Exhaust brake sound changing

[jkern]

I have noticed over the last 1k miles or so that the sound of my EB is "worbleing". It sounds like a siren on wail, slowly getting louder and higher pitched then backing off, and then doing it again. it seems to be retarding the truck properly, maybe just a little less as the sound lessens. It does it with or without a load. I doubt that it is dirt or soot, as i run with it on (engaged) all the time, every time. Anyone else have this experience? Hope it is not the next failure i am looking at!

 

[mfurrh55]

you leave it on all the time, maybe it's wore out, I have a jacobs brake and i don't run mine all the time , just intermittently to keep it from sticking, Monte

 

[jkern]

I doubt that is the case. All the mech's seem to agree use it all the time to keep it clean. Also on the 4500 and 5500 series trucks the EB is defaulted to on all the time and must be manually dis-engaged.

 

[Hammer]

Its possible that it may be a exhaust leak causing your higher pitched sound.Pressure has to go somewhere and if there is a small leak in the system or a EGR valve failing it will find that first.

 

[AllianceDiesel]

Check the rear exhaust manifold to egr cooler gasket. I have seen multiple 6.7s leaking there. And is only noticable with the exhaust brake on

 

[jkern]

Thanks for the ideas guys, i will look around the manifold and such...i doubt that the EGR has anything to do with it, that stuff fell off the truck 50k miles ago!

 

[george]

Just curious, what was the cause of the sound you were hearing?