Yesterday I went out an bought a used Jake brake which I removed. I will get a rebuild kit for it before I install it.
Be sure to post the installation and other parts needed to do the job. I might be interested in adding one also.
Is the retarder not enough? Just wondering
If you travel a lot of steep grades all the time, the Jake could take off some of the tranny heat. My retarder does work great, but I have to keep the coach geared down and rpm up to keep the transmission cool. My '96 Monaco with the 2 stage Jake did the same grades one gear higher and no trans temp issues.
I'm not answering for OldGuy, but from reading his prior posts, I suspect he has several good logical reasons for wanting to add a Jake.
The "value" of different aux braking devices has been discussed here in the past. They all help - some more than others.
I thought the thread linked below contained some informative and enlightening posts.
Jake Brake vs PAC Brake vs Retarder? (https://www.foreforums.com/index.php?topic=16217)
When driving last winter the retarder was awesome but those same hills I went roaring down, in the summer I would over heat.
I really like the idea of having both. Putting in a Jake brake was always in my plan if I got a Foretavel. Craneman, hopefully I won't
need to much stuff. I know I will need a floor switch as I like to be in control. I don't want it working off my throttle.
That's how my Monaco was set up jake pedal left of the steering column.
You could put in a floor switch but ours comes on whenever you lift the throttle. I didn't even notice it from the first time we had it switched on and let off on the throttle. At low rpm, you don't feel any effect. It's only at higher rpm that it comes into it's own. It's a very subtle thing. As you know I hate automatic transmissions and don't even like the HWH but the Jake is outstanding. Or I would not leave it switched on all the time.
Unless you have the window open and next to a wall or in a tunnel, you can't hear any extra noise. When in a tunnel, I always leave the window open so I can listen to the Detroit exhaust with the Jake the frosting on the cake.
Foretravel also put it on the CAT in the 1995 U300.
Pierce
When it comes to stopping more is always better. Look forward to its completion. Every heavy duty truck uses them. To me that means there cheap and work well. This has always been a back burner Idea. Really looking to see more.
Three types of People in the world.
People who make thinks happen
People Who watch things happen
People who wonder what happened
Scott
Not saying more is not better but there is initial cost, maintenance, long grade, hot weather stopping power and possible owner mismanagement on slippery roads. Pros and Cons can be argued forever but remember, the service brakes are the primary method of slowing the vehicle. Best retarder, Jake or PAC brake won't make up for a poor operator technique.
Pierce
Oldguy what exhaust does your coach have?
I have the stock exhaust, but I would still want one if I have a resonator. I don't plan on using it in towns, I have a retarder for town.
I had a foot switch for the exhaust brake in my last coach and I really like it. Going down hills to hold my speed I don't want to use my brakes. I use the brakes for stopping. In my old coach the steepest I drove was 17 percent and in low gear with the exhaust brake
it held so I didn't have to use the brakes.
Had a Custom build KW T300 set up as an RV tow 15 years ago biggest cat I could order through a 9 speed manual tranny with a jake brake.
The jake brake is so much better for long downhills, keep your foot off the brake, change down gears and the jake will be noisy and keep your speed down.
The retarder is nice when a little slowing is needed, it raises the transmission temp very quickly rendering it useless, I like the retarder but it's not substitute for a jake brake in mountain driving.
We all have different driving styles, every one to his own,
The m11 engine downshifted helps the retarder somewhat more in keeping the trans temps down in the hills. Also not being unnecessarily concerned about mid 230's on the VPMS trans temp gauge for short stretches while in use.
The Meritor disk brakes are cold blooded if not recently used and warmed up.
So if you need a panic stop the retarder is a much quicker stopping force.
I rebuilt the Meritors back to new condition which greatly helped my confidence in their heat absorption abilities after testing.
I do not use brakes on my towed so that factors in. I should be so far no issues.
Without the 3,600 pound tow the retarder and service brakes easily handle my normal hills.
Bob
When you say bring them back to new, what does that involve? Is it cleaning or new parts?
My brakes are good, but brakes can always be better!
David
New pads. New pins. New rotors. Added retraction pins. Correct grease bled off correctly.
Big time smoke first hard ride. Seat the pads. Smells. Bedded in, much better action and capacity in my experience.
Like new when I drove these back then
I assume "Added retraction pins" is the auxiliary springs that aid on retraction.
Yes
I have seen some mention of exhaust valve springs and jake brakes.
Exhaust brakes (PacBrake) on Dodge PUs. Quote:
Keep your rpm under 3500 and you won't have to worry about floating a valve with stock valve springs. Above 3500rpm and or use of an exhaust brake= the need for 60lb valve springs. Exhaust brake - just exhaust side. 3500rpm and above, both intake and exhaust sides. Pierce
Today I got the valve crossheads change, the injector adjusting screws changed and the valves adjusted. They were all too tight.
Then I finish off installing the jake spacer.
That is a common thing on the engine after 50 or 60K and needs to be checked on a lot of coaches. Sounds like you are progressing nicely and should be finished pretty quick with what you have gotten done up to this point.
Mike
Finished the mechanical side of installing the Jake. Now comes the wiring which will take quite a bit
of figgering out. One thing I need to know is my engine M11 celect or M11 plus celect. I will want
to operate from a foot peddle. I don't mind if it would work on cruise automatically, but out of cruise
I need to be in control. Then I will have to take it to Cummins to program the computor.
Call Cummins with your engine SN: Cummins 800-286-6467
A '99 is an ISM.
Celect plus ended in 1997
Cummins M-series engine - Wikipedia (https://en.wikipedia.org/wiki/Cummins_M-series_engine)
Nope. My '99 is a Celect Plus.
I am going to call Cummins today, I need to make sure of the wiring and talk about getting the computer set up.
Post the model of your engine after you speak to them. If you have an old stock '97 engine it would be a select plus. I don't know how far in advance Foretravel was stocking engines.
I talked to Cummins this afternoon. My engine is a Plus Celect M11. It looks like I just have to wire it up and it should be good to go.
If I want the Jake to work automatically on cruise I might have to go in. While I was checking the engine out yesterday I noticed the
Tac wasn't working but it was on the Silver Leaf. I also today welded a crack on the engine oil fill tube. It has been welded before
so when I put it back tomorrow I will see it I can install a brace.
Looking for wires going to the back. I have 4 right at the rear of the coach that aren't being used but EX4 2088 wire must be broken
as there is no continuity. Wires EX1, EX2, EX3 and EX4 38492 they are with 2088 wires under the dash does anyone know where they go.
Thanks to Craneman he sent me a message to check my book and the 38492 go up to the TV. The book also states that 3 wires
go up to the middle dash from the EUC. Now it I could only find them. The EUC has written on it Celect Plus. Working around
the EUC and figgering out wires from that, is going to be harder than installing the Jake.
Well I have been working on figgering out how to wire the ECU for the Jake Brake. The 2 wires going the the Jake is real easy. Just had to plug it in and the wires going to the switches I think I know how. As I'm going out to Cummins to pick up some female clips
to attach the wires to the ECU the service tech said he will make sure I get it wright. We have a really good service tech here. He knows
his stuff. I also ordered a foot peddle from Amazon so I will be able to run manually or have it come on when the throttle is released
which will work that way on cruise.
Got the wiring done at the ECU today. Picked up wire clips for the ECU and hooked up two of the extra wires from the rear of the
coach. The third wire I need goes from the ECU to the IPX Master wiper controller which is a common ground. So the rear of the
coach is done and all wires are run. The foot peddle has come and I will wire it parallel to the on/off Jake switch. So when the
switch is on it will work automatically and when the switch is off it will work manually from the floor switch. I just have install all the
switches and hook up the wires and its done.
Finished the wiring today. The switches are really handy. The selector switch is a 3 position switch but only 2 work. A a M11 is
has only 3 cylinders or 6 cylinders. That was the switch that was in the truck the the Jake came from. The foot switch isn't screwed
down yet. I will drive it before so I know were it works the best. I will tile it some day to match the floor. I will post after I drive
how it works. That will be a few weeks away. Tomorrow start another project.
Old Guy (that could apply to most of us),
Our Jake switch also has three positions, OFF, 3 cylinders or all 6 cylinders. I just keep it on the 6 cyl position. Your engine is 2 liters larger than ours so you may get a bigger benefit from the 3 cylinder position.
Pierce
Major difference in engine braking I would think between a 552 inch v6 2 stroke and a 659 inch inline 6 four stroke engine.
But we don't live down in "Shaky Town" where it's so flat a tsunami would flood all the way to Vegas. We don't have a flat spot for 60 miles until we get to Sacramento. Our little 9 liter with toad does great with the Jake. Could not ask for more.
But, an 11 liter 4 cycle engine would allow a heavier coach and toad to go on the same roads so I have to grudgingly agree.
Just a case of North vs South. :D :D
Pierce
Seems on the jake the bigger the torque the more the retardation?
The Detroit 2 cycles unlike a 2 stroke motorcycle are torque kings at low RPM. It's mostly cubic inches that determine the amount of Jake breaking the engine has.
In a gasoline car, it's vacuum that slows the vehicle. With a diesel it's the compression that does the trick. As the piston comes up to the top of the compression stroke, an actuator opens the exhaust valve(s) just before TDC and the high pressure in the cylinder is released so all the work done by compressing the air goes into a braking effect. The bigger the displacement and the higher the RPM, the more braking you get from a Jake. With a 2 stroke diesel, the Jake gets to take advantage of the engine compression on each stroke. With a 4 stroke, every other stroke. I would be interesting to put two engines of the same displacement with one a two stroke and the other a four stroke and see which one developed the more braking effect.
Better than my explanation: http://www.svfd.net/SVFD%20Files/Articles/Engineer/An%20engine%20brake%20is%20a%20hydraulically-operated%20device%20on%20a%20diesel.pdf
Pierce
My experience back in the 70's hauling lumber in PNW with 80,000lbs. 1st. trucks I could afford had 2 stroke Detroit's ~~ 8v71@318h.p. & 8v92@435 later years 4 stroke Cummins ntc400 & Cat 3406@425, hands down the 4 stroke inline 6's had more braking affect than 2 strokes. Granite the inline-6's were 14 liter vs 12 and smaller on the V's.
Well I've finally got to try out the Jake Brake. At around 1300 RPM it feels like an exhaust brake and when I shift down and the
RPM goes up it really pulls the coach down. It will be awhile before I get to try it on big long hills.
When you finally got to try it out was that using three or six cylinder position. Really looking forward to a review once you have operated it on some larger downhills. Total hours install estimate, and a ball park cost to perform installation. More is always better when it comes to stopping. What a great addition to your coach. IMO
Scott
It took me around 5 hours to remove it from the old truck and I know putting it in the coach was way easier. I did it by myself but
if you had a partner for setting the valve, injectors and the Jake that part would take 1/4 of the time. 2 wires need to be added to
the ECU so I went to Cummins for the wire pigtails ( part # 3822919). The pigtails go into the EUC plug and the Jake wiring is right
where its needed. Then I had to find 3 wires to go up to the dash. I could have probably could have got away with 2 as it is a
common ground, but you can never have to much ground and the other 2 go to the on and off switch and the other when to
the switch that give 3 or 6 cylinders. The foot peddle goes on the incoming side of the on off switch. If I did it again it would be a
lot quicker. The actual time it took was probably 8 hours.
Also I never had to go to Cummins to have it set up which made me happy. The trip so far there hasn't been any hills.
Again a great addition to your coach. I think it will make the end of my long list, but I definitely like it. Was getting a doner truck Difficult to find? Any idea what a ballpark cost would be?
Scott
I know when I was looking Vander Haag's had them on for $1890.00. I bought mine for $2000.00 Canadian which I found through
Craigs List. I didn't mine removing it as I learned a lot from taking the old on out. I took the switches so the only thing I had
to buy was the 2 connectors for the EUC. I think they were $12 each. I had been looking for about 6 months. I wanted to find the
Jake in Canada to save on import charges.
Been thinking about adding a jake for a long time. Thanks for your post.
On second thought I probably would just go faster down grades.
I like the part about really pulling the coach down at revs.
Do you have stock exhaust?
A retarder and a Jake. Now that's what I call a sweet setup. On our last rig we had a one stage Jake which I changed to a two stage. I found the 3 cylinder setting going down those looong but not too steep hills was perfect. Now you just need to add hydraulic jacks to complement your air leveling system!
jor
I don't ever remember turning our Jake off. Noise with the stock muffler is fine anywhere.
Pierce
Our retarder does not have the joystick,only the rocker switch,works great,have never seen temps higher then 205,never up to 210
and that's to Alaska and back,from what Iv'e seen on the forum the ones with the joystick get hotter,and yes the gauge is reading right.On the jake,if you have a few thou to spend then go ahead,one thing for sure it's not going to make you engine last longer by
any means and you can't compare them to the big rigs because they carry alot more weight and need all the stopping power they can get,guess what I'm saying is for me with my engine and coach the retarder works great for my use.
I have a stock muffler and I can hardly hear it. Jor before I got this coach I wanted to do hydraulic leveling jacks but I think it would
just be too much work and I probably only use them to jack up the coach to work on it. The air leveling works great and if I can't
get it level I have a residential fridge so it won't be important.
Well I went to Gold River and it has lots of corners. The Jake break quit for that trip so I had to slow down so not to cook the
retarder. Coming down Island it started to work again so the retarder temp did not climb. In cruise it seems to work if I have the
switch on but the roads I was on are mostly flat at so I didn't to check it out much. Maybe next trip.
Just got home after a week in June Lake in the Sierras. Lots of grades but the Jake kept my foot off the brakes except for a few times. Don't think I've turned the switch off since we bought it 12 years ago. What a great invention. History: Jacobs Vehicle Systems - Wikipedia (https://en.wikipedia.org/wiki/Jacobs_Vehicle_Systems)
Pierce
I went to Whistler Sunday night and Monday morning so I got to try out the Jake Brake a quite bit. It was in the three cylinder
position which was adequate. When I apply the Jake brake I have to manual shift it down and I would like to put in another
foot switch which will tell the transmission to call for 2nd gear so I won't have to manually shift the trans down. This way I would have
3 choices, one would be foot off throttle, one would be push switch and have to manually switch down and one would be push other.
switch and trans would automatically shit down. I sure like having both. This morning driving down a hill I use the retarder as there
was snow on the road and it is easier to control.
Does a Jake brake perform best at high engine RPM?
The higher the RPM the better it works the same as an exhaust brake.
Does anyone know were the trans computer is located and does anyone know how to wire it so it would get the signal to shift
down.
As the "old guy" says, the higher the RPM, the better it works. I leave it in all cylinder position all of the time. When I need less Jake, I just shift into a higher gear. The Allison leaves a lot to be desired in second and second lockup heading downgrade. Never know what it's going to do. Sometimes it just coasts along picking up speed like it's in neutral and then suddenly grabs a gear. . I usually stop at the top of a steep hill and then go through the lower gears.
Pierce
When I had a Monaco Dynasty with an exhaust brake it would call for 2nd gear and it would shift down to second without a miss
according to the RPM.
Did you have second and second lockup? If I'm slowing, there is no problem selecting and getting the right gear. The problem comes when starting downhill without any throttle.
P
I don't know how a Jake acts with an automatic transmission, but we have a term out here called a "flat land jake"
When a stick shift is accelerated with the Jake on it causes the motor to drop revs much quicker than normal allowing for faster shifts. Oh yes and it makes a hell of a racket.
The Allison ECU on our coach is mounted on the firewall under the dash in front of the driver seat. Don't know if the same on your newer coach.
Reprogramming the ECU must be done at an Allison shop. The photos below show my ECU when I removed it to send it in for repair. You can see the sticker that indicates when it was reprogrammed for the original owner of the coach (same time he had the exhaust brake installed).
Any Jake with an automatic transmission I've driven does not activate until your foot is totally off the accelerator. Then, just before the vehicle stops, the Jake disengages automatically. The 2 cycles don't make nearly as much noise but not quite as effective as in a 4 cycle.
You must be saying that when you accelerate with a manual gearbox and go to shift to the next gear, the RPM drops faster that when the Jake is turned off. That would make a much faster shift with a crash box. Excellent.
Pierce
This is my second trip to Whistler with the Jake. Last week going home it quit and then going down the longest hill, I was just goin to
apply the retarder and it came on. It worked all the way down the hill and I switched it between 3 and 6 cylinders and then it quit for
the rest of the trip. Over the weekend I checked the plug that is up by the valve cover. It was loose so I took pliers to the female part
of the plug and the trip up to Whistler Sunday night, the Jake work flawlessly. I added the retarder once on the trip.
This is my second trip to Whistler with the Jake. Last week going home it quit and then going down the longest hill, I was just goin to
apply the retarder and it came on. It worked all the way down the hill and I switched it between 3 and 6 cylinders and then it quit for
the rest of the trip. Over the weekend I checked the plug that is up by the valve cover. It was loose so I took pliers to the female part
of the plug and the trip up to Whistler Sunday night, the Jake work flawlessly. I added the retarder once on the trip. I left the
Jake switch in the on position so the Jake comes on when the throttle is released. In that position in cruise the Jake will come on
as soon as I go over the set speed. All I have to do it manually shift down if I need more braking.
It is sure nice having both the Jake and the Retarder. There is some hills at Whistler that I go down in 2nd gear just off idle and
the retarder is perfect for that. In the snow there is more control with the retarder and it comes on quicker. On long hills if the
Jake isn't holding I can add one notch on the retarder and hold my speed or I can use the retarder to slow the rig down so the
trans will shift into a lower gear and then the Jake will hold. Some of the grades are 9%.
Old guy, read here and elsewhere you shouldn't use retarder, cruise, Jake etc on slick surfaces. Whats your secret?
Yes I have read that and I agree if either one comes on with the throttle. When bringing the coach home after buying it I forgot
to take the retarder off and I took my foot off the throttle and the coach slid and I quickly put my foot back on the throttle and
everything was fine. I think I prefer the retarder for the snow as it is more predictable. I will use the Jake in the snow also on the
long hills. I put a foot peddle in and I have to shift down manually so again I'm in control. The M11 is usually running from
1200 RPM to 1500 RPM so the Jake doesn't come on vary hard. In driving in snow the retarder joy stick has to be in the off
position. I feel I have more control this way and my snow tires are on the rear. When driving rear drive cars I always shifted
down.
The Jake is the most effective at higher RPM and on our 2-cycle, it never is strong enough to cause the rear tires to lockup on wet roads. If there were to be a question, I would switch to 3 cylinders instead of 6. Plus, the Jake is only secondary to the service brakes. Waiting to get underway until morning black ice has melted is always a good idea.
I never turn it off, it's on all the time.
We never drive in snow with the coach as even one trip on wet treated roads can cause a lot of future corrosion with the design of our undercarriage. No matter how well you wash it afterwards, some residue will always remain.
Pierce
Well Pierce being a skier not much choice as the best skiing includes snow on the road. I put in a foot peddle so I can put it on
manually or have it work when the throttle comes off. I also want to put in a second peddle that will shift it down automatically
when the second foot peddle is installed. First I have to find the ECU for the transmission, any one know where it would be
on a 99 U320
That is getting close to when they moved it to the basement but first look behind the carpeted kick panel just beside where your left foot sets when you are in the drivers seat. If it isn't there then it most likely is hid in the basement somewhat behind and above the HWH compressor on the basement wall.
Mike
Thanks Mike I will check tomorrow.
I have checked, the only boxes I find in the basement are the ABS and the box for the leveling system. Nothing behind the kick
panel. I have tried to trace the wires from the shifter, no luck. I don't even know what EUC looks like.
If it was behind that kick panel just below the shift pad it looks like a little silver box about 3" wide and 5' long by 2" thick.
I bet it is hid behind that kick panel as when they moved it to the basement it will be in plane sight right where you were looking.
Somewhere here on the Forum is a pic. of both locations. I will see if I can find them and post a link.
Mike
Here is a link to a thread for what one looks like for about your year model
Chassis construction photos from Don and welding on your FT (https://www.foreforums.com/index.php?topic=14530.msg86176#msg86176)
I can't find the pic. of the one hid behind the kick panel
Mike the cable from the shifter goes under the dash on the left side heading towards the front and disappears into a maze of
wires.
Well your coach must have a new hiding spot for that Allison ECM, those two places is the only ones that I have dealt with. Redtractor may have some idea.
Mike
Thanks Mike, luckily there is no hurry to find it.
I finally found it and it is in the basement and it is tucked under a angled cover at the rear and beside a drawer. I will take a picture
of it tomorrow and post it. Does any one know if there are any spare wires from the dash to the basement area.
Here are the pictures of the ECU and with out a light I might have not found it.
When I did the fuel lines I ran 4 spare wires to the storage space. One was to be used for
giving the Allison computer a signal so when I'm using the Jake brake the trans will
call for 2nd gear and will shift down automatically as RPM is appropriate. In working
with the Allison dealer here I found that Foretravel had the wire from the computer to under the dash.
Having a tone tracer sure makes it easy to find the wire under the dash. We have a great Allison dealer
here. They are so helpful and it the computer needs to be programed to second gear
they will do that with out charge. The computer may be programed for 4th gear, I will find out soon.
The Allison computer can be programmed for ANY gear you want as your pre-select gear for retarder (or in other coaches an engine brake).
No right/wrong answers. More driver control, but requiring more driver input= 5th gear pre-select. Great for coming to a stop, but likely to "over-brake" on the road= 2nd gear pre-select.
Choose what fits YOUR needs.
I want mine set to 2nd gear as I am setting it up so I have a choice whether I use it
or not. If I just want to maintain the speed going down hill I will manually shift down
and if I want to stop or really slow down I will call for second gear. The wire I am using
is dead ended under the dash, not hooked up to anything. When I'm using the retarder it has
never felt to me that there is force down shift. I have never seen the engine rev up.
That MAY be the correct choice, but consider a 4th or 5th gear preselect. Then use the down arrow to select lower gears. That is a better choice on mountain grades, but agreed, 2nd is better if you are coming to a stop and don't want to fool with the down arrow.
The Jake on my 95 was a single speed with a 4th gear pre-select. I changed it to a two speed with a 5th gear pre-select and found that to be a more pleasurable driving experience.
jor
I had mine programmed for 5th as well.
I have put in a second floor switch for shifting down and I will use it when I want
to slow down or stop. When going down hills I have lots of time to manually shift
down as I have been doing which works great for me. It's when I need to slow down
quickly that I find it awkward trying to get at the shifter control and push it a whole
pile of times.
Arrived at June Lake, CA a couple of days ago after battling 60 mph gusts and then snow last night. Driving through the Sierras, the Jake is perfect. Never too much, never too little. It has been switched on ever since we bought the U300. It might be a slightly stronger on a 4 cycle but then you have the 3 cylinder position. It shuts off just before you get to a stop so is just one of those rare things that works as good or better than advertised.
The sound is so good driving through towns with the Detroit, I expect to get a recording contract soon. ;)
Pierce
Jor sent me a message as to how I put in the floor switch so I think I should add
it to this link. From the picture the foot switch on the right puts on the Jake and
the one on the left is to preselect a gear in the trans which for me is 2nd gear.
What I have done could be done with one switch but a relay would be needed as
the Jake is grounded to work and the preselect is powered. So I powered the switch
though the ignition with a fuse down to the left switch and from the switch to one
of the yellow wires in big cluster of wires. The yellow wire goes to #11 on the black
plug in the computer. I will go out on Sunday and try it out. There is no right way to
set this up, this is how I want it to work for me.
Went for a drive this morning, the Jake is working the way I want. It is
set for 2nd gear. Scott wanted to know how loud it is with a resonator and
it is loud. I can really here it, before I couldn't here it. Now I have to go and
remove a hydraulic line as one blew and will get a new one made up first thing
in the morning. The coach is about 15 minutes from.
Driving to the Ferry I got to use the Jake for a lot to stop lights, pushing the second
switch it calls for second gear and slows the coach quickly. Going down the back side
of the bridge shifting the trans to 4th held the coach perfectly and at the bottom I
was catching up to traffic pushed the second switch and slowed right up. Only using
the bakes to stop.
Coming home from Saskatuwan I took the #3 highway and got to really try out the
Jake Brake. On one hill I was able to pass 2 semis on a 6 to 8 percent grades. Most
of the steep grades on that route have sharp corners on the hills and usually at the
bottom so I would use the retarder to bring me down to speed. There is three big
passes on that route. Before we got to the #3 highway we were on another grade
that was 6 and 8 percent and at the end was a 11 percent grade with a 20 mile an
hour corner at the bottom. That was fun. On one descent the torque was getting
hot and I used Scotts idea that I could turn the fan to high speed with a switch.