Exhaust brake smoke

[Kalaehina]

Tonight when I was on the freeway going about 60 mph, a guy cuts in front of me and brakes hard, so I get around him and get up to about 75 mph and I cut in front of him and hit my Pacbrake, I noticed alot of hazy smoke coming out when I did that, this is the second time I caught this happening today. I stopped at a light with my e-brake and noticed some smoke blow past me but didn't know where it came from. I didn't rev her up or anything so I didn't think it was form me at the time, but after seeing it happen on the freeway now I think that is what happened. Is this normal? If not, what is going on here? Is it just some soot being blown out? But if so, how is it coming out that much if my brake is on?

 

[LFarrar]

Well let's see what our expert staff here say, cause I thought I saw the same on an exit ramp the other day. I thought I was seeing things in the mirror. I hope it is not bad. I hae BD brake on mine.

 

[krs]

there was a lot of black smoke when mine stuck closed but otherwise not.

The brakes cut airflow but not fuel so maybe you're still fueling for a little even though you're off the gas?

 

[Kalaehina]

Forgot to mention, my Pacbrake does not have the "performance plug", so it is not totally blocking the exhaust, guess it could becoming through there too. Just weird to have seen that much come out as I was slowing down, kinda cool though cuz it sorta smoked that guy behind me as I slowed down, but I don't want it happening if it ain't normal. If my brake gets stuck shut, how will I know?

 

[Joe G.]

If your Pacbrake sticks you WILL know it. No power at all, smoke like a forest fire, and EGT will be really high. It won't outrun a sick VW with the Pacbrake stuck.

 

[Kalaehina]

How do you "unstuck" it? Is that what that override switch is for? Or is there another trick to it?

 

[Joe G.]

It usually sticks because the vacuum solenoid gets dirty. That's the little gadget just behind the air intake on the manifold. It has a big vacuum hose and two small vacuum hoses. Two wires. Remove it before takeing it apart because you don't want to drop any little parts on the engine.



The butterfly valve in the brake can get sooted up and stick if you don't use it once in a while. Kind of rare occurance for that.

 

[ROADWARRIOR]

I have never had a sticking problem with mine, and I too will sometimes get the haze you noticed.



Dan

 

[Boondocker]

exhaust brake haze

But I only notice it at night



I figure the combination of high RPM (much higher than idle), zero throttle and zero boost make for poor combustion - hence a little smoke.



I don't worry about it.

 

[JSHAW]

I noticed the same thing started happening today. A constant haze with the brake on and smoke when stopped. What is the easiest way to clean the pacbrake?