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Introduction

Hybrid Racing K20Z3 upper coolant neck adapter was designed for 2006-2011 8th Gen Civics or K-Swap owners who need to modify or improve the function and form of their car’s cooling system. It boasts full 6061-T6 aluminum construction, lending it a strong and lightweight design along with a clean appearance that will put your OEM coolant housing to shame. The kit’s modular design allows the user to configure it to their exact setup.

  1. Start by removing the radiator cap Never open the radiator cap if the coolant is still hot.
    • Start by removing the radiator cap

    • Never open the radiator cap if the coolant is still hot.

    • Unscrew the drain plug and drain the coolant from the engine and radiator

    • Be sure to use a coolant safe container. If you are not re-using the coolant, dispose of according to your local environmental laws.

  2. Remove the air intake system.
    • Remove the air intake system.

    • This car is equipped with the Hybrid Racing air intake. The OEM air box will require a few more steps.

  3. Remove the engine wiring from the bracket. Pull the tabs outward to slide the plastic cover away from the engine.
    • Remove the engine wiring from the bracket. Pull the tabs outward to slide the plastic cover away from the engine.

  4. Remove the wiring harness bracket from the coolant housing. Remove the wiring harness bracket from the coolant housing.
    • Remove the wiring harness bracket from the coolant housing.

  5. Remove the OEM air intake support bracket. Remove the OEM air intake support bracket.
    • Remove the OEM air intake support bracket.

  6. Remove the coolant hose that connects to the IACV. If you choose to use the IACV with the HR coolant port, you should remove both sides of this hose now.
    • Remove the coolant hose that connects to the IACV.

    • If you choose to use the IACV with the HR coolant port, you should remove both sides of this hose now.

    • Remove the upper radiator hose.

  7. On the rear of the coolant housing, remove the heater hose.
    • On the rear of the coolant housing, remove the heater hose.

  8. Remove the nut that holes the heater hose pipe in place.
    • Remove the nut that holes the heater hose pipe in place.

  9. Locate and bend the heater hose pipe tab up and away from the OEM coolant housing. This is necessary for removal, otherwise the housing will not have enough room to slide off the studs.
    • Locate and bend the heater hose pipe tab up and away from the OEM coolant housing.

    • This is necessary for removal, otherwise the housing will not have enough room to slide off the studs.

  10. Remove the two upper nuts and two lower bolts.
    • Remove the two upper nuts and two lower bolts.

    • The coolant housing should be free however you may have to wiggle it loose as it can get stuck to the gasket.

  11. Slide the coolant housing away from the engine and remove it from the engine bay.
    • Slide the coolant housing away from the engine and remove it from the engine bay.

    • You may need to hold the heater pipe out of the way.

  12. Use one of the nuts and spin it on backwards. Take another nut and thread it on, tighten them together.
    • Use one of the nuts and spin it on backwards.

    • Take another nut and thread it on, tighten them together.

    • Unscrew the inside nut and the stud should back out of the cylinder head. Do this for both upper studs.

  13. Install the gasket with the tab on the top. Take two of the included bolts and stick them through the housing.
    • Install the gasket with the tab on the top. Take two of the included bolts and stick them through the housing.

    • Check to make sure all of the fittings are tight.

  14. Install the new coolant port housing and tighten them in a crossing sequence. Install the new coolant port housing and tighten them in a crossing sequence.
    • Install the new coolant port housing and tighten them in a crossing sequence.

  15. Bend the heat hose pipe mounting tab back into place and install the factory mounting bracket. Bend the heat hose pipe mounting tab back into place and install the factory mounting bracket.
    • Bend the heat hose pipe mounting tab back into place and install the factory mounting bracket.

  16. Re-install the heater hose onto the new outlet fitting. Re-install the heater hose pipe mounting bracket.
    • Re-install the heater hose onto the new outlet fitting.

    • Re-install the heater hose pipe mounting bracket.

  17. If using the IACV, install the supplied extended coolant hose. Use the OEM clamps.
    • If using the IACV, install the supplied extended coolant hose. Use the OEM clamps.

  18. Re-install the upper coolant hose.
    • Re-install the upper coolant hose.

  19. Once all of the parts are tight, fill the system with coolant and bring the engine up to operating temperature. Check for and fix all leaks. Be sure that the car has enough coolant and monitor your temperature gauge. Once the engine warms up, the thermostat will open requiring you to add more coolant to the system.
    • Once all of the parts are tight, fill the system with coolant and bring the engine up to operating temperature. Check for and fix all leaks.

    • Be sure that the car has enough coolant and monitor your temperature gauge. Once the engine warms up, the thermostat will open requiring you to add more coolant to the system.

    • If you are having trouble getting the air out of the system, you can use the top mounted bleeder screw.

  20. You're finished!
    • You're finished!

Finish Line

One other person completed this guide.

Hybrid Racing

Member since: 04/29/2014

10,751 Reputation

62 Guides authored

3 Comments

Yes, the item is discontinued.

Hybrid Racing - Reply

Did this product get discontinued?

Alex Thompson - Reply

Excellent guide

Joseph R Msdge - Reply

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