"When either one of the turbo or the EGR valve are inoperative, then there are codes thrown," Warner explains. "This is different for '07, because in the past all you'd lose was 'Jake' function. So that high-side wire, and I believe we've color-coded it red—the scenario under which it would be left to flop around under the rocker cover should be very rare. It's more about a mistake: somebody forgot to attach it, or something like that."
The engine brake will also have to function effectively in a higher-temperature environment on a 2007 engine, but Pacbrake's Sebring doesn't anticipate any immediate issues there: "We don't foresee any change in performance," he reports. "I don't know the long-term effect of higher temperatures and ultra-low sulfur diesel fuel (ULSD), or different oil formulations. That may or may not play into the maintenance of the engine brake, but I don't foresee anything in the immediate future."
The 2007 emissions regulations will effect engine brakes in another way. Because the new standards have necessitated the use of extensive exhaust aftertreatment devices, truckers will no longer be able to modify their exhausts. That means that the familiar "bark" of the engine brake could someday be a thing of the past.
"Typically you hear excess noise because people are not using the proper muffler system that comes out of the factory," says Jacobs' Paré. Of course, this is an issue of some sensitivity to Jacobs Vehicle Systems, as they are working with municipalities across the country to take down road signs that say "Use of Jake Brakes Not Allowed," and either eliminate them altogether or replace them with the non-brand-specific "Use of Engine Brakes Not Allowed."
"What's happening with the '07 emissions is that the truck owner cannot touch the muffler system anymore, because of the particulate filters integrated with the exhaust system," Paré says. "They can't touch the muffler anymore, you can't throw on straight pipes, so we're not going to have that issue anymore. Noise related to engine retarders is not really an issue anymore, because the emissions regulations have mandated what the muffler system is going to look like, and there are no changes to that muffler system. So the noise coming out of there is equal to normal positive power."
Aside from learning to navigate around things like extra wires and redesigned injector harnesses, maintaining the typical engine brake couldn't be much simpler.
"Basically, the tune-up kit consists of control valves and springs, washers, wiring, screws," says Paré. "You're going to get some wear, like anything else. You've got a part in there that's got a certain tolerance to it, and over time there's the opportunity for the component to wear."
"I think some of the key fleet people that do their own maintenance have very good programs," says Sebring. "Today's engines, however, are million-mile engines, and the majority of large fleets do not expect to remove the valve cover during the first four or five years of use, or at least until the warranty period is up. So, we're talking 400,000 or 500,000 miles, perhaps, and they don't expect to lift the valve cover. So therein lies the key. There is a little bit of a thought process that needs to be addressed: you need to remind the fleet people that this is something they need to look at.
"The tune-up kit has hardware involved, and it's a simple matter of replacing the components," he goes on. "The critical component is the control valve, or spool valve. It's a one-way jet valve and it has a tendency to accumulate carbon under the bb and seat and it does happen to leak after a certain amount of time. So (the kit consists of) control valve, springs, solenoid seals and master piston return springs, and wiring.
"There's a solenoid control wire under the cover that deteriorates as well," he continues. "It doesn't require the removal of the engine brake; it can all be done with the engine brake intact and in place. (The control valve has a small 'bb' controlled by a spring on a seat, and every time the engine brake is turned on and turned off, the bb comes off the seat and oil pressure comes under it, between the bb and the seat. When the engine brake shuts off, then that oil pressure drops off and the spring returns the bb to the seat. So it's a ball and seat arrangement, and as your engine progresses in wear, and carbon becomes an issue in the oil, every time the engine brake is on and off, the ball and seat is subjected to whatever contaminants are in the oil. So as you get contaminant buildup on the ball and seal, that unit becomes a leaky product rather than a zero-leak product.)"