Windshield Washer Hydrometer

Great item, works well

As expected

Works great. I used it to check the freeze point of the fluid in my tractor tires. Good thing to have if you have windshield washer fluid in your tractor tires.

WORKS LIKE A CHARM!

Included photos of commercial -20F fluid for calibration (with bubbles and after 5 min), tap water, ~5% MeOH from yellow HEET, ~10% MeOH + 1tsp 20/10 brand conc T880, and 5X of 20/10 brand conc T880.

SummaryThe E-Z Red S104 Windshield Washer Hydrometer saves a great deal of effort otherwise required to determine the freeze point of a methanol-water solution. If proper care is exercised to prevent formation of bubbles on the swing arm, readings are repeatable. Temperature compensation appears to be very good. The main shortcoming is calibration. The 0°F mark being off by 23 rotational degrees, causes me to wonder whether it was calibrated with bubbles on the swing arm. This hydrometer would receive a 5-star rating from me if calibration were better. As is, I still find it useful after adding my own calibration marks.The official instructions embossed on the tester are difficult to read. They are shown here:E-Z RED Instructions1. Fill Tester to line.2. Tap case sharply to dislodge bubbles from the float.3. Hold tester vertical with liquid level parallel to line top of face.4. Read number over the index line on the float.To clean flush with a detergent solution.My preferred instructions:1. With the suction tube out of the fluid, squeeze the bulb fully closed.2. Insert the suction tube into the fluid (to avoid bubbles it is best to keep it submerged throughout the measurement).3. Very slowly release pressure on the bulb until the bulb has fully expanded. Watch for bubbles as fluid enters the tester. If a bubble forms, slowly squeeze the bulb forcing the fluid level lower until the bubble is exposed to air, then continue allowing the bulb to expand slowly.4. Wiggle or tap the tester to be sure the swing arm is free and will wobble slightly above and below the reading.5. Hold the tester vertical with the line at the top of the face parallel to fluid surface. If the fluid is too high, squeeze the bulb slightly until you can see the fluid surface, and level the tester.6. Read the number that lines up with the index line on the swing arm (or interpolate between numbers adjacent to the index line).Erratic Readings:To avoid erratic readings you must fill the tester very slowly, and watch for bubbles as you fill it. Watch closely as fluid rises past the hole in the swing arm. If fluid rises past the hole quickly, a bubble can be trapped in the hole. Also watch the right-hand edge of the swing arm, as bubbles most often form there. One almost invisible bubble clinging to the swing arm adds enough buoyancy to greatly effect the reading. The best way to avoid attached bubbles is to carefully perform the first measurement – by following my preferred instructions. When bubbles attach, they nearly always attach right of the pivot and cause high freeze temperature readings.Calibration:True 32°F point is 5 angular degrees clockwise from the mark. True 0°F is 23 angular degrees clockwise from the mark. The -21°F point is 12 rotational degrees clockwise from the -25°F mark.Resolution:1. The scale has the following marks: Scale:°C/°F: 0/32, -11/12, -17/0, -31/-25, -51/-602. The scale divisions are from 12 to 35 Fahrenheit degrees apart.Temperature compensation:A fluid sample with a 0°F freeze point measured the same at 4°F and 68°F sample temperature. At least over this range for this sample the compensation is excellent!Tips:1. Fluid labeled for performance above -20°F usually has a methanol concentration of 30% to 35%. Federal regulation regarding volatile organic compounds in windshield washer solutions is 35% by weight. The corresponding freeze points from a Methanol Institute chart are -15°F to -25°F. You can reasonably expect that new fluid marked for use at -20°F and above will have a freezing point of -20°F to -25°F, so you can use your new fluid for a rough calibration point.2. The suction tube may not reach the level of fluid in the reservoir. One way to sample the fluid is to lift the rear wiper, and hold a sample bottle under the nozzle while an assistant runs the washer.3. Initially, fluid from the rear window nozzle may have a higher freeze point than fluid in the reservoir (I have seen as much as 18°F difference). If the first fluid out has a relatively high freeze point either discard it or pour it back into the reservoir, and draw more. It appears that with time, the methanol escapes through the long rubber tube from the reservoir to the rear window nozzle.

This product does not accurately read methanol percentages. The meter jumps up and down and is difficult to read. We tested it in our lab because our field people complained so much. Finaly we decided to return them.

I am a Parts Manager at a dealership with a busy quick lube. As part of our fluid checks we always top off the washer fluid. This can be a big expense to the shop supply budget so we are always looking to find ways to save. One way is to buy washer concentrate in bulk but the only problem is regualting the mixture. This item has helped us keep the mixture constant and at a freeze point low enough that we aren't concerned about customer problems. All in all I couldn't be more pleased with this Item