Pittsburgh 63726 diesel compression tester set

[Eric a1cnc]

I bought this set at harbor freight cheap as they are discontinuing it. It has the pencil injector adapter I needed for my case 188 engine but It doesn't seem to work right. When turning the engine over it would build pressure on the 1st compression stroke but the pressure would drop immediately. I thought it was the cyylinder first untill I did the finger over the hole test and it is fine. I noticed it has no check valve only the pressure release valve. I tried to pull the pressure relief valve out to try to clean / fix it but it was loctited in and the metal was so thin it snapped right off.
My question here is, How is this supposed to work without a checkvalve?

I will call pittsburgh on monday to see about a new pressure relief valve.

https://www.ebay.com/p/11024420141

 

[Old Doug]

I dont think it wouldnt work i had one that wouldnt hold and it didnt read wright but it also could be something else. Why are you needing to check it? I always wanted to get a leakdown tester i got one last year but havent realy got to mess with it. Something i didnt know and hurts the way i wanted to use it is the engine needs to be wormed up. I thought if i could test a engine that wasnt running or in a vehical i would know a little about it.

 

[Eric a1cnc]

I wanted to check it because after rebuilding it #1 cylinder was running much cooler then the other 3 cylinders. Turns out it was due to a bad injector. But I figured while I had the old injectors out I wanted to have proof of what condition the cylinders were in. I hate questioning things when I can test them with the right tool.
As for a leakdown tester and needing the engine warm, Yes the preferred method is to test a warmed up engine so all the parts are expanded. If the engine won't run and you get a horrible leak down that pretty much backs up the question of IF it can run