2008 c15 engine brake

the rocker shaft studs are not relevant to oil supply on the acert. however you can identify the newest version of the stud by removing one, if it is a straight shank all the way up you should replace them, they will break. if it is machined thinner under the hex of the stud approx 1" long you have the latest stud version. you should check them all to be sure.

 

not to argue but yeah one of the studs does supply oil the the jake on an acert. well maybe not the three studs but the one that looks like a bolt. that goes down through the rocker shaft.

 

my bad yes just the bolt

 

Is it weak on all jake setting or does it just feel like you've dropped one bank?, does it sound weak or feel weak? there is a difference.
Above all else make sure the overhead clearnaces are right, after that-
If they sound weak-
If the jakes are weaker than unsual on all 3 settings you most likely have an oil supply issue, look for a spun cam bearing, or a massive oil leak under the rocker covers, maybe a missing gallery plug in a jake/IVA housing.
Typically a cracked housing will only result in one weak bank but if they're broken bad enough you will see all the jakes get weak.
Something else I've seen but is unlikely in this case since they were ok for a while after the work was performed is one or more rocker shaft installed upside down, that creates a big oil leak.
It isnt possible to put the bolts in the incorrect order to block the oil supply to the jakes on the Acert as the housing prevents the studs and reduced shank oil supply bolt being mixed up.
If they sound ok but a feel like they are weak in operation-
Check for boost leaks and turbo condition, good jake operation requires good boost from the turbos, if you aren't getting the boost they will be weak.

 

There is a tool you can get for jake brakes to measure the pressure supplies to the jakes, it screws in where the solenoid goes, unfortunately the Cat brake doesn't have that option, you can measure oil pressure at the air compressor feed line, the will at least tell you there is supply to the top end but the cam bearing and idler bearings are downstream of this point so you would have to check those things the hard way. Has anyone cut and insepcted the oil filter? If you have a spun cam or failed idler bearing there should be some metal in the filter.

 

Mine went into the garage last nite for the same thing (BSX) 5-6 actuator code I got over 1,000,000 on mine. My CEL blinks if tou hit a bump just right, I thinking harness I'll let you know as soon as I find out.