Review on OTC 5021 Universal Diesel Compression by Owen Houser

If you have a 7.3 Powerstroke these cheap universal/special diesel compression test kits are a waste of time and money. I have one that says on the box that it works with Powerstroke 7.3 and it comes with all sorts of adaptors, including the right thread for my glow plug holes, but the quick connect doesn't clear the notch in the head casting. If you see it, nothing will happen unless it's custom made - it should be long, with the end of the sleeve many inches above the threads. An OTC adapter is ideal, but you'll need the right type of quick connector on the gauge side, so you'll also need an OTC gauge. Would have saved me hours trying to get something to work plus about $50 in useless adapters I have (now I destroyed the best part of a cheap test kit trying to make my own adapter) .