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Coolants
Jim Halderman
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Jim Halderman
Former flat-rate technician and instructor and a business owner. Author of many automotive books and lives in Dayton, Ohio.http://jameshalderman.com
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Topics to be Discussed
Engine coolants- Purpose and function Water (1/2 of the coolant)Coolant TypesCooling system testingCooling system service
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What is Coolant?
Coolant is a mixture of: 1. Water (50%)
2. Anti-Freeze (ethylene glycol-about 93%)
3. Corrosion inhibitors (additives)
Water: 50%
Ethylene Glycol: 47%
Additives: About 3%
Coolant
Need to know
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Water
Water is the principal ingredient and:
1. Is inexpensive 2. Is a very efficient heat exchange fluid 3. Has excellent thermal conductivity 4. Has a good specific heat 5. Freezes at 32°F (0°C) 6. Boils at 212°F (100°C)The water used in coolant must be clean &
pure.
Need to know
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Good Water
The American Society for Testing and Materials (ASTM) standards for water quality include:
Chloride <40 ppm Sulfate <100
ppm Calcium <100 ppm Magnesium <100 ppm Total Hardness <170 ppm pH Range: 5.5—9.0 Iron <1 ppm
Nice to know
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Good Quality Water
Good quality water types include:
Distilled- boiling water and then cooling the steam back to water
• Deionized (Also called demineralization or purified)-Has the minerals removed such as sodium, calcium, iron, copper, chloride, and bromide
Need to know
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City Tap Water
Usually unknown quality Can have unwanted
chlorides, minerals, or salts Unknown pH
Need to know
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What to do?
Test the water at the shop and if it has high mineral content, consider:
1. Purchasing distilled or de-mineralized water
2. Installing a micro filtration system
3. Installing a reverse osmosis system
Need to know
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Burst Pressure
Water expands about 9% when it freezes, and this creates the burst pressure that can break cooling system components.
Antifreezes (freeze depressants) lower the freeze temperature.
Nice to know
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Freeze and Boil
Pure Water 50/50 Anti-Freeze/Water
70/30 Anti-Freeze/Water
Freezing Point
0° C (32° F) -37° C (-35° F) -55° C (-67° F)
Boiling Point 100° C (212° F) 106° C (223° F) 113° C (235° F)
Need to know
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Ethylene Glycol (EG)
Ethylene glycol is the base antifreeze used in every OEM factory fill. The additive package will vary.
Need to know
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Propylene Glycol (PG)
Only sold to the aftermarket
Not recommended for use by vehicle manufacturers
More expensive than EG, Increased cost is $/gallon
Still toxic but is not as sweet as EG
Need to know
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Embittered Coolant
Embittered = tastes awful
Embittering agent is required (denatonium benzoate, 30 ppm) Required in California and Oregon since 2004 but not included on the label.
Need to know
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Additives
The major additives:
1. Reduce corrosion
2. Buffer (control) pH
3. Add color (dye)
Need to know
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Need to know 16
IAT
Inorganic Additive Technology (IAT) is the traditional green coolant used in most older vehicles. This solution offers fast-acting corrosion protection, but the additives are quickly consumed, exposing the cooling system to possible corrosion problems if not changed regularly.
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IAT (Usually Green in Color)
Inorganic Additive Technology (IAT) antifreeze can contain:
Silicates (possible abrasive dropouts)
Phosphates Borates
Need to know
IAT is considered obsolete and can cause early failure of ceramic-phenolic seals used in newer water pumps.
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OAT (Usually Orange)
The downside of OAT is it is not compatible with other types of coolant (IAT and HOAT). In fact, Ford, Chrysler and others say to not use this type of coolant in their newer models.
Organic Acid Technology (OAT) is the formula found in DEX-COOL®, and is usually the antifreeze/coolant of choice for GM, VW, and many Japanese/Asian vehicles. This formula is engineered to offer long-life corrosion protection.
Need to know
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OAT-continued
NAPS=nitrates, amines, phosphate and silicate free
Nice to know
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OAT=DEX-COOL is one brand
Nice to know
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DEX-COOL Concerns
Root cause= air entering system
Check cap replace cap
Air causes ‘Brown Gunk’
Rust then causes blockages
Need to know
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Rust in Engine
DEX-COOL + Air= rust orDEX-COOL + core sand = Brown gunk
Need to know
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GM DEX-COOL Problems
Class action suit; GM may have to pay for intake gaskets on V-6s (V-8s still being determined)
Brown Gunk on radiator capNeed to know
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DEX-COOL’s Unique Formulation
DEX-COOL uses Ethylhexanoic Acid (2-EH) as a corrosive inhibitor
2-EH is prone to damage plastics like Nylon 6.6 used in intake manifold gaskets and radiators
G30 OAT and Peak Global OAT do NOT use 2-EH
Nice to know
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HOAT (Many colors)
Hybrid Organic Acid Technology (HOAT) is found in newer Ford, Chrysler and Mercedes vehicles. Said to use the very best aspects of both IAT and OAT, HOAT is a very protective, long-life coolant.
Need to know
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HOAT=Red; Pink; Yellow or Blue
Nice to know
POAT Coolant Phosphated
Organic Acid Technology (POAT)
Dark Green in color Used in Mazda-
based Fords (2008+)
same as Mazda FL-22
$34.95 per gallon
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“G” Designations
G= Glysantin –trade name of BASF. Valvoline (Zerex) in the US.
G30, G33, G34= non-silicate and phosphate free (DEX-COOL replacement)
G05 = Phosphate free-low silicates (Asian formula and Chrysler HOAT)
Nice to know
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“G” Designations-continued
G11=Blue VW used before 1997 G12=Pink/Red VW 1997+ G12=Purple VW 2003+ HOAT formulation; phosphate free
?
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“G” Designations-continued
G48=Low Silicate and Phosphate free
Blue Color NAP =nitrates, amines, phosphate
free BMW
?
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Replacement Antifreeze
The best choice is to follow the vehicle manufacturer’s recommendations.
OR, you can follow the recommendations of reliable antifreeze manufacturers (next slide).
Need to know
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ColorThe color helps us identify a coolant leak. It also helps us identify the additive package.
Should not be used as an indicator what to use-some Chrysler vehicles used HOAT coolant that was green
Need to know
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Coolant Summary Ethylene glycol - Most ethylene glycol coolant is any color and contains about 93% ethylene glycol plus water and additives.
Propylene glycol - less harmful to pets and animals because it is not sweet tasting, although it is still harmful if swallowed.
Organic acid technology (OAT) antifreeze coolant – This type is ethylene glycol based but it does not contain silicates or phosphates. It is usually orange. DEXCOOL is an OAT coolant.
Hybrid organic acid technology (HOAT) – This orange, green, red, blue or yellow
coolant is an ethylene glycol based coolant similar to the OAT- type antifreeze as it uses additives (a low amount of silicate)
VW/Audi pink - Most of these coolants are HOAT (ethylene glycol-based with some silicate and contain an organic acid) and are phosphate free.
Asian red – This coolant is ethylene glycol-based and is silicate-free, yet contains phosphate.
Mercedes and Ford yellow – This conventional ethylene glycol coolant has low amounts of silicate and no phosphates.
Mercedes Lifetime – Very expensive, can be drained, filtered and reused. Korean or European blue – This conventional ethylene glycol coolant has low amounts of
silicate and no phosphates.
Nice to know
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Passivation
Passivation= is a chemical reaction the takes place between coolant additives and the metal that it protects
Takes a few days or few weeks It creates barrier between the metal and
corrosion Each chemical package does its own passivation if you change chemical packages, passivation has
to start over It boils down to: DO NOT CHANGE PACKAGES.
Nice to know
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Depletion Rate of Additives
Need to know
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pH
Substance pH
Hydrochloric acid -1.0
Battery acid 0.5
Lemon juice 2.4
Cola 2.5
Vinegar 2.9
Orange or Apple juice 3.5
Acid Rain <5.0
Tea or healthy skin 5.5
Milk 6.5
Pure water 7.0
Healthy human saliva 6.5 – 7.4
Blood 7.34 – 7.45
Sea water 7.7 – 8.3
Hand soap 9.0 – 10.0
Household ammonia 11.5
Bleach 12.5
Household lye 13.5
Caustic Soda 13.9
pH is a measure of acidity or alkalinity of a solution. Less than 7 is considered acidic. Greater than 7 is considered alkaline.
Alkaline
Acid
Nice to know
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pH Effects
Fresh antifreeze pH= 9 and 11
Used coolant pH= 7.5 and 10
It can also increase electrolysis
( the dissimilar metals in contact with an electrolyte can produce a simple battery)
Need to know
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pH of various coolants
IAT= 9.0-10.5 new OAT= 7.5-8.5 new (G30 and G34
designation) HOAT= 7.5-8.5 new (G05,G48,G11
or G12 designation)
Need to know
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Desired pH
Need to know
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pH Tests
pH can be measure using test strips or a meter.
Fairly accurate and costs pennies/test.
Need to know
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pH Meter
This Milwaukee is probably more accurate and cost $30.00.
Need to know
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Corrosion
Corrosion is the “decomposition of metal”
(called rust or aluminum oxide, the whitish material that forms on aluminum components)
Oxide formation:
1. eats away at the parent material from the outside
2. forms an insulating barrier for heat transfer
Need to know
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Metal Corrosion
This iron tube has been ruined by rust.
Need to know
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Corrosion
aluminum oxide, often found on coolant outlet/stat cover
Need to know
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Corroded Water Pump
One of the reasons for the removal of silicates from coolantNeed to know
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Corroded pump can cause:
reduced coolant flowand an overheating
condition
Need to know
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Cavitation
Cavitation is the sudden formation and collapse of low-pressure bubbles. With gasoline engines, the pressure drop can occur at the inlet of the water pump. These bubbles produce a pitting of the solid metal .
Cavitation
Need to know
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Cavitation Damage
The very low pressure can produce gas bubbles that implode next to a metal surface. The implosion blasts particles from the surface.
Need to know
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Diesel Wet Sleeve Cavitation
The sleeve can vibrate during the combustion stroke producing the pressure drop, bubbles, and metal erosion. Heavy duty coolants contain supplemental coolant additives (SCA) to help prevent this.
Need to know
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Galvanic action
Galvanic activity does not require an outside source of voltage
The higher the conductivity of the coolant, the greater the amount of corrosion
Need to know
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Metals
Nice to know
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Bi-Metal Corrosion
Ions move from more active metals to less active metal through the coolant which acts like the electrolyte
Nice to know
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Electrolysis
Electrolysis requires the use of an outside voltage source.
•When electrical ions move from metal to the coolant, they can take metal atoms with them
• This metal transfer can eat holes in a heater core or radiator.
•Electrolysis holes will usually start from the inside and have a dark coloration. Need to know
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Testing Coolant with a Voltmeter
This test gives variable and questionable results depending on many factors
Galvanic=less than 200 mV Electrolysis= (engine running and
accessories switched on and off)=less than 300 mV. This check can locate faulty ground connections
Need to know
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Radiator Voltage
Connect the negative voltmeter lead to a good ground (this radiator has a plastic filler neck), and immerse the positive lead into the coolant. A reading of 0.300 V or greater indicates corrosion is probably occurring.
Need to know
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Coolant Condition
This “green” antifreeze has a clean, bright appearance. The other types will have a different color but should also appear clean and bright.
A muddy brown or rust-reddish color indicates that corrosion is occurring.
Need to know
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Freeze Protection, Refractometer
A few drops of coolant are placed under the sample window. The technician then holds the unit up to light and looks through the eye piece (right end).
Sample Window
Eye Piece
Need to know
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Refractometer Image
The image will show the amount of freeze protection and is read at the scale at the bottom edge of the shadow. This unit can check EG and PG antifreeze freeze protection and battery specific gravity.
Shadow
Read Here
Need to know
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Freeze Protection, Test Strips
Test strips will change color when they are dipped into the coolant, and the color change is compared to the container.
Test strips are fairly accurate, easy to use, and inexpensive.
Need to know
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Coolant Corrosion Protection
The new test strip color is compared to the color pads on the container to determine the amount of freeze protection and corrosion protection.
Need to know
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Coolant Replacement
1. 15 to 20% remains in the system after it has been drained
2. Fill system with antifreeze first and top off with water
3. Be sure to use the specified coolant
(GM warns not to reuse coolant drained from the system)
(Mercedes has a lifetime coolant, drain, filter, & reuse)
Need to know
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Coolant Replacement-#2
Check the pressure cap and radiator for faults Check all hoses and always use coolant hose
Need to know
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Universal Coolant Universal Gold =HOAT, extended life, low-
silicate, phosphate-free antifreeze/coolant.
This product meets Ford WSS M97B51-A1 and Chrysler MS 9769 and other "global antifreeze" type specifications, as well as ASTM D3306, D4985 and D6210/11
Nice to know
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Universal Coolant
• Arctic Blend
• Recycool
•Prestone Prime
coolants that have been formulated to be used in any vehicle
Nice to know
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Coolant Recovery and Storage
Some shops recycle used antifreeze
Should be stored until picked up for recycling
Notice double containers to help avoid spills
Need to know
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Flushing a Dirty System
1. Drain system 2. Fill system with clean water & chemical 3. Run system to operating temp. (Heater on) 4. Drain system & fill with clean water 5. Repeat until drain water runs clear Any remaining flush agent will upset pH. 6. Fill system with 50/50 antifreeze/water mix 7. Run system to operating temp. (Heater on) 8. Adjust coolant level
Need to know
Caution: If flushing a really dirty system, be prepared to repair some leaks.
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Flushing
Some communities permit draining into sewer. EG and PG will biodegrade. There is a problem however if coolant is spilled on open ground.
Need to know
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Be sure to clean the overflow/surge tank
It should empty if you start draining with the cap in place.
Need to know
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Mix Coolant 50/50 or use premix
?
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Coolant Exchange Machine
Most shops use machines like this.
Coolant drains have become fragile and hard to find.
Need to know
TECH TIP Check the freezing Point after
service Should be -34 degrees F (proper
50/50 mix) If higher (i.e. -20 F) this means that
there is too much water. If lower (i.e. -40 F) this means that
there is too much antifreeze
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Always check or replace the radiator pressure cap
The cap can be located on
1. the radiator
2. The coolant recovery reservoir
3. The upper radiator hose
Note the pressure.
Need to know
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Cap has two seals
What will happen if the upper seal fails? What will happen if the lower seal fails?
Upper Seal
Filler Neck
Lower Seal
To CRR
Need to know
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Never open when hot!
What can happen if the cap is removed from a hot system?
Need to know
1 psi will increase the coolant boiling point 2.7oF. A 15 lb. Cap will increase the BP 40.5oF.
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Proper Fill
All of the air must be removed from the cooling system by one of these methods:
Bleeder screw: lets air escape Air Lift: evacuates system before fill Spill-Free Funnel: Lisle #22150 Fluid Exchange: requires special
equipment
Need to know
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Bleeder Valves
Use a clear hose attached to the bleeder valve and the other end in a “suitable” container
Prevents coolant from getting on the engine and gives the technician a visual clue as to color of coolant
Need to know
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Leak Detection
A good system holds pressure
Tracer dye and some antifreezes glow under UV light
Need to know
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What should Technician's do?
Check service information for the designated coolant and replacement interval
Check the coolant appearance and level at every service
Check the pressure cap appearance at every service
Check the appearance and pH for signs that the coolant should be replaced before the regular service interval
Check Freeze Point, pH, and Galvanic/Electrolysis
Need to know
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Typical Questions/Answers
1. Are all green antifreezes the same?A. No-Chrysler used HOAT coolant that was green like IAT coolant
2. Can DEX-COOL be replaced with conventional green coolant?A. Yes, but then the coolant has be replaced every 24 months or 24,000 miles
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Questions/Answers
3. Can coolants be mixed?A. No
4. Is DEX-COOL propylene glycol ?A. No. DEX-COOL and all other coolants are ethylene glycol except one labeled propylene glycol and is never used from the factory
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Summary Not all coolants are the same Not all tap water is OK to use Premixed coolant usually produces
good results Check the coolant freezing/boiling point Check the coolant pH Always check or replace the pressure
cap, especially on DEX-COOL vehicles
