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+--- Thread: 871 Jake Brake (/showthread.php?tid=10513)
871 Jake Brake - AWTrans84 - 02-15-2026
I want to thank you to Rawze for letting me into his forum. I have an ISX 871 that has Jake Brake problems. On 3rd stage (vgt stage) the Jake just doesn't slow me down like it should. It will boost up to 20 or 25 psi and then go down from there instead of staying to slow the truck. There is pretty much no difference in stopping power from 2nd to 3rd stage. So far it's got new Jake solenoids, new rocker shafts, rebuilt the rockers, new turbo actuator and still has an issue. I bought the truck used and the turbo has no ID plate on it so I can confirm the turbo that's on it. Could this be an issue with the turbo itself? I've never run an 871 only a 2250 and the 2250 was incredible with the Jake power. I know they ran smaller turbos on the 2250, but I can't believe the 871 would just be the bad with the 3rd stage Jake.
RE: 871 Jake Brake - mikkhh - 02-15-2026
Copy the file from ECM and send it for a review. Bad programming could cause all of your issues.
Read more here to get started -
https://rawze.com/forums/showthread.php?tid=8425&pid=72945#pid72945
RE: 871 Jake Brake - Rawze - Yesterday
yeah.. if it has delete program.. it needs to be reviewed. - Who knows what someone might have done in there.
Also do an injector leak test(s)... if injectors are leaky enough, then the jake will also be weak, as some cylinder(s) might be partially firing with leaked fuel.
info: http://rawze.com/forums/showthread.php?tid=7747&pid=67948#pid67948