Is there any reason I shouldn't use the jake all the time? I don't tow all the time, and have to use the truck as a daily driver .

The manual for the Jake and owners manual does not mention anything for or against using it.

TIA

Tony

 

From all the information I have gathered, it is ok to use all the time, However the ECM keeps it from working below I think 25mph... Someone else will chime in with the absolute correct MPH

 

The Jake brake from the dealer will automatically shut off when three things happen, 1) engine rpm reaces idle speed 2) vehicle is stopped 3) engine temp is above 175*F.

So you can turn it on in the morning to warm up the truck which in turn will activate high idle, then when the temp reaches 175 it will shut itself off.

Drive all around town with it on and it will shut itself off at every stop. You won't ever have to turn it off if you don't want to.

On edit, don't forget to turn it off when driving in snow or ice conditions, because it could lock up the rear tires momentarily and cause you to lose control.

................Jim

 

Mine cuts off @20 mph, I leave it on.

 

Thanks for the replies.

What I have found so far....
1) Yes, it will disengage: at ~22MPH, turn the switch off, or stop too fast for it to engage.
2) The Jake won't engage, if you are easy on the throttle and don't exceed 30MPH. Once you get past 30MPH at any throttle, it will engage
3) Yes, it will engage on a cold engine when it is at idle.

I just got the hi idle enable yesterday & have not checked operation with the jake.

Tony

 

Exhaust brake.. no jake on the little 5.9

 

Your point is taken regarding the difference between exhaust and engine brakes, but be aware that the Jacobs exhaust brake on my truck came with a "Jake Brake" decal in the box - they're taking advantage of the recognition of the Jacobs name and applying it across their exhaust brake products.

Rusty

 

Yeah...What Rusty said

I have confirmed that the jake will operate up to 1000rpm; go over & it'll open up the 'exhaust brake'.

Tony

 

My early 3rd gen the exhaust brake always is on. Mine also stays on below 20 mph (a software glitch that was fixed later in the year) Mine won't shutoff when cold idleing either.

 

I think maybe the 20mph thing is related to the automatics. Both my trucks are 6spds and the Jake doesn't shutoff below any given speed. Although my 99 won't shutoff at a stop either.

.................Jim

 

Ahhh mebbe.....

Does the exhaust brake on the autos work the same as the engine brakes on the heavy trucks with the Eaton autoshifts? Automatically disengages, changes gear, the reengages? Repeats this process until you are stopped?

 

According to Tomeygun's test drive it does...

 

It will downshift from 4th to third autoatically...You CAN manually downshift into 2nd about 25-30 and the jake will still be engaged, but by 20mph, it disengages.

So....my original question....Is there any reason to turn off the brake for empty daily driving?

Thanks!

TOny

 

With the Jake on, the auto transmission shifts points are at higher rpm's. The different shift points may not give you the best fuel mileage when driving empty.

 

Cool.