- Nov 19, 2020
- Eastern NC
Just a quick PSA, I've already returned it and didn't take pics. We all know Harbor Freight can be hit or miss, but the compression tester is a MASSIVE miss. Dangerous even. I bought one to do a compression test on a 95 Wave Venture 701 I got to work on, and on a rebuilt engine it was only showing 80PSI on one cylinder and 70 on the other. That is obviously far too low and I was worried I was gonna have to ship it back to the rebuilder. I did some quick googling and came across a lot of info about the HF testers having a design flaw. They don't have a schraeder valve at the cylinder end of the hose- only at the other end, so you end up lots of PSI short of where it should be as the air in the hose gets compressed and the hose stretches. I rented one from O'reillys and it gave me 155PSI and 145PSI. For a similar price to the HF one you can get a Bosch one on Amazon that is spot-on with the oreillys one. Supposedly some of the HF ones *do* have schraeder valves on them but not all of them.