I love my Mityvac Pressure Tester

[DMC1890]

I just last week received my Mityvac pressure tester ($43 from Amazon). I bought this after reading a procedure suggesting using one to bleed the cooling system. The same procedure also probably mentioned getting the Toby radiator bleeder valve, but I stupidly have not yet done that.

I was previously aware of some leaks, and sure enough when I pressured up to 10 lbs, I smelled a telltale ocean breeze, followed by some dripping around the water pump. I had replaced the water pump a few years before, but the car had barely been driven since then. I decided that whether or not the water pump was bad, I should go into the VOD to see if coolant had puddled up there. It had indeed, and after drying out the valley, I retested, and found that the problem was the starboard pipe-to-water pump hose connection at the pump. After fixing that, I pressure-tested again, saw no leaks, and the VOD remained dry. Without the pressure tester, I would have to seal up the VOD, start the car, hot-test it, and still not be able to see if I was leaking into the VOD.

I've just now re-read many threads on here regarding cooling system leaks, and some of the wisest contributors (most of whom are named David or Dave) always say to use a pressure tester. I know you can 'rent' these, and also there are better and more expensive units to buy. But for me, this was $43 I am glad I spent.

[novadmc]

I had a similar issue last year. clamp needed tightening on the pump-to-y-pipe hose.

saw coolant with inspection scope. put about 5-10psi on the system with the mitivac and with the camera, saw the coolant start to dribble out of the hose fitting.

annoying that i had to remove the entire intake manifold to then simply tighten a worm drive clamp, but them's the breaks.

mitivac makes finding leaks a breeze, even if fixing them isnt.

[David T]

If you are going to do that kind of work yourself for the pleasure and/or savings, then it is best to get the equipment and tools necessary to do the job right. Glad to hear it turned out well. If you do, indeed have a tight system with no leaks, you should not need the so-called auto bleeder. I consider it just a Band-Aid for a system that leaks and needs to be continuously bled of air. If you properly bleed all of the air out of the system, any air still trapped will work it's way out. If you find it is filling up with air afterwards you either have coolant leaks or a bad head gasket.

[DMC1890]

David T, you are of course one of the David's that I referred to as suggesting that a pressure tester be a part of many procedures. Regarding the bleeding, it wasn't the 'automatic' bleeders that I was thinking about installing, but Toby's radiator manual bleeder valve.

[David T]

To do an initial bleed on the rad all you have to do is loosen the small hose on top of the R/H tank. That line IS an auto bleeder of sorts and will be able to handle any air still remaining after the initial bleeding. If you still have the plastic tanks on the original rad be VERY careful because the plastic gets brittle and breaks easily after 30 + years. By now everyone should be getting rid of that original rad. It's time.