35B94-00201 Oil Pump Repair Kit Seal – For Mitsubishi Marine S12H Diesel Engine & Generator
For marine operators and power plant engineers running the Mitsubishi S12H diesel engine, maintaining stable oil pressure is just as critical as fuel delivery. The engine’s lubrication system relies on a precision oil pump – and over time, heat, pressure, and fuel dilution take their toll on the seals and O‑rings. The 35B94-00201 Oil Pump Repair Kit Seal is a complete, OEM‑grade gasket and seal set engineered specifically to restore your S12H oil pump to factory‑fresh condition, eliminating leaks and ensuring consistent oil flow to all critical bearings.
Whether you are performing a scheduled overhaul or addressing an unexpected oil leak, this repair kit provides every sealing component you need – from shaft oil seals to housing O‑rings – in one convenient package. In this guide, we cover the kit’s contents, compatible engine models, common failure signs, installation best practices, and why Rsolid Engine Parts is the global supplier you can trust.
1. Structural Features & Advantages of the 35B94‑00201 Repair Kit
The 35B94‑00201 is not just a collection of rubber rings – it is a precisely engineered sealing solution designed to withstand the harsh marine environment. Here is what makes this kit stand out:
Complete all‑in‑one kit – Includes every seal, O‑ring, gasket, and oil seal required for a full oil pump overhaul. No need to source individual parts or worry about missing components.
Premium FKM (Viton®) and NBR materials – Selected for exceptional resistance to high temperatures (up to 150°C continuous), engine oil, diesel fuel dilution, and the corrosive effects of saltwater atmosphere in marine engine rooms.
Precision‑molded O‑rings – Manufactured to exact Mitsubishi dimensional specifications, ensuring a perfect compression fit that prevents internal oil bypass and maintains pump volumetric efficiency.
High‑quality shaft oil seals – Feature a dual‑lip design with a garter spring, providing a positive seal against the pump drive shaft and preventing oil leakage into the timing gear case.
Reinforced paper / composite gaskets – Resistant to oil soak and compression set, ensuring a leak‑free mating surface between pump halves and the engine block.
Factory‑matched tolerances – Every seal is tested for hardness (shore A) and tensile strength to match original Mitsubishi service parts, guaranteeing longevity equal to or exceeding the factory original.
Operational advantages for end‑users:
Eliminates external oil leaks – Stops unsightly and hazardous oil drips in the engine room or generator enclosure.
Restores oil pressure – Prevents internal leakage within the pump, ensuring full flow to main bearings, camshaft, and turbochargers.
Prevents catastrophic engine failure – By maintaining proper lubrication, it protects against bearing seizure and crankshaft damage.
Cost‑effective alternative – A full pump replacement can be 5‑10 times more expensive; this kit restores performance at a fraction of the cost.
DIY‑friendly – Designed for straightforward installation during a routine pump removal and overhaul.
2. Compatible Engine Models & Typical Applications
The 35B94-00201 repair kit is specifically designed for the Mitsubishi S12H series marine and generator engines. The S12H is a 12‑cylinder, V‑configuration, 4‑stroke diesel renowned for its reliability in continuous heavy‑duty service.
| Engine Model | Typical Applications |
|---|
| Mitsubishi S12H (all variants including PTA, MPTA, YPTA) | Main propulsion for medium‑sized fishing vessels, coasters, harbour tugs |
| Mitsubishi S12H‑generator sets | Prime and standby power generation on offshore platforms and land‑based plants |
| Applicable System | Engine lubricating oil pump (internal gear or rotor type) |
Critical cross‑reference: The 35B94‑00201 is the official service kit part number for S12H oil pump overhauls. It may also be listed under alternative numbers such as 35B94‑00200 or 35B94‑00202 in some catalogues – always verify the pump casting number on your existing unit to confirm compatibility.
3. Common Failure Modes & Installation/Replacement Recommendations
Typical Warning Signs That Your Oil Pump Seals Are Failing
Visible oil leaks – Puddles or drips under the pump mounting flange or around the drive shaft area.
Dropping oil pressure – Especially noticeable at idle or low RPM, indicating internal bypass past worn O‑rings.
Oil aeration / foaming – Caused by air being sucked in through a failed inlet O‑ring, leading to noisy hydraulic lifters or bearing knock.
Increased oil consumption – Oil leaking externally or being drawn into the combustion chamber via the timing case (in extreme cases).
Contaminated engine oil – The presence of coolant or fuel in the oil can accelerate seal degradation – if seals are failing, check for other issues simultaneously.
Professional Installation Best Practices
Drain oil and remove pump – Safely drain the engine oil and remove the oil pump from the engine block. Clean the pump exterior thoroughly to prevent debris ingress during disassembly.
Complete disassembly – Carefully disassemble the pump (inner rotor, outer rotor / gears, drive shaft, and housing). Note the orientation of all components for reassembly.
Thorough cleaning – Use a suitable solvent and a lint‑free cloth to clean all metal mating surfaces. Pay special attention to seal grooves – remove old sealant and carbon deposits.
Lubricate new seals – Apply a thin film of clean engine oil to all new O‑rings and shaft seals before installation. This prevents pinching and ensures a proper initial seal. Never use grease or silicone – it can block oil galleries.
Install shaft oil seals carefully – Use a seal driver or a suitable socket to press the new shaft seal evenly into its bore. Ensure the sealing lip faces the correct direction (towards the oil side, typically).
Assemble with correct torque – Reassemble the pump housing halves and tighten bolts to the manufacturer’s specified torque (typically 25 – 35 N·m for M8 bolts – verify with your engine manual). Over‑tightening can distort the housing and cause rotor binding.
Prime the pump – Before reinstalling, pack the pump with clean engine oil or petroleum jelly to ensure immediate suction on startup (prevents dry‑running).
Reinstall and test – Mount the pump back on the engine, refill with the correct grade of oil, and start the engine. Check for leaks and verify oil pressure at idle and rated speed.
4. Why Rsolid Engine Parts Is Your Preferred Supplier
Rsolid Engine Parts has supplied heavy‑duty diesel components to the marine and power generation sectors for over 15 years. Here is why the 35B94‑00201 from Rsolid is the smart choice:
OEM‑equivalent quality – Sourced from ISO 9001 certified manufacturers using genuine material specifications (ASTM D2000 for rubber compounds). No cheap substitutes.
Complete kit assurance – We verify every kit against the Mitsubishi parts list before dispatch – so you never receive a kit missing a critical seal.
100% fresh stock – All seals are stored in climate‑controlled warehouses to prevent premature ageing or hardening.
Global logistics – Strategically stocked in Asia, Europe, and the USA – typical delivery 3‑7 working days worldwide.
Competitive pricing – Volume discounts for workshops, fleet operators, and distributors. Ask about our combined shipping rates.
Free technical support – Our engineers provide illustrated installation guides, torque specifications, and troubleshooting advice via WhatsApp or email.
Solid warranty – 12 months against material defects and premature failure under normal operating conditions.
Contact Rsolid Engine Parts Today
📧 Email: amy@rinjector.com
📱 WhatsApp: +86 15975376778
Whether you need a single 35B94‑00201 kit for a planned overhaul or multiple kits for a fleet of S12H engines, Amy and her team will respond with a detailed quotation, stock confirmation, and shipping options within 2 hours. We also supply complementary parts – gasket sets, bearing shells, and oil filters – for complete engine rebuilds.
Choose the 35B94‑00201 oil pump repair kit from Rsolid – keep your Mitsubishi S12H lubricated, leak‑free, and ready for the next voyage or power demand.
