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  • Radiator hoses manage the flow of coolant fluid in the vehicle’s cooling system.
  • Symptoms of a bad radiator hose include broken radiator hose clamps, coolant crust near the hose, coolant fluid leaks, low coolant levels, engine overheating, and a swollen or damaged radiator hose.
  • You should replace bad radiator hoses as soon as possible.

Radiator hoses play a key role in managing coolant fluid flow in your vehicle’s cooling system. Every vehicle typically has two types of radiator hoses: an upper and lower hose.

Typically,  the upper radiator hose is connected to the engine’s thermostat housing and the lower radiator hose is attached to the engine’s water pump, which suctions fluid. Both hoses also connect to the radiator at the other end.

Some radiator hoses may have a molded “T” connection with hoses leading from a radiator hose to other connections. There are also “modular” coolant and radiator hoses.

All coolant hoses need to be in good condition for the cooling system to operate properly. Unfortunately, they’re prone to wear because of constant exposure to high and low temperatures.

How to Tell If Your Radiator Hose Is Bad

A bad radiator hose may appear brittle and worn, making it easy to spot during a regular inspection. However, because the hose is hidden under your hood, you may not notice that it’s already damaged. Here are some signs of a bad radiator hose that you should look out for:

installing radiator hose
A bad radiator hose may appear brittle and worn, making it easy to spot during a regular inspection.

Coolant Fluid Leaks

If your car has a bad radiator hose, it’s likely to develop coolant fluid leaks. If a leak develops, you may immediately notice a sweet-smelling fluid dripping from underneath your car. It may appear green, yellow, purple, or blue in color, depending on the vehicle. Note, however, that there are many places from which coolant can leak – it’s not always the radiator hose.

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Other cooling system problems, such as a faulty radiator, a faulty water pump, or a cracked plastic manifold, hose fitting, or thermostat housing can also cause coolant fluid leaks.

Consult a mechanic to determine where the leak is coming from and what’s causing it. If it’s due to a bad radiator hose, you’ll need a radiator hose replacement.

Low Coolant Levels

Car owners should check vehicle fluids regularly. If your vehicle is low on coolant, it may be a sign that a radiator hose in your vehicle has become faulty. 

Coolant or antifreeze for car being poured
Car owners should check vehicle fluids regularly.

Low coolant levels, which typically trigger your low coolant light, are one of the most common signs of a bad radiator hose. Keep track of the coolant level in the reservoir. Don’t neglect this because over a long period of time, some coolant will be lost.

If it regularly goes low and has to be topped off with the 50/50 mix of the proper coolant and distilled water, it may mean that your vehicle is losing coolant fluid, possibly at your radiator hose. But usually a radiator hose leak will be fairly easy to spot.

That being said, rubber hoses allow molecular coolant transfer over long periods of time. Silicone hose is even worse than conventional rubber.

If you encounter a low coolant light, it’s best to pull over and inspect your vehicle before heading to your destination. NOTE: Do not open the fill cap on a hot cooling system to avoid serious injury.

Also, driving your vehicle with low to empty coolant fluid can lead to overheating, which can result in costly engine damage.

Coolant Crust Formation Near Radiator Hose

A seeping radiator hose can lead to coolant crust buildup at the location where the hose meets the radiator or engine.

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Failed Radiator Hose Clamps

Worm-type clamps can fail and spring type clamps can break and cause leaks at radiator hose connections.

Worm type clamp close look
Worm-type clamp that’s slightly too short. | Image source: Richard McCuistian

Swollen or Spongy Radiator Hose

Car owners should routinely check under the hood and inspect for faulty parts. If you look at your radiator hose and it’s swollen or spongy, it may be time for replacement. A swollen or spongy radiator hose may burst while driving, so it’s best to check the hoses routinely to avoid any mishaps.

Any engine or transmission oil leak near enough to wet the hose with oil will begin to degrade the rubber to the point that it begins to swell. This is also true with heater hoses.

Broken or Worn Radiator Hose

Your radiator hose is always in contact with heat and coolant fluid. The changing temperatures can cause your radiator hose to wear and break. It may develop holes, cracks, and even become brittle. If it’s in bad condition, it won’t be good for your engine. If you look under your hood and find that your radiator hose is too broken or worn to function, schedule a radiator hose replacement immediately.

Toyota Camry upper radiator hose
This Toyota Camry upper radiator hose gave way in a sudden and catastrophic fashion, even though a cursory inspection didn’t indicate that the hose had become so weak as to fail this completely. This hose failed from the inside out, but usually you can squeeze the hose on a fully cooled engine and it should be soft and pliable. | Image source: Richard McCuistian

Engine Overheats

If your cooling system isn’t properly expelling heat, your engine may overheat. Faulty cooling system parts, such as a bad radiator hose, may result in coolant leaks and overheating. A quick consultation with your mechanic can help you figure out if a leaking radiator hose is causing your engine to overheat and whether or not you need a radiator hose replacement.

What to Do if You Have a Bad Radiator Hose

Radiator hose problems can put you in troublesome situations. You should act as soon as you notice any symptoms, so that you don’t have to deal with radiator hose failure while driving. If you notice any coolant fluid leaks, take your vehicle to your mechanic straight away. Keep in mind that other parts may also cause cooling system problems, so don’t hesitate to ask your mechanic for an exact diagnosis.

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radiator repair
Radiator hose problems can put you in troublesome situations.

Having your radiator hose fail while driving may be complicated. If it happens, pull over, turn off your engine, and get your car towed to a safe location. Avoid opening your radiator cap while checking under the hood, so that you don’t burn yourself. You can get your radiator hose replaced later, once the engine has cooled down.

If you notice that your radiator hose is broken while your car is parked, you can easily take your vehicle to a mechanic for a radiator hose replacement. However, if you’re confident in your DIY skills, you can also try doing it yourself by checking out this radiator hose replacement guide.

Get a Long-Lasting Replacement Radiator Hose That Fits Your Vehicle

A damaged or worn-out radiator hose can leak coolant fluid, depleting the available coolant.

Without a steady supply of sufficient cooling fluid, the engine might run dangerously hot, which can lead to more problems. You must immediately replace a bad radiator hose, which can help you with. makes it easy to shop for a replacement radiator hose. Our website is highly accessible, and the built-in vehicle selector lets you pull up the most suitable product for your vehicle and budget. We source our parts from trusted manufacturers, so you can rest assured that you’re getting high-quality parts at the best prices. Enjoy a secure checkout process and fast shipping from our strategically located distribution centers.

The radiator hose is an indispensable part of the engine cooling system, so don’t hesitate to get a replacement for the part if it fails. Check out our selection of radiator hoses and shop now at

About The Authors
Richard McCuistian, ASE Certified Master Automobile Technician
Reviewed By Richard McCuistian, ASE Certified Master Automobile Technician

Technical Reviewer at

Richard McCuistian has worked for nearly 50 years in the automotive field as a professional technician, an instructor, and a freelance automotive writer for Motor Age, ACtion magazine, Power Stroke Registry, and others. Richard is ASE certified for more than 30 years in 10 categories, including L1 Advanced Engine Performance and Light Vehicle Diesel.

CarParts Research Team
Written By Research Team

Automotive and Tech Writers

The Research Team is composed of experienced automotive and tech writers working with (ASE)-certified automobile technicians and automotive journalists to bring up-to-date, helpful information to car owners in the US. Guided by's thorough editorial process, our team strives to produce guides and resources DIYers and casual car owners can trust.

Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.

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mark clark

side effects on a collasped radiator hose will it cause skipping

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