william Posted August 2, 2017 Share Posted August 2, 2017 I am trying to run a crankcase pressure test on 08 250. i do not have the tool the book calls for, 303-758. i found one in the shop that i believe is used on the 7.3. i was told it would wok but i am questioning it. the complaint on the truck is that it has oil consumption. i have checked relative compression and power balance and checks ok. fuel trims are less than 2 on all cylinders. i have not checked manual compression. with the old crankcase tester i have 5 psi blowby. would this be accurate or should i make the shop get the correct tool? Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted August 2, 2017 Share Posted August 2, 2017 I think those crank case pressure test adapters are engine specific but the 6.0L and 6.4L do use the same adapter. The obvious difference is the type of mount used to connect to the oil fill but there is an orifice in all of them that is likely different and will affect the reading. With that said, the 7.3L adapter will likely provide you with skewed readings even if you can screw it on. Somebody correct me if I am wrong. Quote Link to comment Share on other sites More sharing options...
forddieseldoctor Posted August 2, 2017 Share Posted August 2, 2017 I agree with Keith. Right tool is essential for proper results. Quote Link to comment Share on other sites More sharing options...
william Posted August 3, 2017 Author Share Posted August 3, 2017 Thanks for the reply. I figured they were different but I was under the impression that the previous tech used this tool but I did not think I was getting the correct results. Quote Link to comment Share on other sites More sharing options...
cbriggs Posted August 4, 2017 Share Posted August 4, 2017 You could build one. The orfice hole size would be the only critical measurement. I (Or someone that has one handy?) could measure the hole size for you. Quote Link to comment Share on other sites More sharing options...
Fordracer Posted August 5, 2017 Share Posted August 5, 2017 I was told in class that you can use the 7.3 adapter on the 6.0 and 6.4 and the other way around you just need to use the specs for the adapter you are using since the holes are different sizes. Quote Link to comment Share on other sites More sharing options...
lmorris Posted August 9, 2017 Share Posted August 9, 2017 They made the holes smaller for the 6L and 6.4L so as to provide a more accurate reading. Use the 7.3L specs. Remember to disconnect the CAC tubes to eliminate the chance of a bad turbo messing the readings as well. If you are pushing 5 inches with the 7.3 adapter, I would say you have an issue. 3" is max for a 7.3L. Quote Link to comment Share on other sites More sharing options...
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