Description

Mitsubishi OEM Water Pipe to Thermostat O-Ring — Evo 7/9 — Part #MD030763

Firstly, Buy Mitsubishi OEM Water Pipe to Thermostat O-Ring MD030763 for Evo 7/9. The Mitsubishi OEM Water Pipe to Thermostat O-Ring MD030763 is a genuine Mitsubishi replacement sealing ring designed for the cooling-water connection between the water pipe and thermostat housing on compatible Mitsubishi Lancer Evolution models. This OEM O-ring is commonly listed for the Evolution VII and Evolution IX, where the water-pipe design uses this sealing point. Mitsubishi parts references identify MD030763 as an O-ring for the cooling-water line, while Evo-specific suppliers list it for Evo 7 and Evo 9 applications.

A small O-ring can play an important role in maintaining a reliable engine cooling system. The seal sits at the water pipe connection and helps prevent coolant from escaping between the mating components. When an older O-ring becomes hard, flattened, brittle, or damaged, replacing it with the correct OEM part can help restore the intended sealing arrangement.

For Evo owners servicing the thermostat housing, water pipe, water pump inlet, or related 4G63 cooling components, the MD030763 is a useful replacement item to have available during disassembly and reassembly.

Mitsubishi OEM Water Pipe to Thermostat O-Ring MD030763

The Mitsubishi OEM Water Pipe to Thermostat O-Ring MD030763 is designed for the factory water-pipe-to-thermostat housing connection used on applicable Evo 7 and Evo 9 cooling systems. It is a small component, but its sealing function is essential to keeping engine coolant inside the intended passage.

Firstly, a new O-ring provides a fresh sealing surface when the water pipe is removed. Secondly, genuine Mitsubishi hardware helps maintain the original dimensions and sealing design. Thirdly, replacing an old seal during cooling-system service can help reduce the risk of coolant leakage after reassembly.

The MD030763 is therefore well suited to thermostat service, cooling-system repairs, 4G63 engine maintenance, and factory-style Evo restoration projects.

Evo 7 and Evo 9 Application

MD030763 is commonly identified as the water pipe to thermostat housing O-ring for Mitsubishi Lancer Evolution VII and Evolution IX models. Evo-specific parts suppliers state that it is not used on the Evo 8 because the Evo 8 water-pipe arrangement is different.

Typical applications include:

• Mitsubishi Lancer Evolution VII
• Mitsubishi Lancer Evolution IX
• 2.0L 4G63 turbocharged engine
• CT9A platform
• Water pipe to thermostat housing connection
• Engine cooling system
• Thermostat and water-pipe assembly

Some Mitsubishi catalog references describe MD030763 more generally as an engine coolant pipe O-ring, return pipe O-ring, or O-ring for the cooling-water line.

Buy Mitsubishi OEM Water Pipe to Thermostat O-Ring MD030763 for Evo 7/9, Genuine 4G63 cooling-system seal for the thermostat housing. Shop online.

Because cooling-system components can differ between Evolution generations, it is important to match the part number to the exact vehicle configuration before ordering.

Important Evo 8 Fitment Note

The Evo 8 deserves special attention when ordering this O-ring. Although some aftermarket listings use broad “Evo 7/8/9” terminology, multiple Evo-specific sources state that MD030763 is not used on the Evo 8 water-pipe arrangement. The Evo 8 uses a different water-pipe configuration.

For that reason, this product should be marketed primarily as an Evo 7/9 water pipe to thermostat O-ring, rather than as a universal Evo 7/8/9 component.

This distinction is particularly important for customers rebuilding a 4G63 cooling system. Using the correct O-ring for the correct water-pipe design helps avoid ordering the wrong sealing component.

Genuine Mitsubishi OEM Quality

The MD030763 is a genuine Mitsubishi OEM replacement O-ring. OEM parts are useful when maintaining the original cooling-system configuration because they are specified for the intended Mitsubishi assembly rather than being a generic universal seal.

The Mitsubishi parts catalog lists MD030763 with a 15.9 mm specification and identifies it under several related names, including engine coolant pipe O-ring and cooling-water-line O-ring.

Using a correct OEM seal is especially valuable when servicing an older Evolution. After years of heat cycles, coolant exposure, and repeated maintenance, original rubber seals can lose their flexibility. Installing a fresh seal during a repair is a practical way to avoid reusing an aged component.

Key Features and Benefits

The Mitsubishi OEM Water Pipe to Thermostat O-Ring MD030763 offers several important benefits:

• Genuine Mitsubishi OEM replacement
• Mitsubishi part number MD030763
• Water pipe to thermostat housing O-ring
• Designed for the cooling-water connection
• Commonly listed for Evo 7 and Evo 9
• Suitable for the 4G63 cooling system
• Factory-style sealing design
• Helps prevent coolant leakage at the pipe connection
• Useful during thermostat housing service
• Ideal for water-pipe replacement
• Suitable for 4G63 engine maintenance and restoration
• Compact replacement component for cooling-system repairs

The Mitsubishi reference number associated with this component is 10199P in parts listings.

When Should You Replace the O-Ring?

It is good practice to inspect the O-ring whenever the related water pipe or thermostat housing is removed. An O-ring that has been compressed for many years may not seal as effectively after being disturbed.

Signs that the seal may need replacement include:

• Coolant residue around the connection
• Visible coolant leakage
• A flattened or hardened O-ring
• Cracking or deterioration
• Water-pipe removal during engine service
• Thermostat housing replacement
• Water-pipe replacement
• 4G63 engine rebuilding

Replacing a low-cost sealing component during planned maintenance can also save time compared with having to disassemble the same area again because of a coolant leak.

4G63 Cooling System Application

The Mitsubishi 4G63 turbocharged engine used in the Evolution 7 and Evolution 9 has a complex cooling system containing the thermostat housing, water pipes, water pump, coolant hoses, thermostat, and multiple sealing components.

The MD030763 works specifically at the water-pipe-to-thermostat housing connection. It should not be confused with the separate water-pump O-ring used elsewhere in the cooling system. Mitsubishi parts references distinguish MD030763 from MD030764, which is another cooling-system O-ring used across a broader range of Mitsubishi applications.

Using the correct O-ring at each location is important because different cooling-system connections can require different seal dimensions.

Ideal for Evo Maintenance and Restoration

The MD030763 is an excellent small replacement part to include when rebuilding or refreshing an Evo 7 or Evo 9 cooling system. It can be ordered alongside a thermostat, thermostat housing gasket, water pipe, water pump, coolant hoses, clamps, and other Mitsubishi Evo parts.

For customers restoring a CT9A to factory specification, using genuine Mitsubishi seals also helps maintain the original approach to the cooling-system assembly.

Whether you are performing preventative maintenance or rebuilding a 4G63 engine from the ground up, replacing old seals during disassembly is a simple step that can contribute to a cleaner and more reliable installation.

Buy Mitsubishi OEM MD030763 Online

If you need to buy Mitsubishi OEM Water Pipe to Thermostat O-Ring MD030763 for an Evo 7 or Evo 9, this genuine Mitsubishi replacement seal is designed for the applicable factory water-pipe-to-thermostat housing connection.

When shopping for Mitsubishi Evo parts online, always match the exact part number and cooling-system configuration. This is particularly important with the Evo 7, Evo 8, and Evo 9 because their water-pipe arrangements are not identical. Evo-specific parts sources identify MD030763 for Evo 7/9 and specifically note that it is not used on the Evo 8.

You can shop and order genuine Mitsubishi Evo parts from evomotorparts.com, including OEM cooling-system components, seals, thermostats, water pipes, and 4G63 engine parts for customers maintaining Evolution models around the world.

Frequently Asked Questions

What is Mitsubishi part number MD030763?

MD030763 is a genuine Mitsubishi OEM O-ring used at a cooling-water-line connection. For Evo applications, it is commonly identified as the water pipe to thermostat housing O-ring.

Does MD030763 fit the Evo 7?

Yes. Evo-specific parts suppliers list MD030763 for the Mitsubishi Lancer Evolution VII, including the early CT9A applications.

Does MD030763 fit the Evo 9?

Yes. MD030763 is commonly listed for the Mitsubishi Lancer Evolution IX water-pipe-to-thermostat housing connection.

Does MD030763 fit the Evo 8?

No, not for the standard Evo 8 water-pipe arrangement. Evo-specific suppliers state that the Evo 8 uses a different water pipe and does not use MD030763 at this location.

Is MD030763 the thermostat gasket?

No. MD030763 is an O-ring for the water pipe to thermostat housing connection. The thermostat housing-to-head gasket is a separate component.

Is MD030763 the same as MD030764?

No. MD030763 and MD030764 are different Mitsubishi cooling-system O-rings used at different locations. Mitsubishi parts references identify MD030764 as a separate, larger O-ring used across a broader range of applications.

Should I replace the O-ring when removing the water pipe?

Yes. If the water pipe is being removed, replacing the old O-ring is recommended rather than reinstalling a seal that may have become hardened or compressed with age.

Is MD030763 genuine Mitsubishi?

Yes. MD030763 is listed by Mitsubishi parts sources and Evo-specific suppliers as a genuine Mitsubishi OEM component.

What engine does this O-ring apply to?

For the Evo 7 and Evo 9 applications covered by this listing, MD030763 is associated with the 2.0L turbocharged 4G63 engine and its cooling-water system. Maintain the correct factory-style cooling-system seal on your Mitsubishi Lancer Evolution 7 or 9 with the genuine Mitsubishi OEM Water Pipe to Thermostat O-Ring MD030763, and shop evomotorparts.com for quality Mitsubishi Evo parts for your next repair, maintenance, restoration, or 4G63 engine project.

Buy Mitsubishi OEM Water Pipe to Thermostat O-Ring MD030763 for Evo 7/9. Genuine 4G63 cooling-system seal for the thermostat housing. Shop online.