Exhaust brake on a idi

[burt]

I vaguely remember a while back that I heard exhaust brakes and idi were a bad combo. I really want this to be bs. Is an exhaust brake bad for an idi in particular and if so how bad and in what way. I'd be willing to use it sparingly if its just mildly bad. The exhaust brake that I have is a us gear one that came on my 93 crew cab. I got the truck with around 185,000 and it made it to probably 220,000 before it needed a new motor. The original owner is who I got it from and he said he put the banks sidewinder (waste gated) and exhaust brake on pretty soon after he got it. Have no idea how he drove or how much he used the ex brake but 220,000 mi isn't the worst run ever. Anyone have any insight on the subject? Thanks

 

[kc0stp]

So long as adjusted correctly no harm in an exhaust brake

 

[burt]

I'm not sure it's adjustable, but if it is what should I look for in a proper adjustment? I don't have any gauges associated with it nor do I know what I would be monitoring. Any info would be appreciated. We have some long steep grades around here that almost require low range while descending w/o an ex brake with a heavy trailer. One in particular has vehicles at the bottom of it with their brakes on fire with some regularity.

 

[Wood]

whoa thats weird, i live in Redding CA just got my 92 idi with a banks and us gear exhaust brake.

and as for having any issues, snap a couple pics, there is an old and new style, new style has a bypass/pressure regulator that actually helps in lower RPMS. i love my brake.

what do you do here in redding? I sell paint @ Cascade Paint.

 

[Wood]

buckhorn summit on our brakes = no good.

burt im not sure what you could check with gauges either. my dad seems to think they are harmless if used correctly, and hes an engine builder.

 

[jaluhn83]

Nothing wrong with an exhaust brake on an IDI. The only way it could cause damage is the high exhaust pressure overpowering the valve spring and holding the valves open. The US Gear style units have a wastegate setup so you just have to make sure you've got the right one (they have a 35 psi & 50 psi, 35 psi is recommended for the idi). Other brakes generally have a small hole through the flapper to regulate pressure.

I've had a US Gear unit for some years and never had any problems with it. I just tore the engine apart after 30-40k miles of use with the brake and saw no evidence of damage. (rebuild due to an unrelated problem)
~John

 

[burt]

Thanks for the responses. I'm over the hill in humboldt now actually which is even worse with the long, no relief grades. I guess the us gear and sidewinder combo was a pretty popular set of upgrades for these trucks. Is yours an f250 or 350? Any tips on using it correctly. I'll get some pics later to see if you recognize it

 

[Garbage_Mechan]

I have a US Gear brake I havent put on yet. I have done some research on any issues, and the bypass that resembles a turbo wastegate is definitly a big plus. There are tapped holes in the brake body to put a backpressure gauge on, but the limit of our engines I don't have a number for. I would think the 35# number quoted would be a max. It isn't that big a job to put better valve springs in (Comp 910"s?) to be sure there is never an issue. Since US Gear is a dead brand (no support) I was going to look into the info for the PacBrake PBXT which works similar to the US Gear.

Thanks for the responses. I'm over the hill in humboldt now actually which is even worse with the long, no relief grades. I guess the us gear and sidewinder combo was a pretty popular set of upgrades for these trucks. Is yours an f250 or 350? Any tips on using it correctly. I'll get some pics later to see if you recognize it

 

[Garbage_Mechan]

The PacBrake is PRXB. Nothing useful on their site as to max backpressure. They do not list it for the IDI however no reason it wouldn't work. Their phone number is 800 663 0096. Need to call and jaw with them.

 

[Garbage_Mechan]

http://www.pacbrake.com/PDF/L5160.PDF

Sneaking up on it, reference to using a gauge to check and set BP but no ###

 

[Garbage_Mechan]

This set of PacBrake instructions has a little bit on putting a throttle switch on a mechanical engine, and restated the 35# backpressure on the Powerstroke. Good general reading. The only real difference between the US Gear and Pac is that USG has a pull in / hold in coil setup all electrical, and Pac is air.

These instructions are for the earlier non regulated Pac BRake not the PXRB

http://www.pacbrake.com/PDF/L2031.PDF

 

[OLDBULL8]

You should specify what transmission you have, it's relevant to exhaust braking. An E4OD tranny (year specific) would have to have the TC lockup mod to be effective down to 40 MPH unless down shifted to a lower gear to achieve higher RPM's. A worn out engine (low compression) reduces the exhaust braking effect. On a 7-8% downgrade, a downshift should be made depending on load, if braking is necessary, never let up on the brakes all the way, on/off braking allows air (oxigen) between pads and rotors. Just my opinion/thoughts. Experience was when I lost my 5er brakes in the Yukon on a 8% grade, 85 MPH at the bottom, burned up pads and rotors, front and rear. Damn permafrost, gravel road broke the brake wires. This was on my 99 with the lockup mod on the 4R100 tranny.

 

[burt]

Very interesting about not letting up on the brakes. I do just the opposite to let them cool. What's the logic on not wanting oxygen in there. Not arguing, just trying to learn something. My truck is a zf5 and I should have good compression, it's a fairly recent promar rebuild (better be good). The exhaust brake works great, I just have been using it sparingly because of this vague recollection that it may be bad. What are the consequences of floating a valve, like can I limp home to fix or will the truck be sent directly to the wreckers afterward. I've heard it said that you could float a valve but never anyone who had had that happen. Thanks for the responses, I'm thrilled that I didn't get told that it was very bad

 

[justinray]

The not letting completely off brakes is a very intelligent move when the load is puhing you downhill, because if you let air in, you may not be able to get it out in time, this sent me screaming 90+mph down mt nebo once. Which was NO fun; when the brakes finally grabbed, I had bailed off to the big truck runoff, which I feel was a smart move on my part.

This was me in my '94 f250 351w all stock pulling my buddies '82 GMC 2500 4X4 6.2l on a 20' all Iron car hauler.

 

[burt]

So would this technique only be used if A) your electric trailer brakes stopped working B) you were having trouble getting surge brakes to apply enough braking because of some particular circumstance C) were starting to boil your fluid D) brakes were starting to catch fire E) as a normal towing down a grade technique or F) all of the above? I'm pretty experienced at towing more than a safe load on roads that aren't safe for anyone but, dragging brakes down a long grade is not something I would experiment with unless I really understood what the logic is. If its an emergency technique I'd like to have it well understood so I used it properly when every second counts. I'd like to think that I know better now than to over do it with the brakes on these rigs but the more knowledge the better. Thanks for the advice even if it is off the topic of exhaust brakes.