Block Tester BT-500 Head Gasket Combustion Leak Test Kit - Made in USA

Worked well, easy instructions. Made sure to double check by drawing in air at the exhaust and it instantly changed colors.

Great product, works as advertised.

I suspected that I had a head gasket leak on my 2004.5 LLY Duramax but I needed to be sure, so I bought this BT-500 Head Gasket Combustion Leak Test Kit. It was very easy to use; on a COLD engine, just put the tester on the overflow/coolant fill reservoir snuggly where the reservoir cap goes, add the testing fluid, start the engine and see what the results are. I saw the testing fluid soon start to bubble. Well, that meant that I had air coming in to my coolant, and since it was running, it had to be exhaust air. After running the engine to normal operating temperature, give the suction bulb some squeezes.The blue test fluid turned to a yellowish color, thus indicating that I have a blown head gasket, and/or a cracked head, and/or pulled block bolts or studs, and/or warped sealing surfaces. With any of these potential problems, I'm looking at thousands of dollars in parts and labor. A head gasket job alone is going to cost me $4,500 to $6,000. This tester helped me to easily narrow down what was going on with my engine, and was worth the price because of that.

The only issue I experienced is that it doesn’t fit the radiator cap snug, but it still works.Picked up even the minimal hint of fuel in the coolant. So minimal I couldn’t even small it.But I used a head gasket sealer and now the jeep runs perfectly. No more misfires.

Item was very simple to use and the directions are very clear. It's nice that it comes with the tool and fluid rather than just one.

USER ERROR FOR THE ONES SAYING IT DOESNT CHANGE COLORS. I was disappointed the first time I used it due to the fluid never changing colors. I tested my radiator first and just to test the fluid afterwards I tested against the exhaust and the fluid remained dark blue. I emailed the company about the issue and they notified me than if any coolant at all gets into the test fluid it will not work. I rinsed the test tube out with water, sucked radiator out even lower and then used some fresh test fluid, no blown gasket thankfully. After the final radiator test I sucked up exhaust fumes and it turned yellow immediately. The smallest amount of coolant will not let the test fluid change colors. Side note this is on a diesel truck and it does work for diesels.

High quality construction. Arrived quickly on Prime.BACKGROUNDI used it to confirm (?) the Honda dealer's diagnosis of "coolant was two quarts low -- seeing bubbles in the radiator -- don't drive it -- must diagnose further."After they saw bubbles, they said the opened up the engine and gave it a leakdown test. All cylinders less than 3%. Then they said they needed to do a "five-gas" test, but didn't have time that evening. They wanted to keep it overnight and do more work on it, but that didn't work for our schedule.I kind of wondered why they didn't do that ten minute long "five-gas" test first before spending an hour tearing into the engine. And I wondered why they didn't just spend the five minutes it takes to use one of these testers. The story was a little fishy, or maybe they were just clumsy and less than highly skilled. Anyway, I didn't trust them 100% at that point, so I needed a second opinion.ENTER THE BLOCK TESTER TOOLUsed my tester. Lots of YouTube videos available if you're not familiar. They basically follow the proper directions on the card. Lower the radiator level by 2-3 inches with a turkey baster. Fill the tester. Place tester tightly over the radiator opening and start working the bulb to draw the gases through it for ONE MINUTE.1) I ran the engine warm. Didn't see bubbles.2) I took it on the interstate for a while. Didn't see any bubbles.3) I tried it from dead-cold overnight. Still didn't see any of the bubbles mentioned by the dealer.After each visual test I ran the Block Tester with fresh fluid. Pretty much the fluid stayed imperial royal blue. Fresh fluid for each test.After one of the tests just for fun, I waved it in the exhaust tailpipe plume -- instant translucent hot chrome yellow. So the fluid works, but it just didn't find any combustion gases in the radiator.Also, after one of the tests I kept vigorously pumping for at least another five minutes and it went slightly off of the deep imperial royal blue (almost faintly indigo) toward being still strongly blue but having the slightest hint of aqua. I had some concern. But then I also tested with fresh fluid out in the clean air, and it took again about five minutes of vigorous (spastic?) pumping go get that slightest hint of aqua. Conclusion here, again, is there there were no combustion gases present in the coolant system.I wonder what the Honda mechanic saw?CONCLUSIONThis tester is awesome. Super easy to use. I would recommend it to friend.

Awesome tool works great