Lisle 75630 Test Fluid

Works as intended.

Used this to confirm what was pretty certain, a head gasket leak. Sure takes the guesswork and time out of detecting head gasket leaks. I was already 95% certain one or both head gaskets were leaking using cylinder compression and leakdown tests and radiator pressure test. I like the ability to shutdown a cylinder bank and test for a leaking head gasket on one head or the other. Caution, if you do this, you will most certainly trip computer codes and the engine service light on the dash. You need to be aware that you have to check that your code reader (if you have one) will reset the engine service light. Not all will. Many will clear codes but not reset engine service light so you may have to got to a shop to have light reset. Some car models can be manually reset or there is some trick to reset. One of the other anecdotal aspects of this test is that you can tell which cylinder bank is leaking faster or slower. The color change for my testing was gradual, ie it went from blue to green to yellow. This shows that the color change is relatively proportional to the amount and rate of leakage. The color change for the right bank was pretty quick and the color change for the left bank took several minutes. I ran this several times on both a hot and cold engine. The results were generally reproducible.

NIASE MASTER TECH REVIEW Good value4 professionals. Purchased this item after a once over. I found it effective w/1 caveat. Be careful not 2allow fluids2 enter the intake during testing. This could result in a catastrophic fluid lock of any effected cylinder. In my case the blue color was already rapidly fading when a large bubble erupted directly into the cylinder pushing the test reagent &a considerable column of water up toward the top& out into the intake! I promptly shut the engine down2 avoid damage. BTW, if u c bubbles in the coolant reservoir, creamy white discharge on the engine oil dipstick or the same in the coolant; then u don't need the comfirmation granted by this kit. Any 1or all of the3 ARE comfirmation of a blown head gasket, or of a cracked head, or of a cracked engine block.

I expected it to change color because of all the bubbles getting into my radiator system and then going to my overflow and making it bubble. It did NOT change color. That leaves me wondering if the bubbles are simply plain air instead of combustion gases. I'm testing a 1993 American Eagle motorhome with a 6CTA 8.3 diesel engine. Runs great, but over heats because the pressure in the radiator opens the radiator cap, letting the fluid get hotter because the 15 lbs. of pressure are gone. I "THINK" it might be the Cummins air compressor having a leaking head gasket. The radiator fluid runs through there to cool the compressor and IF that head gasket is leaking, it could pump air into the radiator fluid. I'll get back to you when I get it fixed and let you know. Until then, I'm going to put the exhaust fumes from the tailpipe thru the fluid to see if THAT makes the color change.

This kit is super easy to use and I prefer this style as I already have a hand vacuum. I use the same one as for brake bleeding. This as opposed to the other kits that have a built in bulb but that's a spot where it can break and render the kit useless. Its super easy instructions to follow and can give you a look to see if exhaust gases are present or not in the coolant knowimg if there is head gasket integrity issues.

Haven't had a positive test on it yet but I'm sure it'll work. The instructions are written incorrectly as it describes using either a red or silver fitting connecting the hose to the tool but there is no red fitting. The one with 2 small holes in the side was apparently meant to be red as that's the correct one to use with engine vacuum and the other without the side holes is for a hand pump. When I used the appropriate engine vacuum fitting, it wouldn't pull air through it at all. I tried taping off one of the 2 holes as someone from lisle suggested but it still wasn't enough so I went with the hand pump fitting and it works but not well as it pulls air through so fast that it just looks like suds. I'll probably modify the engine vacuum fitting to make the holes a little smaller to try and make it work like I'd expect. All in all it'll probably get the job done but if you plan on running into blown head gaskets often enough, I'd go for the more expensive one that has a bulb built into it

Glad I found this on Amazon. I haven't opened the bottle yet, but if it works as good as the stuff that came with my combustion leak kit (which I expect it will, since the bottles are identical), it will work like a charm and at half the price of ordering a replacement from the catalog. Make sure to test your results. That is, if a combustion leak ISN'T present judging by the lack of color change, exhale into the tube and see if the CO2 in your breath is enough to cause the blue to turn greenish-yellow. If not, then the chemical itself is faulty. The process I use is to let the car idle for about 5-10 minutes with the hood open, then get in and raise the RPMs to about 1200-1500 while in Park or in Neutral with the parking brake engaged. Then, I get out, open up the expansion tank cap, and a vacuum line to the engine, and use the vacuum to draw whatever gas is present in the expansion tank into my testing kit tube. I let it do that for about 2 minutes - if the color doesn't change, you're good to go.

Over the years of using a block tester, I never thought there could be a difference in quality of the fluid being used. Make no mistake this fluid is the fast responding to combusting gasses. When compared to the competition out there this fluid out performs in every aspect. Good quality, easy to use, easy to store and it doesn’t leak.