I'm in the market for a compression leak-down test set in the $100 +/- range. I think I've found the unit I want - OTC 5609. However, I note the gauge scales top out at 100 PSI. I've seen posts here on C.O. and other places that indicate our Olds BBs can push up to 106 or 109 PSI. Should I put aside the 5609 and look for a unit with higher PSI testing capabilities?

What are your thoughts? What make/model of testers do you guys use, or suggest?

Thanks in advance for any and all feedback.

 

I would buy the OTC leak down tester. I have an Innova compression gauge for my Olds (gas engine) and it works great. I bought a Lang compression gauge for my truck (diesel engine) and it died after using it to test 3 cylinders. I ended up buying a HF compression tester to finish doing the compression test on my truck.

 

Thanks for your input, Jesse.

Rich

 

In my experience with using a leak down tester, when you reach about 90psi, the engine assembly might start to turn over. This is not desired. You want static readings to rely on. I"m not surprised that the gauges supplied don't read much higher.I will add that my experience has all been on worn factory low compression engines. Leaks down tests are another tool to help diagnosis in conjunction with other tests and various equipment. Keep in mind, this test is done on a engine that isn't running like some others test are. Their simply a snap shot of a bigger picture.

 

Thanks, Don.

 

Leak down testing is different than compression testing. You want a compression tester to read over 160psi. A leak down is a percentage test, so you just want enough pressure to get a stable reading. So as said, under 90psi is fine.
Some tool makers will make combo units, or reuse parts, hence why you see a higher range gauge on some leak down testers.

 

Thanks for the additional info, oddball. So it sounds like the OTC-5609 is the way to go at this point.

I'm still open to hear opinions and suggestions. Payday is the end of the week, so I have a few days before I pull the trigger.

Thanks to all who've played so far!

 

Compression testers register the pressure built in the cylinder when the piston comes up on the compression stroke Leakdown testers register the pressure LOST when air is pumped into the cylinder, when the piston is stationary. Compression testers and leakdown testers do TOTALLY different things.

OTC is a four-letter word to me. I got totally screwed on a "Marathon Lifetime Warranty" when my floor jack broke. Bosch bought OTC, they've gone straight down-hill ever since. Everything got outsourced to Asia.

I made a long post about leakdown testers on your other thread. Hate to have to repeat it all here.

https://classicoldsmobile.com/forums...tester-145909/

Why would you start another thread on the SAME subject?

 

Schurkey - Interesting! I must have been on auto-pilot I can hardly believe that I initiated two threads on the same thing a week and half apart I must be losing my mind

My apologies to the folks trying to follow my thought process.

Now I need to go over to the other thread and see what didn't sink in...