How do I use my exhaust brake?

[vnapple]

I just had a Jacobs exhaust brake installed on my truck, so now I'd like to know how to use it. Do I just energize it while I am hooked-up, or do I turn it on/off as I need it? I can see leaving it on while on the highway, but leaving it on at idle in the city doesn't seem to make much sense.



Thanks in advance,

Vinny



'03 2500 QC, SB, 5. 9 HO, NV5600, NV273, 3. 73, JACOBS E-BRAKE

 

[jtwcummins]

Leave it on all the time you are towing. Doesn't hurt at idle since it is turned off effectivly. Mine is on ALL the time

 

[Joe G.]

leaving it on at idle in the city doesn't seem to make much sense.

Yes it does because it keeps your EGT up so that fuel burns right. I turn mine on when I start my truck and don't turn it off until I shut down.

 

[cwsoules]

When towing mine is on all the time. When not towing I turn it on occasionally to exercise it for a few minutes.

 

[DHayden]

I turn mine on to warm up the truck or if I'm going to idle more than a few minutes. I don't leave it on all the time just because I like to coast around town. I have a knob on the gear shift to actuate though so it's easy when I need it.

 

[Blu-meanie]

Use it all the time or it will stick sometime at the most inopportune time. They need to be exercised every time you drive the truck.

 

[vnapple]

Thanks, fellas, now I know.

 

[PC12Driver]

I only turn mine on when I need it. My switch is a finger's reach away on the gearshift, so I just click it on and off as needed. No sense dragging the turbo down if I'm just gonna coast for a bit. And I don't idle enough around town to worry about incomplete combustion due to low temps, so I'd prefer not to waste fuel with it on at every stoplight.



I use it for warm up in the cooler months, but only to get it to 100-120* and then I start driving. Idleing with the brake on will push some of the exhaust back into the intake (valve overlap - when both the intake and the exhaust valves are open at the same time) and will foul the MAP and IAT sensors with soot. Ever since I pulled mine out and saw how bad they were I've kept my e-brake idleing to a minimum.



Downshifting with the brake on is harder on the clutch. There are springs in the clutch hub that will absorb shocks in the drive direction, but there's not much dampening in the coast direction. Plus you'll get more wear on the clutch when you let it back out. I'll click mine off or blip the throttle when I downshift.



I do use it pretty much every time I slow to a stop from 40mph or above. I'll downshift to fifth and click it on, and then click it off below 1100-1200rpm or so where you're not really getting any braking. I may downshift once more depending on load, but that's about it. And I really don't use it around town since the rpm's aren't usually high enough to do anything anyway except make noise.



That's good advice to cycle it whenever you drive it to keep it free.



Notice that all the guys that suggest leaving it on have autos?

 

[jtwcummins]

That's because the controller turns on brake until coolant temp hits 130* then it is turned off. This happens automatically even if the brake is off. The brake also disengages when the speed drops below 22mph w/od on and 18 with od off. So leaving it on all the time with an auto is not an issue.

 

[WestTN]

I have been working on an electronic circuit to cut it off below 20 mph. I have been only partially successful so far. I figured out how to use the vehicle speed sensor input from the Antilock Brake Controller. I'm still working on the signal conditioning and switching end of it.

 

[GerryDrake]

Ditto

I only turn mine on when I need it. My switch is a finger's reach away on the gearshift, so I just click it on and off as needed. No sense dragging the turbo down if I'm just gonna coast for a bit. And I don't idle enough around town to worry about incomplete combustion due to low temps, so I'd prefer not to waste fuel with it on at every stoplight.



I use it for warm up in the cooler months, but only to get it to 100-120* and then I start driving. Idleing with the brake on will push some of the exhaust back into the intake (valve overlap - when both the intake and the exhaust valves are open at the same time) and will foul the MAP and IAT sensors with soot. Ever since I pulled mine out and saw how bad they were I've kept my e-brake idleing to a minimum.



Downshifting with the brake on is harder on the clutch. There are springs in the clutch hub that will absorb shocks in the drive direction, but there's not much dampening in the coast direction. Plus you'll get more wear on the clutch when you let it back out. I'll click mine off or blip the throttle when I downshift.



I do use it pretty much every time I slow to a stop from 40mph or above. I'll downshift to fifth and click it on, and then click it off below 1100-1200rpm or so where you're not really getting any braking. I may downshift once more depending on load, but that's about it. And I really don't use it around town since the rpm's aren't usually high enough to do anything anyway except make noise.



That's good advice to cycle it whenever you drive it to keep it free.



Notice that all the guys that suggest leaving it on have autos?

This very closely describes my use, with the added aspect that if we are just tooling down the freeway or major road I leave it off unless traffic is getting thick. No point to my mind in the additional slowing when you just barely slow with traffic. Off ramps or gentle up and down hills, it is on most of the time. .

 

[PC12Driver]

That's because the controller turns on brake until coolant temp hits 130* then it is turned off. This happens automatically even if the brake is off. The brake also disengages when the speed drops below 22mph w/od on and 18 with od off. So leaving it on all the time with an auto is not an issue.

Is that a function of the '03 ECM that Vinny has or your Banks setup?



Since Vinny asked the question about how to use the ex-brake on his manual transmission truck and the first three responses were from auto owners, I wanted to point out that there would probably be operational differences between the two types of trannys.

 

[DjFire07]

I have a cole-hersee switch (usually used for a split rear) mounted to my gearshift lever. It was a very simple wiring routing and connection. I always use my jake brake for deceleration , then just flip the switch as I stop. I don't even think about it anymore. BTW, I'm still on original brakes at 87000 miles (no heavy towing).



DJ

 

[GWBourne]

i have a 6 speed and the only time mine is turned off is when im at a drive through and it is still in warm up mode OR its slick conditions out. towing empty highway or twon i use it at all times. my service brakes look GREAt at 17k miles.

Grant

 

[vnapple]

Great responses! I have a much better idea of how to use my brake now, so thanks to all. I have had this truck for about a month now, and I can't get enough of it. This is my first diesel, and I don't think I'll ever own anything else from now on.



Vinny

'03 2500 QC, SB, 5. 9 HO, NV5600, NV273, 3. 73, JACOBS E-BRAKE

 

[jtwcummins]

It's the banks smartlock that controls the brake. Monitors the speed sensor, tps, ECT, and OD on/off switch. When the accelerator is pressed the brake turns off even when warming up. I wouldn't have done the brake w/o this kind of control. I thought the Jacob's unit did much the same thing for autos or manuals even though it isn't recommended for autos. My Ebrake has been turned on for over 3 years and when getting off the freeway it really saves brakes. In slow traffic around town it doesn't do alot, but no problem leaving it on.

For your first diesel you can't beat the driveablility of the CTD. I picked truck up 1/97 and it was very driveable at 160hp/420 ftlbs, Calif EGR drops 20hp and 20 lbs torque, with the Banks it is many times better. Have more toys but will not install until transmission gets the DTT treatment. 47re has not been any problem yet. Overall this is one of the best vehicles I have owned. No problems with anything. When brakes were needed went to EGR's setup. Starting is an option and stopping is mandatory so was worth the bucks.

Reading the TDR has also kept me from reinventing the wheel and kept me knowledgeable about the truck and CTD. I have always been MOPAR, don't even consider Ford and not a big Chevy fan. Liked the 60's muscle cars and drove most of them when they were new.

 

[EricBu12]

Vinny,



Now you need to get a TT to exercise that cummins and the brake... I have a 36' 5th and I am at 23K total.