Wasted a whole day on a bad coolant test strip kit

Had a truck with a slow overheat. Bought a cheap coolant test strip kit from a parts store. The kit said the coolant was fine, so I spent hours checking the thermostat, water pump, everything. Finally borrowed a real refractometer from the shop next door. Coolant was totally shot. That kit cost me $25 and a full eight hour day. Never trusting those strips again. What do you guys use to test coolant?

3 comments

3 Comments

angela_park9d ago

reese_hill nailed it with that squeeze bulb tester. I switched to one of those after a similar strip disaster, and it's been night and day. The strips just aren't consistent enough for something that can cook your engine. I keep a refractometer in my toolbox now for when I'm doing a full system flush, but for a quick check before a road trip, that squeeze bulb is solid. It's cheap, you can read it in two seconds, and it doesn't lie to you like those paper strips. Have you tried the bulb style yet, or are you still leaning toward the refractometer as your go-to?

reese_hill2mo ago

Man, I used to swear by those test strips too. Figured they were good enough for a quick check. Had a similar thing happen on an old car of mine, strips said it was fine but the heater was cold. Bought a basic antifreeze tester, the little squeeze bulb kind with the floating balls. It's not lab grade but it's way more reliable than paper. That strip box is probably still in my garage somewhere as a reminder.

sandrahayes2mo ago

You know what, maybe the strips get a bad rap. I mean, did you check the expiration date on that box? I've used them for years on my own cars and never had a problem. Could be you just got a bad batch or they got left in a hot truck or something. A refractometer is overkill for most people just trying to see if they need a flush. Those strips are cheap and fast, and they work fine if you buy them from a place that sells a lot of them so the stock is fresh.