0 - 2 LUBRICATION & MAINTENANCE VA FLUID TYPES (Continued) engine to overheat because the specific heat of anti- freeze is lower than that of water. Use of 100 percent ethylene-glycol will cause for- mation of additive deposits in the system, as the cor- rosion inhibitive additives in ethylene-glycol require the presence of water to dissolve. The deposits act as insulation, causing temperatures to rise. The increased temperature can result in engine detona- tion. In addition, 100 percent ethylene-glycol freezes at -22° C (-8° F ). CAUTION: Use of Propylene-Glycol based coolants is not recommended, as they provide less freeze protection and less corrosion protection.
The cooling system is designed around the coolant. The coolant must accept heat from engine metal, in the cylinder head area near the exhaust valves and engine block. Then coolant carries the heat to the radiator where the tube/fin radiator can transfer the heat to the air. The use of aluminum cylinder blocks, cylinder heads, and water pumps requires special corrosion protection. Mopar t Antifreeze/Coolant, 5 Year/100,000 Mile Formula (MS-9769), or the equiva- lent ethylene-glycol base coolant with organic corro- sion inhibitors (called HOAT, for Hybrid Organic Additive Technology) is recommended.
This coolant offers the best engine cooling without corrosion when mixed with 50% ethylene-glycol and 50% distilled water to obtain a freeze point of -37°C (-34°F). If it loses color or becomes contaminated, drain, flush, and replace with fresh properly mixed coolant solu- tion. PROPYLENE-GLYCOL MIXTURES It’s overall effective temperature range is smaller than that of ethylene-glycol. The freeze point of 50/50 propylene-glycol and water is -32° C (-26° F), 10° C higher than ethylene-glycol’s freeze point. The boiling point (protection against summer boil-over) of propy- lene-glycol is 125° C (257° F ) at 96.5 kPa (14 psi), compared to 128° C (263° F) for ethylene-glycol.
Pro- pylene glycol also has slightly poorer heat transfer characteristics than ethylene glycol. This can increase cylinder head temperatures under certain conditions. Propylene-glycol/ethylene-glycol mixtures can cause the destabilization of various corrosion inhibitors, causing damage to the various cooling system compo- nents. Also, once ethylene-glycol and propylene-glycol based coolants are mixed in the vehicle, conventional methods of determining freeze point will not be accu- rate. Both the refractive index and specific gravity differ between ethylene glycol and propylene glycol. CAUTION:
Mopar T Antifreeze/Coolant, 5 Year/100,000 Mile Formula (MS-9769) may not be mixed with any other type of antifreeze. Mixing of coolants other than specified (non-HOAT), may result in engine damage that may not be covered under the new vehicle warranty, and decreased cor- rosion protection. DESCRIPTION - HOAT COOLANT COOLANT PERFORMANCE The required ethylene-glycol (antifreeze) and water mixture depends upon climate and vehicle operating conditions. The coolant performance of various mix- tures follows: Pure Water- Water can absorb more heat than a mixture of water and ethylene-glycol. This is for pur- pose of heat transfer only.
Water also freezes at a higher temperature and allows corrosion. 100 percent Ethylene-Glycol -The corrosion inhibiting additives in ethylene-glycol need the pres- ence of water to dissolve. Without water, additives form deposits in system. These act as insulation causing temperature to rise. The increased tempera- ture can result in engine detonation. In addition, 100 percent ethylene-glycol freezes at -22°C (-8°F). 50/50 Ethylene-Glycol and Water -Is the recom- mended mixture, it provides protection against freez- ing to -37°C (-34°F). The antifreeze concentration must always be a minimum of 44 percent, year- round in all climates.
If percentage is lower, engine parts may be eroded by cavitation. Maximum protec- tion against freezing is provided with a 68 percent antifreeze concentration, which prevents freezing WARNING: ANTIFREEZE IS AN ETHYLENE-GLYCOL BASE COOLANT AND IS HARMFUL IF SWAL- LOWED OR INHALED. IF SWALLOWED, DRINK TWO GLASSES OF WATER AND INDUCE VOMIT- ING. IF INHALED, MOVE TO FRESH AIR AREA. SEEK MEDICAL ATTENTION IMMEDIATELY. DO NOT STORE IN OPEN OR UNMARKED CONTAINERS. WASH SKIN AND CLOTHING THOROUGHLY AFTER COMING IN CONTACT WITH ETHYLENE-GLYCOL. KEEP OUT OF REACH OF CHILDREN.
DISPOSE OF GLYCOL BASE COOLANT PROPERLY, CONTACT YOUR DEALER OR GOVERNMENT AGENCY FOR LOCATION OF COLLECTION CENTER IN YOUR AREA. DO NOT OPEN A COOLING SYSTEM WHEN THE ENGINE IS AT OPERATING TEMPERATURE OR HOT UNDER PRESSURE, PERSONAL INJURY CAN RESULT. AVOID RADIATOR COOLING FAN WHEN ENGINE COMPARTMENT RELATED SERVICE IS PERFORMED, PERSONAL INJURY CAN RESULT.