Smoked the brakes yesterday-update on test

Thanks Fireup.
I'm talking about Montezuma's grade dropping into Borrgo Springs. Been down it many times over the years. 1st timing smoking the brakes.
Good to know that at 25,000 miles It isn't likely that I damaged anything.
I was traveling with a 6 month old Golden Retriever. Was his first trip and I simply may have been paying more attention to him and less on what I was suppose to be doing down that hairraisng descent.
Coach is due for a new set of tires so I'll have the brakes checked out at the same time.

Dan

Dan,
First off, another San Diegan huh? Well, I was born and raised there. Lived there 'till 9 months ago, when I finally cooersed the wife to move. We're now in beautiful, Lake Havasu City AZ.

Anyway, your coach, a DP, and all of it's standard programming in the engine ECM, the Trans ECM and the PAC brake, all work together. When descending down hills, if you've "asked" for the exhaust brake, as in following all the parameters, foot off the accelerator and, Cruise control not activated, your ECM will then allow the pac brake to engage.

When it does, it decides what gear to start the descent in, based on your present speed. Normally, if you've not had it re-set, there's a target gear that it will aim for. And that is 2nd gear. That number will appear on the keypad of your trans shift, even if you're starting your descent at say 65 mph.

Ours is completely stock and has never been altered. If I start a descent at around 65 mph, and ask for the exhaust brake, it will take effect but, at that speed, it will only drop the trans to 5th. As the coach begins to slow down, either on its own, or with the assistance of the service brakes, and it reaches between 62-63 mph, the trans will drop to 4th, on it's own.

If the grade is not too steep, that is, the exhaust brake is enough to keep slowing the coach down without the use of the service brakes, it will slow to a point that the trans will downshift to 3rd, on it's own. If the grade is too steep, and it's too much for the exhaust brake to handle, I will of course have to stab at the service brakes enough to slow the coach enough to my liking for it's rate of speed in that given situation and set of driving conditions.

You're driving YOUR coach. To be told to downshift manually without being in your coach, at your speed, doing the driving that you're doing, at the present time, is really hard to do. Each situation is different and, in many cases, is constantly changing, from minute to minute, and almost second to second, based on descent rate, curves, dips, momentum, and a whole host of other variables.

If you've driven this coach for as long as you say you have and, you've been on this particular grade before, then you should know how do descend it without damaging any brakes or other components. Sure, it's possible you'll heat them up a bit, that's a given, in many situations. The exhaust brake is only so strong. It's designed to ASSIST in braking, not do the stopping.

If properly used, it will extend the life of the service brakes by many thousands of miles. Most D/P units that are equipped with either an exhaust brake or, a true Jake Brake (compression style), should see over 100,000 miles on the odometer BEFORE ever needing to touch the service brakes, for brake service that is. This of course does not include leaky seals which, could cause enough saturation of brake shoes do warrant discard prematurely.

But, in your case, as Brett Wolf told you, the "ONE TIME" issue with the stuck emergency brakes is a non-issue with your present situation. It happens to a lot of folks in that situation. It has no effect on wear and, for the most part, have no effect on regular braking.

But, if you "warmed" them up a bit and, generally have not done it before, then it might warrant at the very least, a good, "remove the tires and wheels," brake and drum (if those are the types you have) inspection. I've done that type of inspection on mine, several times. In the pics below, you'll see shoes that have gotten pretty warm descending some serious grades. And, as you can see, there's certainly no warrant for replacement. Good luck and, do pay more ATTENTION while on those grades.
Scott

X2 Dan!!

Dan,

Thank you for your service to our country. The Viet Nam vets did not get appropriate recognition for serving.

Do you think you could have been dragging the breaks by resting you foot on the break pedal. Just thinking of all possibilities.

DanLefoot wrote:

Terryallan wrote:
IF the trany won't automatically drop to lower a lower gear. You have to do it manually. The lower the gear, the better the exhaust brake works. Not so much in higher gears

I get it now. On the 8% part of the grade I would brake hard and long enough to bring the speed down low enough so the auto tranny dropped into 2nd gear. But after a quarter of a mile or so the grade would lessen to 4%. My foot goes the accelerator which releases the exhaust brake and shifts to 6 gear. And not too long after I hit another 8% grade and I have to hit the brakes again and so on.
I think operator error.

Look at your transmission readout going up the hill and see what gear the trans is using to lug you up. Generally speaking use that same gear going down the other side - you will have to manually select the gear using the pad. Other wise you will be riding the brakes. If it seems to speed up after taking foot off the gas on the down slope you need a lower gear that will slow you down without the brake or keep you at a steady speed. If anything you should only need to stab the brakes once in a while if the trans and exhaust brake aren't enough.

L2R wrote:
A lot of irony here, having a brake issue with your last name being Lafoote!

Good luck

Well, not my real name.
I lost a leg in Vietnam In 1969. I was on an all expenses paid trip by the U.S. Government. Sometimes I can't help myself

Terryallan wrote:
IF the trany won't automatically drop to lower a lower gear. You have to do it manually. The lower the gear, the better the exhaust brake works. Not so much in higher gears

I get it now. On the 8% part of the grade I would brake hard and long enough to bring the speed down low enough so the auto tranny dropped into 2nd gear. But after a quarter of a mile or so the grade would lessen to 4%. My foot goes the accelerator which releases the exhaust brake and shifts to 6 gear. And not too long after I hit another 8% grade and I have to hit the brakes again and so on.
I think operator error.

ccxnola wrote:
On long downhill grades, I ALWAYS use the lower gears in the Allison.
During the annual check last year, the mechanic asked if I even used the brakes - there was so little wear. Yes, I drop gears leaving the Interstate, approaching a stop light or any time I need to slow down.
Sure, the dashboard controller gets punched a lot, but it has worked for me.

You think after almost 15 years with a DP I would have known that. I never, ever have used anything but drive, reverse and N. I usually run with the exhaust brake on. And haven't had a problem till now. Hopefully I haven't toasted the brakes
I'll give it a try.

Agree with downshifting. You need to keep the RPM up near redline for max braking.