Air flow escaping at EGR Cooler connection to ex. Manifold

[Rawze]

(08-19-2025 )wrench buster Wrote:  Hey there , I have a 2012 Freightliner M2 Cummins 8.3, and it has air escaping at the flange connecting at cooler to manifold connection. I installed a new gasket and it’s the same thing. I noticed there was LOTS of pressure when a disconnected the crossover tube from cooler to EGR cooler and the air leak stopped. It seems like the EGR valve was not flowing the EGR air to the intake. Can anyone shed some light on this situation.
I have a code for high DPF dif pressure.
Thanks

... And aside from the DPF faults... it is quite normal for the exhaust circuit (and parts of the egr circuit) to have quite a bit of pressure in it with engine is running. The exhaust manifold (and piping to the egr valve) can have as much as 80-90+ PSI pressure in it under full engine operating loads. If it is leaking at idle, then something is wrong with the pipe connection, gasket wrong, or something else, etc.