Anyone using any exhaust brakes?

[rids15]

Thanks for the info.

[StevenE]

Once an e-brake is installed, how does the driver activate it? I assume there is some sort of button/switch close at hand that activates the system. Also, I will be towing our new Rockwood 33' TT, about 7500# loaded. Would you recommned an E-brake for this?

[Diesel Nut]

There are 2 different ways of activating the brake, either a shifter mounted or dash mounted switch. This switch will arm the system. When you lift off the throttle the brake will engage in about 3-4 seconds, to keep from being jerky. If you step back on the throttle the brake will disengage.

Anyone towing in the hills will benefit from an Exhaust Brake.

[StevenE]

Is there any chance of engine damange?

[Diesel Nut]

No. The Brake is set to produce back pressure against the motor, but not near enough to float the exhaust valves. You aren't applying any more pressure to the motor than you do with normal driving. With turbocharged motors, you have whats called drive pressure, which is the pressure built up between the piston and the turbo wheel. This is what turns the turbo over. Every turbo has an A/R ratio, which tells you the ration of drive pressure to boost pressure. In the interest of turbo spool up and lack of smoke, most of your stock chargers are around a 2:1 due to smaller exhaust housings and wheels. So, at 30psi of boost, you make 60psi of drive pressure against the pistons. All you are doing is applying the same amount of pressure against the motor without building all that power.

[TravelswithCharly]

Originally Posted by Diesel Nut

So, at 30psi of boost, you make 60psi of drive pressure against the pistons. All you are doing is applying the same amount of pressure against the motor without building all that power.

All 2nd gen and higher dmax's have an exhaust brake from the factory: the Variable Vane Turbo. Mine is configured with EFILive such that I always have an exhaust brake at the higher non-fueled RPM's. Given that this custom tune also provides 90 towing HP, mpg benefit, lower noise, better altitude performance, nicer progressive power when empty than handhelds provide, accurate DIC, EGR defeat, wheel size speedo calibration, just to scratch the surface. a great tool.

[StevenE]

Diesel Nut ... pm sent.

Steven

[Ray,IN]

The Allison FAQ page answers the question of using an exhaust brake on the D/A combo: http://www.allisontransmission.com/s...?CategoryID=11 In short, the Ebrake must be connected to the TCM.
Frozenhosehead- a true Jake brake willl not work to warm up an engine, because it works by altering valve timing, which effectively turns a diesel engine into an air compressor working in reverse. What this discussion is about is an exhaust brake- a restriction in the exhaust system.

[2TheMaxx]

Originally Posted by 4wdcwby

i thought the chevy has grade braking.or maybe engine/tranny braking. example. when i am pulling my toyhauler at a good rate of speed or going down a grade, when i step the brake my rpm's move up alittle and i think my engine and tranny start helping me slow down. ( poss down shifting ) ??
this is not the same as exhaust braking ?????????

This is not quite the same. Your transmission is using higher rpms and shifting down to slow the vehicle an exhaust (jake) brake uses back pressure in the exhaust. Ever hear a semi let off the gas and the exhaust roars, thats the jake brake.

I have used the allisons engine grade braking towing in the mountains and it works great. If there isn't enough speed reduction from the grade braking just tap the minus button on the shifter to drop another gear. This seemed to be sufficient enough and there was no need for a jake brake. I also drive a semi and every big rig driver knows you don't use the jake brake when it is snowy or icy unless you want the trailer to pass you up. In this case you shift down to create more rpms and there is also a johnny brake on semis. It is essentially a trailer brake. This will help slow you down and keep everything in a straight line. In snowy, icy conditions and if your towing a jake brake is trouble. Any other time ,unless your hauling more than these pickups are rated to tow, the engine grade braking is suffient. If you have to tow that much weight you can buy a good used semi for half of what a new diesel pickup costs.

[TravelswithCharly]

Originally Posted by 2TheMaxx

In snowy, icy conditions a jake brake is trouble.

That is very important. Must be a manual engagement.