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

Product worked great

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.

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.

Decent bit of kit. I was impressed by the construction and utility of the tool. It consists of a thick-walled plastic tube capped at both ends by hefty rubber stoppers. A small amount of liquid reagent is added to the tube, which is then pressed into the radiator filler neck. The supplied rubber bulb is then pressed against the top of the tube and pumped slowly several times. This draws gasses from the radiator through a porous metal aerator, which bubbles them into the reagent. After a few pumps, the reagent turns from blue to yellow if hydrocarbons are present. There is a check valve in the bottom cap to prevent the reagent from draining out and another check valve in the bulb to ensure that it draws rather than pumps.I successfully used this tool to (unfortunately) confirm that the head gasket of my 2003 Civic was leaking.One difficulty I had was that it was easy to accidentally draw coolant into the tube (which ruins the test). I did this twice before finally draining enough coolant from the radiator to have a successful test. The instructions advise removing enough coolant to provide a few inches of gap before beginning the test, but I found that once the car warmed up, the coolant level increased to the point that it was necessary to siphon off even more. A design change that would help here would be to provide a floating ball valve (similar to that in a wet/dry shop vacuum) to prevent liquid from entering the tube. When I finally did a successful test, I was still concerned that the yellow color of the reagent, which is very similar to that of Prestone antifreeze, might be due to contamination from coolant, but I noted that the reagent in the tube was still at its original level (at the "fill line" marked on the tube). Afterwards, I experimented with adding antifreeze directly to reagent and determined that it takes a substantial amount of antifreeze to change the color of the reagent to pure yellow. Nevertheless, a reagent that turns to a different color than antifreeze would be a useful change, if that is chemically possible.My only other complaint is that I discovered that, while the top rubber cap is designed to be removed for cleaning, the bottom cap is not. It is attached by an adhesive, but the adhesive is too weak, and the cap can be accidentally removed without much force. After it is removed, it cannot be reattached securely without using more adhesive. This should be corrected by either making the bottom cap removable by design, or by using a strong adhesive that prevents the cap from being removed at all.Some other info: there is enough reagent in the supplied bottle to do several tests. According to the instructions, the shelf life of the reagent is about one year. Spent reagent from a positive test (that has turned yellow) cannot be reused, but it is not clear whether there would be any negative effects from reusing the reagent from a negative test.

Good for testing for a blown head gasket. Easy to use. Good for determining if you have a serious issue or not.

Product works as advertised

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