Skip the auto shop - Our mechanics make house calls

What Is the Difference Between the Upper and Lower Radiator Hose?

radiator hose

Your radiator is an essential part of your automobile. It does more than just hold the bulk of the car’s coolant, though. It’s actually responsible for removing excess heat from the coolant before it is sent back to the engine once more to start the process over again.

How a radiator works

Your radiator is made of both metal and plastic. Metal fins allow the heat absorbed by the coolant to radiate outward, where it is wicked away by moving air. Air flows over the radiator from two sources – the cooling fan (or fans) blow air over the radiator when it reaches a certain temperature. Air also flows over the radiator when you’re traveling down the road.

Coolant is transported into and out of the radiator by hoses. There’s an upper and lower radiator hose. While they both transport coolant, they’re very different. If you were to place them side by side, you’d find that they were different lengths and different shapes. They also do different jobs. The upper radiator hose is where the hot coolant enters the radiator from the engine. It cycles through the radiator, cooling as it goes. When it reaches the bottom, it moves out of the radiator through the lower hose and back into the engine to start the cycle once more.

The upper and lower radiator hoses on your engine are not interchangeable. What’s more, at least one of the two is probably a molded hose, rather than just a length of standard rubber hose. Molded hoses are specially designed for specific applications and are not interchangeable with other hoses, even other molded hoses on different vehicles.

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

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

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.


Post a question and get free advice from our certified mechanics.


More related articles

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...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
The Traveler’s Guide to Driving in Malaysia
CraigBurrows / Malaysia is a popular destination for many tourists today. The country has amazing sights and attractions that you will want to explore....

Related questions

Q: Power steering return hose leaks.

Check the clamps and make sure they are tight. If not, the line may have to be replaced. A Fluid leak like this can come from several different places. The hose can experience high pressure, especially where they meet with...

Q: Why Do Hoses Collapse?

Hoses undergo a variety of system changes during normal engine operation. When the engine is completely warmed up, pressure inside the cooling increases to around 18 - 20 psi. This causes the hoses to expand. One hose in particular has...

Q: Coolant leak codes

The code P2187 indicates a lean running situation at idle. More parameters will need to be checked to get to the bottom of this issue. Sometimes false reading from a malfunctioning mass air flow sensor may mess with the vehicle's...