I want to test the freeze point of the coolant in my 93 Dodge Spirit so I went to Canadian Tire and looked at the antifreeze testers the had there. The house brand one was $4.99, the Prestone branded one was %8.99. I got a bit confused looking at the instructions on the back of those testers, the Canadian Tire branded one says to run the engine for 5-10 minutes then test the coolant from the overflow bottle. The Prestone branded one says to let the engine cool, then test the coolant. Why would one have you run the engine first, and one not?
Antifreeze tester ?'s
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Those little floaty ball things are pretty inaccurate.
They just measure specific gravity, and poorly.
You should follow the directions to a T; I would get the test-when-cold one.
I took several samples of my coolant then added different amounts of "too much" water, so I had a beaker at 25%, 12%, etc then tested them both by freezing and with the floaty ball test. Inconclusive in every possible way!
They just measure specific gravity, and poorly.
You should follow the directions to a T; I would get the test-when-cold one.
I took several samples of my coolant then added different amounts of "too much" water, so I had a beaker at 25%, 12%, etc then tested them both by freezing and with the floaty ball test. Inconclusive in every possible way!
WHen you have two liquids that are miscible, they depress each others freezing points. There is no sharp line of total freeze, until you get to the exact eutectic composition. You will start to see ice crystals at any other concentration that increase as the temperature falls to the eutectic freezing point. You need to do a time temperature graph to see this accurately.
55
Why test for the freezing point? If you put in the correct mixture of antifreeze and water the last time you flushed the system, it will still be there. If you added water to make up for a leak, yes, the freezing point will be higher.
If your antifreeze is old, then the corrosion inhibitors are depleted and you need to flush and refill the system. The easiest test for active corrosion inhibitors is with a digital volt meter. Put one probe in the cold coolant in the radiator neck & don't touch metal. Put the other probe on the battery negative post. If you read 0.1 to 0.3 volts DC, the corrosion inhibitors are still good. If you read 0.5 VDC or higher, your engine is eating itself up and you need to flush and refill.
Why test for the freezing point? If you put in the correct mixture of antifreeze and water the last time you flushed the system, it will still be there. If you added water to make up for a leak, yes, the freezing point will be higher.
If your antifreeze is old, then the corrosion inhibitors are depleted and you need to flush and refill the system. The easiest test for active corrosion inhibitors is with a digital volt meter. Put one probe in the cold coolant in the radiator neck & don't touch metal. Put the other probe on the battery negative post. If you read 0.1 to 0.3 volts DC, the corrosion inhibitors are still good. If you read 0.5 VDC or higher, your engine is eating itself up and you need to flush and refill.
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