OTC 7991 Cooling System Pressure Tester Kit

While there's no argument OTC doesn't make the best tools in the world, they make very good tools at very reasonable prices. The 7991 is no different - it brings professional-level capabilities at a DIY price. I'm happy to have added this cooling system pressure tester to my shelf full of save-my-bacon OTC equipment. ;) The singular best feature about this tool is the air bladder that seals the pump against the cooling system's filler neck. Even though getting the bladder to exactly the right height is a small pain, it's far less annoying than keeping track of and sorting through a stack of filler neck adapters. There is also significant peace of mind knowing that this tool will very likely work on virtually every car to come out down the road, rather than fretting that you'll need to buy more adapters when someone changes a thread or diameter. (In my particular case, I've already got an oddball car that has a unique filler neck - so the OTC tool was the obvious choice!) Operation is pretty straightforward - adjust the depth of the bladder, adjust the height of the clamp, slide the pump valve to "Bladder" and inflate until the indicated location on the gauge - just a few pumps. Slide the valve back over, and pump up your cooling system to the appropriate pressure (15-20lbs, usually). Look for leaks or listen for hissing - and of course be aware that if you've got a couple problems, fixing one may cause another to show up, so keep retesting until pressure is held. My sole complaint about this tool is the slider valve. Quite honestly, it sucks. If you don't have a quick hand you can lose bladder pressure when moving between "bladder" and "system" and that can lead to a spray of coolant. Also, the slider is so easy to move a fly landing on it might be enough - just the slightest nudge results in the same coolant spray. In order to use the pump effectively I had to steady one hand against the body of the car - a slight tug on the hose moves the slider and then you start over (and make a mess). In the same vein, depressurizing the system is an art form - you need to gently move the slider right into the middle to release pressure. Too little or too much can result in nothing happening or - you guessed it - a mess. The slider is a minor nit - I'm more than willing to live with this idiosyncrasy given the functionality, flexibility, and price of the tool. It's a thoughtful design that just needs some tweaking. Regardless, I found my leaks in a few minutes and I saved myself hundreds of dollars at a shop. For my application it wasn't necessary, but if you've got tough to find leaks I'd probably recommend picking up some cooling system dye and a UV light to compliment this tool. It's cheap, and might save real time.

Have used this pressure tester on 4 different vehicles so far and it has done its job everytime. Have used it to find a very small leak in a lower radiator hose and also a slight leak from a bad thermostat gasket that I never would have found when the engine was running because it would have burnt off on the block, but not enough to see the leak happen. Have used it on a Nissan but have not had a used for the 3 adapters. The only thing that I have noticed that could use improvement is the strength of the metal clips springs that grab you radiator neck. When tightening down the grey knob on top sometimes one of the clips will slide off of the radiator neck. Just go as lightly tight as you can on this part and pump up the bladder slowly if this happens to you and it should seal just fine. Or tighten as normal while holding the clips and have someone else pump up the bladder. Once the bladder is pumped up it will hold itself and the product will work great. Yes I would buy this again or recommend it to a friend it is a good product.

Worked well on my 2000 Chrysler Town and Country, helped me find small leak in Radiator. I have owned it since 2014 and upon the fourth use the bladder failed rendering the tool worthless. Low quality. Too pricey for the quality. Would not recommend.

The OTC 7991 is not quite as easy to use as the typical "Stant" style pressure testers, and it does not do radiator caps, but for the price, it is a good deal, and eliminates the need individual adapters. I would recommend it to any tech that services multiple makes / models.

I wish I would have gotten one years ago it took me 5 minutes to find a tiny leak I wouldn't have found without it. I've only used it on a ford van with a fairly traditional radiator cap, I didn't need to use either of the included adapter so I can't really comment on the universal fit aspect.It seems well made but I worry that the rubber bladder that makes the seal will degrade over time.

I use it professionally and it performs well. A little tricky to set up, but that is the price to pay for a universal fit.

Returned and chose another set

I get scared every time I use it. I don't want to break the bladder because I can't find the replacement listed.

Works well, however the one drawback is their is no way to test rad cap.

Très bonne outils.

does what it says very good value