How to Fix a Radiator Hose Leak

radiator hose leakLeaks in your vehicle can be frustrating.  However, even though leaks are frustrating, the time, energy and money that has to be spent to fix the leak can be even more overwhelming.  If this is true of you, you probably have some leaks that have been going on for quite some time, and possibly some other neglected maintenance items on your vehicle.  Your vehicle is just like many things in life where taking the easy road now may result in finding yourself stuck on the hard road.  Literally.

Neglecting leaks in your vehicle’s cooling system is one of the quickest ways to cause permanent damage to your engine.  By permanent damage, we mean the really high repair bill or scrap your car kind of damage.  The temperatures in modern day engines are designed to be extremely high.  In general, the hotter the burn in your combustion chamber, the more efficient your engine will be which means better mileage and more power.  Depending on the type of engine you have in your car, the combustion gases may burn at 15000F up to 40000F so without adequate cooling, you can end up with problems very quickly.  These problems can include melted pistons, or warped or even cracked engine blocks or cylinder heads.

If you allow a leak to persist in your engine’s cooling system, you will eventually get a low coolant level in your vehicle.  Low coolant levels can lead to improper cooling simply due to the lack of cooling in your system which can lead to boiling in the engine block, and hot spots where coolant no longer reaches.  These hot spots can create extreme temperature gradients which will put an extreme amount of stress on the components in your engine as well as the gaskets and seals.

One of the most common leak points in any engine is from the hoses that connect the radiator to the engine and the engine to the heater core.  These hoses are usually made from rubber and over time can start to deteriorate even under normal operation.  You can usually tell your hoses are in need of replacement simply by looking at them.  If your cooling hoses are swollen, cracked, especially on the ends, or have bulges in them it is probably time to replace them.  Some mechanics will recommend you change your radiator hoses at certain intervals since they are so vital to your vehicle’s health.  While this is not bad advice, usually radiator hoses give ample warning before they fail by cracking, leaking or bulging.

If you have a radiator hose leak, fixing it is usually pretty simple.  Most auto parts stores carry hoses specific to your vehicle meaning they are constructed with the right length, shape and diameter to fit perfectly on your car.  Once you’ve got the new hose, you can start the replacement process by draining your vehicle’s coolant.  There should be a drain plug on the bottom of your radiator, usually on the driver’s side, or you can simply remove one end of the lower radiator hose.  If you try this, just make sure you have a large catch basin under the hose because a lot of coolant will come out very quickly.

radiator hose leakOnce the system is drained of coolant, simply remove the old hose and install the new one.  The hose may be attached with a spring clamp or band clamp.  Either way, make sure you inspect the old clamp and replace it if it is rusty or weak along with your new hose.

With your new hose installed, you should consider flushing your cooling system before adding new coolant.  If you had a hose that needed to be replaced, chances are it has left some deteriorated rubber in your cooling system.  Also, if your vehicle is old enough to need new radiator hoses, it is probably also old enough to have quite a bit of scale and corrosion built up in the cooling system.  Flushing your cooling system will help remove this debris and scale from your radiator and engine block to help bring your cooling system back up to its original flow rate and heat transfer abilities.  This will help protect your engine from hot spots and overheating.  Since you’ve already got your cooling system drained after a hose replacement, it is a great time to flush your cooling system without wasting good coolant.

The best way to flush your cooling system is to use BlueDevil Radiator Flush.  BlueDevil Radiator Flush will deep clean your cooling system without harming any of the components bringing your cooling system back to life.


You can learn more about BlueDevil Radiator Flush by visiting our information page here:

You can also purchase BlueDevil Radiator Flush from any of our partnering local auto parts stores like:

  • AutoZone
  • Advance Auto Parts
  • Bennett Auto Supply
  • CarQuest Auto parts
  • NAPA Auto Parts
  • O’Reilly Auto Parts
  • Pep Boys
  • Fast Track
  • Bumper to Bumper Auto Parts Specialists
  • S&E Quick Lube Distributer
  • DYK Automotive


Picture provided by:

radiator_hose_leak.jpg – by bushytails – Licensed By Creative Commons Via Wikimedia – Original Link
radiator_hose_clamp.jpg by Zartronix – Licensed By Creative Commons – Original Link




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3 responses to “How to Fix a Radiator Hose Leak

  1. Thanks for all the info. Single daughter just trying to make it without dad. He use to take care of all this and He passed away a year ago. Grateful for all He taught me or I wouldn’t have known to look here. Thanks guys.

  2. I have a 2000 Monte Carlo SS and I have a leak on my upper hose to for the radiator what can I use til I can afford a new hose

    1. Justin-

      Thank you for asking about your Chevy Monte Carlo. Unfortunately, we do not manufacture a product for leaking radiator hoses. Replacing the hose would be your best option.

      Thank you!


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