(Today )Rawze Wrote:  A)> Stat by ensuring the injectors are not leaky. Any fuel seeping into cylinders will make Jake get weak because cylinders will partially fire.
info: https://rawze.com/forums/showthread.php?tid=8728&pid=75483#pid75483

B)> Overhead valve adjustment needs to be to spec... and not some idiots offsets. The Jakes are hydraulic activated and messing with height settings only serves to make a piston strike a valve if it is set wrong.

C)> Make sure the wiring connector to the jake solenoids is not loosey-goosey. A common issue with jakes on the ISX.

D)> Check the boost pressure, what it is cresting at during jake operations, and it on its highest settings?. Different year model ISX engines have different max pressures that are seen.

E)> Ensure oil pressure is not getting too low when engine is hot.. it should be 43+ all the time, and above 32 psi even if oil is really hot after a hard pull.

F)> Worn out rockers and/or rocker shafts will cause oil pressure losses and weak jakes on the top end.

G)> Make sure no idiots have "tweaked the jake" or other settings in the ecm .. this is common when some moron does a delete and jacks with things they should not be messing with.


NOTE: A red engine already has one of the strongest jakes in the industry... cummins prides themselves on it.. so if it is otherwise operating properly and you still think its not enough.. then you need to look at other factors instead of trying to "make them stronger than factory".,. because all you will end up with is a destroyed engine where a piston strikes a valve if you go messing with it. - Seen it too mane times.. especially with bad delete files and someone tried to make them stronger, etc.