Exhaust brake operation

Donstar · April 28, 2020

50 minutes ago, BLW said:

These hills can be 1/2 mile long and if im not riding the foot brake an manually activating trailer brakes id go over the cliff and even doing this front brakes were smoking like there were on fire,t

Welcome to this forum! You are towing a significant weight but well within the capabilities of your truck. I'd get my vehicle and trailer brakes checked. Your issue may be mechanical. I used to live many miles away from paved roads. At the time, I'd only drive a manual which was heavily used when long steep hills were encountered. Does the transmission in the one ton have options to hold in a lower gear?

BLW · April 28, 2020

Even in 1st gear truck just keeps gaining speed if im not standing on my brakes,trailer brakes are what saves me from cliff diving

redwngr · April 28, 2020

1 hour ago, BLW said:

Thanks for the reply my truck doesn't have hill decent option.These hills can be 1/2 mile long and if im not riding the foot brake an manually activating trailer brakes id go over the cliff and even doing this front brakes were smoking like there were on fire,truck does not hold back with exhaust brake at all.So i wonder if it works when it normally [pavement]i can hear/feel the torque converter engage.I do try using the cruise control but i must be going 40mph for it to set then manually lower it be getting to 40mph is not safe on these roads.Just to fast

FWIW, HDC (Hill Descent Control) will only work between 1 and 14 mph.

Should be able to set cruise at 25 mph or above. Of course touching the brakes disengages cruise.

Not sure why you are finding you need to be at 40 mph to set it.

Are you also using tow/haul mode?

It makes the exhaust brake more aggressive.

Are you leaving the transmission in auto?

Using manual mode prevents the exhaust brake from performing automatic downshifts to help maintain speed (but, of course in manual you can downshift it)

Exhaust brake only works when the torque converter is locked.

GM says lockup varies with speed, load and gear.

Icutmetl · April 29, 2020

On 4/28/2020 at 8:41 AM, BLW said:

Thanks for the reply my truck doesn't have hill decent option.These hills can be 1/2 mile long and if im not riding the foot brake an manually activating trailer brakes id go over the cliff and even doing this front brakes were smoking like there were on fire,truck does not hold back with exhaust brake at all.So i wonder if it works when it normally [pavement]i can hear/feel the torque converter engage.I do try using the cruise control but i must be going 40mph for it to set then manually lower it be getting to 40mph is not safe on these roads.Just to fast

A Denali doesn’t have hill decent control??

redwngr · May 3, 2020

On 4/29/2020 at 4:34 PM, Icutmetl said:

A Denali doesn’t have hill decent control??

On 2019 3500 Denali, Hill descent is 'included and only available with' Z71, and Z71 is optional.

And, Z71 is also not available with dual wheels.

SRW Denali's that have Z71 added, do not get the Z71 front emblem.

On 2020 3500 Denali JHD (Hill Descent) it is standard on SRW and not available with DRW

Edited May 3, 2020 by redwngr

Diver6 · May 3, 2020

I have a 2019 3500 Denali SRW and I don't have hill decent on mine. Also correct me if I'm wrong but I don't think the exhaust brake is at all like the "Jake brake" I think it only down shifts the trans and uses the engines compression to slow down. I think they just gave us advanced down shifting and marketed it as an "exhaust brake"

BLW · May 3, 2020

On 4/28/2020 at 8:13 AM, redwngr said:

FWIW, HDC (Hill Descent Control) will only work between 1 and 14 mph.

Should be able to set cruise at 25 mph or above. Of course touching the brakes disengages cruise.

Not sure why you are finding you need to be at 40 mph to set it.

Are you also using tow/haul mode?

It makes the exhaust brake more aggressive.

Are you leaving the transmission in auto?

Using manual mode prevents the exhaust brake from performing automatic downshifts to help maintain speed (but, of course in manual you can downshift it)

Exhaust brake only works when the torque converter is locked.

GM says lockup varies with speed, load and gear.

BLW · May 3, 2020

I use tow haul mode in auto.My torque converter will not kick in under 40 mph.i believe something is not right with this truck

Bob A1951 · August 31, 2020

I have a Chevy 3500HD diesel. I am in Colorado with a lot of steep downgrades. I pull a 17,000lb fifth wheel. I am new to all of this. I had been using the manual selection on steep downgrades......running usually in second gear. Now I just discovered I have an exhaust brake button I didn't know about. When this is engaged, and tow haul is on, do I leave the transmission in drive or still use manual to keep the truck from gaining too much speed?

newdude · August 31, 2020

On 5/3/2020 at 3:09 PM, Diver6 said:

I have a 2019 3500 Denali SRW and I don't have hill decent on mine. Also correct me if I'm wrong but I don't think the exhaust brake is at all like the "Jake brake" I think it only down shifts the trans and uses the engines compression to slow down. I think they just gave us advanced down shifting and marketed it as an "exhaust brake"

Its an exhaust brake, not an engine brake. A "Jake brake" is an engine brake, in where its mechanically closing the exhaust valves in the cylinder head.

These trucks use an exhaust brake, in there the turbocharger's VGT vanes can close up to increase exhaust pressure in the system to slow the truck down.

redwngr · September 3, 2020

On 8/31/2020 at 10:13 AM, Bob A1951 said:

I have a Chevy 3500HD diesel. I am in Colorado with a lot of steep downgrades. I pull a 17,000lb fifth wheel. I am new to all of this. I had been using the manual selection on steep downgrades......running usually in second gear. Now I just discovered I have an exhaust brake button I didn't know about. When this is engaged, and tow haul is on, do I leave the transmission in drive or still use manual to keep the truck from gaining too much speed?

Drive. It has the ability to request a downshift as necessary to maintain desired speed.

If you use M, that function will be defeated.

The exhaust brake is more active with tow/haul engaged.

It also pairs well with cruise conrol.