Poor Brake Practice and Runaway Ramps

[Ronnie]

Charlie, thanks for posting the Telma videos, great info.

[TJones]

The variable geometry turbo on the Cummins ISC can function as an exhaust brake. I have't figured out if it is enabled on mine or if I would need to add a switch and enable it in the ECM.

Ted

[MarkyDee]

My Detroit S60 + ZF tranny has an interesting combo: the tranny has the hydraulic retarder, and the engine can "turn off" 2 or 4 of the cylinders. I'm guessing the engine "turning off" 2 or 4 of the cylinders is much like the noisy jake brake, but I haven't heard the engine even when braking like that....


Unfortunately I have yet to get it out on some decent grades.

[Sleddgracer]

Originally Posted by MarkyDee

My Detroit S60 + ZF tranny has an interesting combo: the tranny has the hydraulic retarder, and the engine can "turn off" 2 or 4 of the cylinders. I'm guessing the engine "turning off" 2 or 4 of the cylinders is much like the noisy jake brake, but I haven't heard the engine even when braking like that....


Unfortunately I have yet to get it out on some decent grades.

I always thought the motors that were able to shut down some cylinders was a fuel saving feature

[MarkyDee]

Originally Posted by Sleddgracer

I always thought the motors that were able to shut down some cylinders was a fuel saving feature

Maybe it is, I'm a complete neophyte at this.... Your guess is actually better than mine. But looking at the PLC logic, it seems the PLC requests cylinders to be shut off during braking. I'll look again just to be sure.

[Sleddgracer]

Originally Posted by MarkyDee

Maybe it is, I'm a complete neophyte at this.... Your guess is actually better than mine. But looking at the PLC logic, it seems the PLC requests cylinders to be shut off during braking. I'll look again just to be sure.

that would make sense too - you don't need fuel sent to the cylinders during braking

[MarkyDee]

Heh, I saw that logic in the PLC and I just thought "cool! I don't need no stinkin' jake!"

[Dirtdoctor]

It’s simple- as a CDL driver you start down the hill in a gear lower than you climbed it in. Slow and steady. My transfer truck and trailer had a18 speed and Jake brakes. The 10 wheel with an automatic didn’t have engine braking- the automatic transmission was a huge mistake but that’s another discussion. When going downhill the automatic transmission “automatically shifted to the next higher gear because the computer just thought it was the thing to do... stickshifts won’t do that. So going slow and proper braking practices will keep you safe. I see folks driving those big ass motorhomes riding their brakes flying downhills. Zero training is unacceptable- killing people is inexcusable- take the run-away truck ramp and pay the fines. Cheers

[kidharris]

Originally Posted by turf

i have a locking transmission now and life is much easier as it helps control the downhill speed too.

Will someone please clue me on what a locking transmission is? How do I find out if mine is one?

[Brad_SwiftFur]

Originally Posted by kidharris

Will someone please clue me on what a locking transmission is? How do I find out if mine is one?

Pretty much any transmission other than the AT545.

[WARGEAR]

Originally Posted by MarkyDee

My Detroit S60 + ZF tranny has an interesting combo: the tranny has the hydraulic retarder, and the engine can "turn off" 2 or 4 of the cylinders. I'm guessing the engine "turning off" 2 or 4 of the cylinders is much like the noisy jake brake, but I haven't heard the engine even when braking like that....


Unfortunately I have yet to get it out on some decent grades.

The Series 60 in my job’s FreightShakers has the same setup. It’s an engine brake with multiple options. You can have 2, 4, or all 6 cylinders working for engine braking. It’s just different levels. Our CAT C7s have a “Hi/Low” setting for the engine brake as well.

[Sleddgracer]

learn something new every day

[Dirtdoctor]

Not all newer transmissions have “locking” capabilities.

[EastCoastCB]

Originally Posted by Dirtdoctor

Not all newer transmissions have “locking” capabilities.

Which modern school bus transmissions don't have locking torque converters?

[Kubla]

when I was driving trucks in the 80's and 90's pretty much only owner operators had jakes, I drove one truck that had a blue ox exhaust brake, which is just on-off and work ok but not as good as a jake brake

[HazMatt]

Is it worth looking to see if a T444E could be retrofitted with one of those beauts?

Originally Posted by Kubla

when I was driving trucks in the 80's and 90's pretty much only owner operators had jakes, I drove one truck that had a blue ox exhaust brake, which is just on-off and work ok but not as good as a jake brake

[ol trunt]

My Isuzu TD (in my Skoolie) has an exhaust brake controlled by the computer (manual switch as well). All it is is a block in the exhaust pipe sort of like the slice valve in a black tank drain controlled by vacuum. Short of the computer control, it would be easy to stick one of these in any vehicle. My exhaust brake opens at 30 mph--I suppose this keeps the engine from dying. This takes me back to when I was a kid and stuffed potatoes in unsuspecting motorist's tail pipes--too much fun!
Jack

[jazty]

The T444e has a butterfly valve (Exhaust Back Pressure Valve, EBPV) just after the turbo that is used to create back pressure to aid engine warm-up in cold temperatures. I've heard of people adding a manual switch to the valve for use as an exhaust brake.


https://www.ford-trucks.com/forums/1...ine-brake.html

[HazMatt]

That is just TOO freakin' cool!

Originally Posted by jazty

The T444e has a butterfly valve (Exhaust Back Pressure Valve, EBPV) just after the turbo that is used to create back pressure to aid engine warm-up in cold temperatures. I've heard of people adding a manual switch to the valve for use as an exhaust brake.


https://www.ford-trucks.com/forums/1...ine-brake.html

I have SO gots to git me one! (Mountains figure in my future)
Thanx for the link,
Bookmarked!!!

[Booyah45828]

Well, although many have done it, Ford and Navistar are both against it. Because of the hydraulic lifters used in the engine, using the ebpv as a brake in certain circumstances can cause the exhaust valves to hang open and hit the pistons.