How To Open Vrod Radiator Housing

The thermostat is a valve that remains closed until the engine reaches operating temperature. The thermostat opens allowing engine coolant to flow out of the engine to the radiator when the coofant temperature exceeds 85° C (185° F). The thermostat is fully open at 100° C (212° F).



Do not remove the pressure filler cap when the engine is hot. The cooling system is under pressure and hot coolant and steam may escape causing severe burns. Allow engine to coot before servicing the cooling system.

1. Allow cooling system and engine to cool.

2. Remove right side cover and maxi-fuse. 3- Open seat and remove pressure cap.

4. Remove left side radiator cover. Remove radiator drain plug and drain engine coolant into suitable container.

5. Replace radiator drain plug and tighten to 9-11 Nm (80-97 in-lbs) and replace radiator cover.

6. Remove air fitter cover, air filter top, air filter, breather hose, velocity stacks, and air filter bottom. See 1.4 AIR-BOX AND AIR FILTER.

7. Remove pipe damp and p-clamp from coolant pipes.

8. Loosen lower clamp on hose to engine coolant pipe. Pull coolant outlet pipe and hose up.

9. Loosen and remove fasteners and lock washers holding housing to engine case. Pull thermostat housing off engine.

10. See Figure 6-10. Disconnect coolant temperature sensor (1) from wiring harness.


See Figure 6-f 0. The sensor (1} for the engine coofant temperature is threaded into the engine side of the thermostat housing. When illuminated red, the engine coolant temperature indicator tamp on the instrument duster indicates that the coofant temperature has exceeded 112.7 C (235 F).

11. Pull thermostat tubes (4) and o-rings (3) out of engine.

12. See Figure 6-11. To remove thermostat from housing, engage tabs on thermostat with slots of THERMOSTAT REMOVAL IDOL (Part No. HD-45307).

13. Press on end of tool to compress thermostat spring while turning toot 90° counterclockwise (COW). Remove thermostat.

Figure 6-10. Thermostat and Housing

1. To remove - counterclockwise (CCW)

2. To install - clockwise

3. Thermostat removal tool (HD-45307)

Figure 6-11. Thermostat Removal Tool




Thermostat removal tool

1. See Figure 6-11. To install new thermostat into housing, engage slots of THERMOSTAT REMOVAL TOOL (HD-45307) into tabs of thermostat while compressing thermostat spring. Turn tool 90° clockwise (CW) to lock thermostat into housing.


New components can be lubricated with engine coolant to ease assembly.

2. See Figure 6-10. With new o-rings (3) on thermostat tubes (4), push tubes into engine case.

3. Connect engine coolant temperature sensor (1) to wiring harness.

4. Be sure lower clamp is in place on hose to engine coolant pipe.

5. Orient new thermostat housing gasket (5) to mating surface on engine case.

6. Push housing pipe into pipe hose and over thermostat tubes (4). Fit housing (2) to engine case.

7. Thread in housing fasteners and tighten to 9.7 Nm (85 in-lbs).

8. With lower hose clamp in correct orientation, tighten clamp to 3-4 Nm (27-35 in-lbs).

9. Install pipe clamp and p-clamp. Tighten fasteners to 6-10 Nm (53-88 ft-lbs).

10. Install air filter bottom, velocity stacks, o-rings and breather hose. See 1.4 AIRBOX AND AIR FILTER.

11. Loosen air bleed plug. Remove pressure cap and fill with GENUINE HARLEY-DAVIDSON EXTENDED LIFE ANTIFREEZE & COOLANT through filler neck.

12. Tighten air bleed plug to 9-11 Nm (80-97 in-lbs) and replace pressure cap.

13. Replace air filter, air filter top and airbox cover.

14. Replace maxi-fuse and side cover.

15. Rinse the motorcycle with water to remove any spilled coolant.

16. After running engine, check coolant level in overflow bottle with coolant cold and motorcycle on jiffy stand. If level is below COLD FULL line, remove cap from overflow bottle and add antifreeze until fluid level reaches COLD FULL line.

17. Continue to run engine, check level, and add antifreeze until coolant level remains at COLD FULL line with the motorcycle on the jiffy stand.

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  • Nina
    How to open vrod radiator housing?
    3 years ago

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