Ever wonder what a jake brake looks like? Here's mine for your viewing pleasure.
jor
Thanks, jor.
jor,
Were you just inspecting or performing some maintenance on it? Inquiring minds would like to know.
Thanks for the pic,
Jerry aka Murph
Had the valves and injectors adjusted. Took the opportunity to snap a photo.
jor
Just for the g whizzes I thought about adding a jake to my m11.
If I run into any real serious heating issues with the retarder I know there is an alternative
Bob
Did your engine come with Jake retarder? Didn't know Foretravel had any engines with built-in retarders and thought that it takes a larger engine to work with a retarder. Does it sound off with brap brap like a truck when engaged? Does it work ok?
I have the JAKE on my 95 M11. Works GREAT!
No bells or whistle sounds on mine.
I was just talking to another 95 owner and he has a Jake too. I wonder when they changed over.
We were discussing resonators and his jake came up.
I've had all three supplementary braking systems, all of which are commonly referred to as retarders: exhaust; compression; and transmission retarder.
Foretravel installed a compression brake on many engines although the vast majority are equipped with transmission retarders. On our (and others') 95 U-300, Foretravel installed a Jake compression brake. They set it up as either a two speed Jake (3 cylinders or 6 cylinders) or a one speed (all six cylinders). Mine was a one speed and I recently had it rewired as a two speed.
Bob, re installing a Jake as a just-in-case measure, I suppose you could do so but it would probably be overkill. Our 4060 would heat up on those long 7% grades but not get anywhere near the Allison's heat limit.
Barry, regarding the brap, brap sound, no it doesn't make much noise. The large stock muffler does a good job of containing it. You can hear it but it's not offensive. No need to avoid using it when you see those "no Jake brake" signs. Incidentally, I've read that the Jake company asks users to report signs that indicate "Jake" instead of "compression brake." They say that a properly muffled Jake won't make an objectionable noise.
So, a stock Foretravel with a compression brake does not make the brap brap that you hear from a lot of semi trucks but there is one case in which it will. I'm at Foretravel right now and I met a guy here (not on the forum) who also has a 95. His is a 320 with a Jake. He related to me that he did something to his rig that I have been curious about. He removed his failing muffler and installed a resonator in its place. He got more power and better fuel consumption and a real surprise too! Right after he installed it, coming off the loop here with a retaining wall on his left side, he engaged the Jake. BRAP, BRAP, BRAP - just like a logging truck. I don't know, I think I'd kind of like it but my wife has put her foot down on this one.
So, which one is best? I don't think you can beat the transmission retarder but I find the two speed Jake with a 5th gear pre-select to be a close second and the exhaust bringing up the rear. In the end, if you can descend without white knuckles, I guess whatever system you have is doing the trick.
jor
Hey John, if you have the Brap,Brap,Brap, when you are exiting of a interstate, Judy won't have to ask if you are going to Slow Down.
I only had one customer tell me ever he overheated his retarder. 1989 u300 and he was at max gcwr and he was in Denali park in Alaska. Some giant grade. Not in lower 48 he mentioned and he tried to see if he could just to test.
I liked the jake on a 3176 in the marquis and they had a two, four and six cylinder control mod optionally available. Plus customer preference software was available to run the jake on cruise control.
At 37,000 combined pounds with a tow the 91 marquis got 8.25mpg. 65 up and down hills without touching either pedal.
All you had to do was change the number of cylinders in operation next to your left arm down hills to match the load and grade.
Only other older coach I would consider as it had webasto hot water four zone adjustable fan speed really quiet heating and peninsula insulated windows.
Turns out my u320 retarder works on cruise control and the rear brake lights do come on in operation. Could see them in the camera at night.
Going to a resonator so the jake unless one drift by is a back burner item.
The jake availability is probably why foretravel put such overkill mufflers in our coaches.
Good info. Thanks.
Bob
I have had my temps get up to 248 degrees. I did stop a while for lunch then and let it cool. I think Silverleaf will show you that the temps rise pretty fast. One location it is taken is at the sump the other is at the retarder. That has a higher allowable temp than the sump. But on long and steep grades you can heat up even if you are in third gear and stab the brakes too.
John, thanks for the enlightenment on Foretravel compression braking. Understand the brap is from releasing the compressed air at the top of the stroke, so it does not push the piston down.