Pressure Testing 6.0 Injectors

ETS · September 23, 2011

I have 06 F350 dually in my stall as seen on previous post. Shut down climing mountian heavily loaded. Owner stated heard noise and it shut down. As Mr. Clayton said it needed STC Fitting delete. Pressure tested through sensor port. Huge leak from both covers and crankcase. Pulled turbo and pump cover. Fitting is OK. Installed my own pressure test fitting at pump block. Noise louder right side. Pulled right cover. [Noticed ARP Studs and Fresh Head Gaskets] Huge leak #4 injector. Pulled manifold 1/2 of the top steel and rubber-o rings missing. Replaced injector, Stand pipe, [looked for pieces no luck] Reassembled and retested. Very small leak from same area. Barly audible and I cannot feel it. Unable to pinpoint the leak. Pulled manifold again and installed home made blockoffs. Pressure tested manifold holds shop air with no leaks. My question is; Is it normal for a new DRY injector to do this? It has never had fuel in it. I am going to switch holes on injectors to see if leak moves also in the morning. Stand pipe is new design 12mm. Never had one not seal completely before. By the way left side is perfect no leaks at all. Any ideas will be greatly appriciated. All parts were lubricated with clean engine oil on assembly. Customer is in hotel calling 5 times a day. Which doesn't help!!

Brad Clayton · September 23, 2011

That is normal, the truck must be run or driven after replacing high pressure oil components or you will have erroneous readings with air checks. I was being humorous with the STC fitting comment, does it have the new one piece design installed?

joshbuys · September 23, 2011

It's normal to have a small leak at the injectors, especially a newly installed one, it's the pressure that forces these seals to seal to the manifold rail. Since our shop air is only about 150-170 psi it does not have enough force to completely seal against the manifold. Even on an injector that has been run you might find a slight leak when air testing, but it will seal back up when you run the truck. We are looking for the 'big' leaks.

ETS · September 23, 2011

Yes I caught the joke. Trying to be funny myself, Guess not. I will put it back together in the morning and run it. It does have late model fitting. Thanks Again.