1993 GMC Suburban Owner's Manual - Page 292

Thefollowingexplainsyourcoolingsystemandhowtoaddcoolantwhenit low. If youhaveaproblemwithengineoverheating,see"Engine Overheating" in theIndex. The proper coolant for your vehicle will: 8 is Givefreezingprotectiondownto Giveboilingprotectionupto Protectagainstrustandcorrosion. -34°F (-37°C). e 8 258°F (125°C). Helpkeeptheproperenginetemperature. 8 Letthewarninglightsandgagesworkastheyshould. What to use: Use amixture of clean water (preferablydistilled),andantifreezethatmeets "GM Specification6038-M,"whichwon'tdamagealuminum parts. Also use GM EngineCoolantSupplement(sealer)withacompletecoolantchange. If you ,use these,youdon'tneedtoaddanythingelse. . ... . Adding only plain water to your cooling system can be dangerous. boil beforethe Plainwater,or some otherliquidlikealcohol,can is set propercoolantmix will. Yourvehicle'scoolantwarningsystem forthepropercoolantmix.Withplainwaterorthewrongmix,your engine could get too hot but you wouldn't get the overheat warning. Yourenginecouldcatchfireandyou or otherscouldbeburned.Use If you use an improper coolant mix, your engine could owheat and be badly damaged. The repair cost wouldn't be covered by your warranty.,Too much water in the mix can freeze ,and crack the engine, radiator, heater coreandother parts. Some conditions,suchasairtrapped in thecoolingsystem,canaffectthe coolantlevel in theradiator.Checkthecoolantlevelwhentheengineiscold and follow thestepsunder"AddingCoolant" for theproperway to add coolant. If you havetoaddcoolantmorethanfourtimesayear,haveyourdealer check your cooling system. 6-26