Skip the auto shop - Our mechanics make house calls
  1. Home
  2. Articles
  3. How to Change a Radiator Valve

How to Change a Radiator Valve


The thermostat is a valve that controls the flow of coolant in the cooling system of the vehicle. It is a simple valve that, once the temperature of the coolant gets hot enough, opens and allows the coolant to flow through the radiator and cool off the engine.

Part 1 of 1: Changing the radiator valve

Materials Needed

  • Replacement housing assembly (if needed for your vehicle)
  • Thermostat

location of thermostat

Step 1: Locate the thermostat. Usually the thermostat is located towards the top front of the engine, but it varies by engine design.

The easiest way is to follow the upper radiator hose as it comes out of the radiator and connects to the engine; that is usually where the thermostat housing is located.

radiator drain plug

Step 2: Drain the coolant. If it is feasible to remove the thermostat housing, then you can proceed to drain the coolant; otherwise it is better to get the job done by an experienced mechanic.

demonstrating how to remove the radiator hose

Step 3: Disconnect the radiator hose. Once the coolant is drained, disconnect the upper radiator hose from the thermostat housing and remove it.

in the process of removing the thermostat

Step 4: Remove the thermostat. Remove the thermostat from the housing, and clean the housing assembly so it can be reused.

  • Note: In some cases the thermostat and the assembly are one unit and have to be replaced together. Be sure that the old gasket is completely removed so as not to cause a bad sealing surface.

The gasket can be either a rubber ring that goes around the thermostat or made of heavy gasket paper. Sometimes RTV silicone is used. In all cases the sealing surfaces must be clean to prevent leaks.

Step 5: Reinstall the radiator hose and refill the system. Once the thermostat housing is installed, reinstall the upper radiator hose and refill the cooling system.

Step 6: Test the system. After the system is refilled, test the operation of the cooling system by letting the car warm up and making sure that the cooling fan engages once the temperature gauge gets high enough.

Also test that there is enough heat coming through the heating vents.

If you would like a professional technician, such as one from YourMechanic, to replace your radiator valve for you, one of our mobile mechanics can work on your car at your home or office.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.


More related articles

How Long Does a Throttle Return Spring Last?
Not all vehicles on the road feature an electronic throttle control (ETC), which is also called drive-by-wire. For vehicles that don't offer this system, they have a throttle cable instead that...
Insurance Requirements for Car Registration in Kentucky
The Kentucky Transportation Cabinet requires that all drivers in Kentucky carry liability automotive insurance, or “financial responsibility” in order to operate a vehicle legally and maintain vehicle...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...

Related questions

Q: I have an engine code on a 2009 Lincoln Town Car that indicates a bad thermostat sensor or thermostat. Is this time critical to ge

If the engine does not get to operating temperature in a certain amount of time the computer will set a code after two complete drive cycles doing the same thing. This is an indication that the thermostat is stuck partly...

Q: Q: Car keeps overheating

This can be caused by a number of things such as low coolant levels, a faulty thermostat, a clogged radiator or a failing coolant fan switch. As you may know the coolant fan switch helps to maintain the proper coolant...

Q: After multiple replacement parts, car won't start - 1994 Acura Vigor

There may be an engine position sensor that has failed like a crankshaft position sensor or a cam position sensor inside the distributor. If the computer cannot tell where the engine is in its rotation or how fast its spinning,...