Truck Repair: C Brake Springs Breaking, oil hole, heat gun

Question
Good day sir..1988 cummins 444  not electronic...  C BRAKE SPRINGS commonly breaking..I replaced them and engine always worked fine after, except for this time. After replacing #6 inner & outer springs engine has developed a mis.....same as if you cracked a fuel line to bleed it...No tests have yet been done...Where should I start?  Any help would be appreciated        Thank You

Answer
Dont see those much any more :)On the manual engine,you have to take engine brake off to check for misfires if you dont have a heat gun.You take C brake off & plug oil hole to brake somehow.We made a plate with a rubber piece made on it to slide over stud & tighten a nut on it.With the brake off will let you know if the brake sticking is causing the miss or not.