bluesurf

thanks CD. what turbo did you upgrade to and what did you spend roughly? thanks

bluesurf

how did you adjust the pac brake when you installed it. there was no memo of this on the install sheets. first i hear of this thanks.

CTD NUT

If your Pacbrake is a PRXB, it has an internal blow off valve that is factory set and actually regulates back pressure. I have never heard of anyone messing with the factory setting.

Jeff in TD

So does the Pacbrake get it's control input from the engine computer like the Jake?

That should prevent it from coming on unless the throttle position sensor has been at 0 for like a second and a half.

CTD NUT

Yes.

You can also bypass the computer controlled brake engagement and run them manually but the throttle pedal switch used with the manual override kits still disables the brake once any amount of pedal movement is detected.

Roperteacher

I think Pac brake is an awesome product! I was not taking away from that I was just stating what happened to mine is all and I cannot afford a new turbo at this point either so it was either get it fixed under warranty or take a chance on blowing more than the turbo. Thats all. Thats what really TICKS ME off sometimes about sites like this. Someone comes on and has a question and all you get is a bunch of people saying " Mine has been on there X number of year with no problems". Well, sometimes others are so lucks anwe have problems. Some of us are not made of money and can't fork out hundreds of bucks. Like origional poster stated, same as me.

Pac brake told me they thought maybe my brake was not disengaging good enough, that it would be and ECM imcompatibility with the pac brake. Thats all I remember. THey refunded me and I didn't even ask for it.

cbrahs

make that turbos

twins baby with remote mounted brake

CTD NUT

Your experience is certainly relevant to the topic of the thread. As is ours. The thing is, we are discussing two components that have a very, very long track record of being very compatible with each other. You believe your experience is the exception to the norm....and you are right. My point was very specific in that I was wanting to know exactly what the source of your problems were as your post was very open-ended and inconclusive. Based on our collective experience as a group and industry, it is reasonable to assume that your truck had an unlying problem that was causing the failures.

As more info comes to light, it seems possible that your brake or its controls were not functioning properly. This is important to note since there are all kinds of inter-related components in our trucks where compatibility relies on the components to be functioning properly. Take that away and all bets are off.

In general, I believe my comment still stands: It is not possible for an exhaust brake to compromise the life of a turbo. Unfortunately, I left out the notion that this statement assumes both the turbo and brake were functioning properly and in good working condition.

Very few people are "made of money"....myself included. I'm no different than you or the OP in this regard. Please get past that for the sake of the thread topic. Proper diagnoses of the problem (like a simple back pressure test) may have gone a long way to avoiding multiple turbo replacements. Or, you simply got lucky that the last turbo that was installed was not a POS reman...hind sight is 20/20.

Jeff in TD

I was kind of wondering if it can close immediately if you were to go from full pedal to idle...

CTD NUT

^ No, as I recall, there is a 1.5 second programmed delay.

Jeff in TD

It must be controlled by the ECM then, since it does that. It allows you to leave the switch on while accelerating and upshifting without having the brake activate.

I think it also gives the turbo a second to spin down before the valve closes, if you were to suddenly take your foot off from full pedal. If it were set up to bypass that feature, I would think that could result in a really bad turbo bark.

CTD NUT

Yup, the ECM has an exhaust brake control funtion built in. It will completely control it. That said, I run my PRXB manually with the Pac bypass kit. I have a 6 spd and can't stand the delay and prefer manual control. I also had a Pacbrake on my 98.5 5 spd that functioned the same. I have probably 300K+ of use with manuals and exhaust brakes and can say with certainty that the turbo bark issue is only evident from being deep into the throttle and letting off abruptly - with or without the brake on...it does not matter. The brake does nothing to contribute or cause that massive and instantaneous pressure reversion on the compressor side that creates the "bark". The brake only serves to restrict flow on the turbine side and cannot create the reversion pressure spike at the compressor.