ISX CM870 Jake Brake Repair

[same101us]

Hi guys
I need advice on a ISX CM870 Jake Brake repair. What do you guys advice i replace to make them work better? Truck has about 800,000 miles on it and 100,000 on a in-frame overhaul.

[Wiseman]

What truck? How many solenoids ? Are they functioning properly ?How many positions ?
What is commanded VGT position on them ?
What's the boost @ 1700 rpm on highest setting ?
How old is your turbo ? Have you abused it with high EGT ?
Have you inspected it lately? What's the boost under full load ?
Have you done overhead adjustments after the overhaul ?
Have you checked for exhaust and boost leaks?
What do you mean by " to make them work better" ? Compared to what ?
What's in your ECM ? What was involved in the overhaul?

[same101us]

2007 Peterbilt 379 with 2 solenoid jake brake. Turbo was replaced when we did overhaul. They worked good up on till now. I noticed sometimes they just sputter before the latched the 3rd stage. I am planning on doing the first overhead adjustment after overhaul. Everything is original under valve cover. I read on here somewhere where guys are replacing the springs and the rocker shafts and i need more info how to go about it.

[Wiseman]

(12-23-2017 )same101us Wrote:  They worked good up on till now. I noticed sometimes they just sputter before the latched the 3rd stage.

If so , most likely sticky solenoid, bad harness, bad harness connections that prevent instant activation and proper oil flow .
Check coil resistance and voltage for fluctuations.

[Nilao]

Mine did that sputtering on high. Low worked fine but 2-3 was hit and miss. Turned out to be a loose connector on the rear solenoid. Plastic covering had fallen apart so I just crimped it down with a pair of pliers and put it back on. Works like a champ now. Mine had 130k on the Inframe as well.