View Full Version : How do you flush your Radiator?

13-12-2012, 02:26 PM
Most motorists know it's recommended that our vehicle's oil should be changed about every 6 months or 1 Year depending on the oil type. Drivers are less educated, however, about proper intervals for their vehicle's other vital fluids. For the cooling system, antifreeze manufacturers recommend changing the coolant once a year, and some service manuals stipulate flushing and refilling the radiator every 24 months, regardless of mileage.

Antifreeze Importance
Antifreeze serves two important functions: protecting the cooling system at temperature extremes and inhibiting rust and corrosion in the system. Many antifreezes also have additives that help lubricate the water pump and thermostat, so coolant has multiple advantages over plain water.

Glycol Styles
Antifreeze's active ingredient is glycol. "Standard" coolants contain ethylene glycol (EG), which is toxic to people, pets, wildlife and groundwater. In recent years, less-toxic antifreezes containing propylene glycol have become available. These products advertise comparable cooling qualities to EG antifreezes but with less environmental impact. Either way, always clean up any coolant spills/radiator boil-overs promptly.

Draining & Flushing
Rust and sediment can accumulate in the cooling system. Flushing the radiator helps keep the cooling system clean. Begin by parking the car away from kids, pets and storm drains. Elevating the car on ramps can make the job easier.

With the ignition off, engine cool, car in Park and emergency brake set, remove the radiator cap. Place a bucket or pan (minimum 2-gallon capacity) under the radiator drain plug and open it. Close the plug once the coolant flow ends. For more thorough draining, remove the plug(s) in the engine block (if so equipped) to release the coolant that remains in the engine.

If the old coolant appears rusty or contaminated, flush the system with a radiator-cleaning product to further remove sediment. With all drain plugs closed, fill the radiator with a flush/cleaner product and plain water. Then run the vehicle with the heater on high for as long as the flush product's instructions specify. Once the engine cools, drain the flushing solution, refill the radiator with plain water, and repeat the sequence following the flush's instructions.

Consult your vehicle's owner's manual and the antifreeze bottle for proper coolant-to-water ratio, which can vary between 40% and 70% antifreeze based on vehicle and climate. Fill the radiator appropriately then fill the overflow reservoir to the appropriate level with a 50/50 mix. Clean up any spills immediately. Close the cap(s) and run the vehicle up to operating temperature with the heater on high to circulate the coolant throughout the system. Once the engine cools, check for leaks. After a few days of driving, double-check the coolant mixture with a hydrometer or test strips (both of which are available inexpensively from the parts store) and adjust the concentration as necessary.

Various chemical additives are formulated to improve cooling-system performance while you drive. Rust inhibitors are designed to reduce oxidation and neutralize acids; many also include lubricants for the water pump and thermostat. Other chemicals improve the coolant's heat-dissipation properties and claim up to a 20-degree F reduction in operating temperature.

Flushing your car's cooling system isn't the most glamorous way to spend a Saturday morning. But just as your refrigerator's coils need periodic vacuuming for proper operation, keeping the car's cooling system clean is cheaper and easier than the consequences of ignoring it. :grin:

Source: wiki.answers.com

14-12-2012, 05:42 PM
Experts/Gurus are welcome to add their own practical experiences/observations on flushing the radiator! :o

17-09-2013, 06:17 PM

I will be going to a local workshop on saturday for some paint removal.
Was wanting to getting the radiator flushed.
Any products members would like to recommend.

18-09-2013, 02:26 AM
i have used OWS Radiator Flush. its effective. Kindly check on Snapdeal, it is available

17-11-2013, 06:42 PM
I have not flushed the radiator but changed the whole coolant at the time of AC coil cleaning. This time want to flush the radiator. Is it recommended to change the thermostat valve at the time of flush. Also I am unable to find just the valve which costs ~ 500rs. instead I am being offered is the whole thermostat assembly which costs 4k. Where should I find the valve? 99rpm dosent have it.

18-11-2013, 09:31 AM
Can i say something very radical and willing to experiment. It might solve all potential over heating issues and dissolves rust in the entire cooling system. There is a salt available named "EDTA" tetra sodium version. Mixed with 8~10 % of water makes excellent chelating agent. Which dissolves rust and other blocks untimately form a brown liquid which is nothing but removed rust and other salts from the system. I am yet to try this in my car. It takes 24 to 48 hrs to work. It wont work with antifreeze so one must remove and pass water few times in the cooling system. Its non corrosive to aluminium so its kinda safe. It contains no acid. The side effect could be if the block is leaky it will make it worse as it removes rust from the block potential head gasket failure.
How I came to know about EDTA? I was exploring options to remove sulphide crystals from our home ups battery. It served us 2 years and gave pretty big back up time. It served us 24 hrs power outage when used diligently. Last month I noticed with similar usage ups shut down in 12 hrs. 1/2 spoon of edta per cell removed all sulphides from the plates and gave decent backup. Later I came to know its a chelating agent (Dissolves rust) so i experimented by dipping some rusted tools for 12 hrs. It came of shiny white metal and water turns dark brown. ok enough of gyan :gbeer

13-01-2014, 04:31 PM
As I mentioned in my earlier post, I have added EDTA salt in the cooling system. The system was flushed several times with corporation water and it came brown. All I can say now earlier temp gauge reaches 3/4th mark with AC after 24hrs in the salt treatment the needle was just below 1/2mark. This experiment needs a dedicated thread and I will start soon.

14-11-2014, 04:22 PM
Can we have pictures of the entire operation please?