – Utilizes high-strength alloy materials and precision-machined spools and sleeves with tolerances measured in microns to ensure minimal internal leakage and maximum control precision. Premium seals and O-rings are installed to withstand extreme pressures and temperatures.

• Direct bolt-on replacement – Mounting flange, port configurations, and bolt patterns are restored to original Caterpillar specifications. No modifications, no adapters – your mechanic unbolts the old valve and bolts this one in.

• Pre-shipment visual verification – Before packing, we send you detailed high-resolution photographs of the actual unit (mounting surfaces, port threads, castings, overall condition). You approve shipment – we never ship blind.

• Fast delivery – 5–8 working days lead time from our Guangzhou warehouse. Monthly supply capacity of 300 units, available for single-piece or bulk orders.

2. Applications

The remanufactured CAT 323-7682 main control valve is the hydraulic command centre for 345D and 349D series excavators used across the most demanding job sites:

• Large-scale open-pit mining – 45–50 ton excavators are the backbone of copper, gold, iron ore, and coal mining operations. The valve’s massive flow capacity (734 L/min) and high-pressure capability (35 MPa) deliver consistent digging force and smooth, responsive control hour after hour in remote mine sites where reliability is critical. The 345D is specifically designed for矿山等石方工程 (rock and mining applications).

• Quarrying & aggregates – Loading trucks, stockpile management, and material handling in granite, limestone, and basalt quarries. The valve’s high resistance to wear, pressure, and contamination withstands abrasive dust conditions, while the precision-machined spools provide smooth, responsive operation for precise bucket control.

• Heavy construction & infrastructure – Highway excavation, dam building, bridge footings, and large-scale earthmoving projects. The valve’s optimized hydraulic flow distribution enables simultaneous, coordinated movement of multiple functions – booming, swinging, and travelling – without power loss.

• Demolition & scrap processing – Shock loads, vibration, and sharp debris are routine in demolition yards and metal recycling facilities. The valve’s heavy-duty construction and high-strength alloy materials absorb these extreme conditions without premature wear.

• Equipment rental fleet – 45–50 ton excavators are high-value rental assets. A remanufactured main control valve offers predictable performance at a cost that makes proactive replacement financially sensible – avoiding costly mid-rental failures, towing bills, and customer complaints.

• Forestry & land clearing – Steep slopes, fallen timber, and uneven terrain demand reliable hydraulic control. The valve’s consistent pressure and flow output maintain stable power for saws, grapples, and mulchers.

3. Why Choose Hongtengda Parts

Since 2001, Hongtengda Parts has been a leading distributor of earthmoving machinery parts, serving customers across Southeast Asia, the Middle East, Africa, the Americas, and Oceania. Headquartered in Guangzhou’s Zhucun parts hub – one of Asia’s major distribution centres for construction machinery parts – we combine deep inventory, cross-brand knowledge, and reliable global shipping to keep your machines running.

What you get when you order from us:

• 25 years of heavy equipment parts experience – Since 2001, we have been the go-to supplier for repair shops, fleet owners, and wholesalers worldwide. We know the CAT 345D and 349D platforms inside out – the different hydraulic systems, control configurations, and production changes over the years.

• Remanufacturing that delivers performance comparable to new – Our remanufacturing process follows strict quality standards to ensure same-as-new quality and performance. Each main control valve is rebuilt using precision engineering principles, with all critical wear components replaced – not just patched or resealed. Every spool tolerance is examined and measured to ensure OEM specifications are met.

• 90% of our catalog in stock – Your main control valve sits in our Guangzhou warehouse, not in a supplier’s backlog. From hydraulic components to undercarriage kits, most orders are dispatched within 24 hours on fumigated, export-ready pallets.

• One supplier, all parts – Got a serial number, a model code, or just a photo of a worn-out part? Our specialists cross-reference across Caterpillar, Komatsu, Hitachi, Sany, and 15+ brands to find what you need. OEM, OEM-quality, or hard-to-find older model parts – we handle the search so you don’t have to.

• Own maintenance factory and technical team – Equipped with our own maintenance factory and a team of experienced technicians, we provide global customers with one-stop solutions covering parts supply, technical support, and equipment maintenance.

• Pre-shipment verification – We never ship a main control valve blind. You receive clear photos of the actual unit before packing – you approve, we ship. When downtime costs money, we move at your speed.

• After-sales support that works – Three senior technicians review your case together. If it’s a quality issue – we cover it. If not – we still guide you through the fix. We don’t just sell parts; we keep you running.

Send us your CAT 345D or 349D machine serial number and a photo of the old control valve – we will confirm compatibility and provide a quote within 24 hours.