isx 15 jake brake shuts off engine when in use

Red light is for what? Low oil pressure? Need diagnostic computer to connect for codes and test.
With newer engines nothing easy to fix.

 

Sounds to me like one of your jakes popped a spring in one of the Jake housings. This will cause the jakes to hang up once engaged and then shut off. Whatever plunger spring that broke will cause that plunger to hang for a while till it makes it way back to the top. This causing part of that Jake to remain engaged even when shut off and still under acceleration. I don’t know if it’s easy for your year Cummins. Took me just shy of 3 hrs for me to rebuild all 3 being since I have a cat. Rebuild kit is like 150 bucks and the kit does all 3 Jake housings

 

ISX's have 2 jake solenoids and then 6 jake rocker arms which do all the work. (650$ ish Canadian each)

If the stop engine light comes on first thing to do is read the codes.

 

so totally different than cat? im asking just for my own knowledge. could something similar be happening t this guys jakes or is that not posible based on ow those jakes work

 

Yes different then the Cat setup as far as hard parts. Theory is still the same.
When the solenoids are activated the put oil towards the jake rockers. Jake rocker sit doing nothing on a detent til oil pressure activates them and then they ride on their own cam lobe to actuate one exhaust valve.
Check engine light only when jaking means either wiring/solenoids are faulty or possible low oil pressure when jakes are activated but haven't come across that yet.

 

good stuff thanks

 

Only 2 solenoids? Where's the 3rd stage jake come from? VGT?

 

Yup. VGT is used in conjunction with stages.