Compression test Tool check in but cannot check out.

BigWalt · April 30, 2014

2011 F350 ...Came in for contaminated fuel. Other tech Replaced everything, pump, filters, PCV valve, and injectors.Got it running, misfiring cyl #4relative compression test passed but I do not rely on it. Told him to do manual compression test.Correct tool number is 303=1515He installed the tool and did the compression test, could not get good reading few times, needle on the compression tester gauge goes up and back to zero rapidly.

Told him to check compression on cyl #3.Now the tool 303=1515 cannot be unscrewed from cylinder head.What the hell did it happen?FYI.....I went back to WSM and double check different model year, all got same tool number 303=1515.

BigWalt · May 1, 2014

fixed.............Tech over tighten the compression adapter tool.what a relief.......

Fordracer · May 1, 2014

I used to have that problem on all diesels so now I screw it all the way in and then back it out a 1/4 turn before checking compression.. I wonder if the high compression in diesels heats up the tool and makes it expand causing it to get stuck.

Matt Saunoras · May 1, 2014

I had the same problem with my last 6.4 compression check. Adapter got stuck and I would up spinning my hose fitting and ruining it. The new adapter from snap on is a redesign.

Keith Browning · May 2, 2014

Mine did this too the last time I used it. There used to be an o-ring or a nylon washer on it if I remember correctly. It is no longer there. Could this possibly have something to do with it?

Matt Saunoras · May 2, 2014

I lost my o-ring a long time ago, I saved some old 6.7 injector return line o-rings and used those. It was close to the same size and worked fine.Honestly I don't know why my adapter got stuck. I'll take some pics of the new vs old

Keith Browning · May 2, 2014

Well I got a little pissed and almost destroyed it trying to loosen it.

Matt Saunoras · May 2, 2014

oh I did ruin mine too. The hose would spin and I thought I was loosening the adapter too but that wasn't the case, eventually I just yanked the damn hose out and got a socket on the adapter.