Adding a Jake brake

Topic: Adding a Jake brake (Read 4430 times) previous topic - next topic

Re: Adding a Jake brake

Reply #50 – August 22, 2020, 04:07:00 pm

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.

Re: Adding a Jake brake

Reply #51 – August 22, 2020, 05:03:03 pm

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.

Re: Adding a Jake brake

Reply #52 – September 04, 2020, 04:18:21 pm

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.

Re: Adding a Jake brake

Reply #53 – September 04, 2020, 06:28:56 pm

Quote from: oldguy – September 04, 2020, 04:18:21 pm

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

Pierce

Re: Adding a Jake brake

Reply #54 – December 15, 2020, 09:33:47 pm

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.

Re: Adding a Jake brake

Reply #55 – December 15, 2020, 10:01:12 pm

Does a Jake brake perform best at high engine RPM?

Re: Adding a Jake brake

Reply #56 – December 15, 2020, 10:26:38 pm

The higher the RPM the better it works the same as an exhaust brake.

Re: Adding a Jake brake

Reply #57 – December 15, 2020, 10:30:51 pm

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.

Re: Adding a Jake brake

Reply #58 – December 15, 2020, 10:49:31 pm

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

Re: Adding a Jake brake

Reply #59 – December 15, 2020, 11:17:20 pm

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.

Re: Adding a Jake brake

Reply #60 – December 15, 2020, 11:23:51 pm

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

Re: Adding a Jake brake

Reply #61 – December 15, 2020, 11:31:44 pm

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.

Re: Adding a Jake brake

Reply #62 – December 15, 2020, 11:40:57 pm

Quote from: oldguy – December 15, 2020, 10:30:51 pm

Does anyone know were the trans computer is located and how to wire it so it would get the signal to shift down.

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).

Re: Adding a Jake brake

Reply #63 – December 15, 2020, 11:44:06 pm

Quote from: Olde English – December 15, 2020, 11:31:44 pm

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.

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

Re: Adding a Jake brake

Reply #64 – December 21, 2020, 07:53:22 pm

Re: Adding a Jake brake

Reply #65 – December 21, 2020, 08:01:39 pm

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.

Re: Adding a Jake brake

Reply #66 – December 23, 2020, 12:59:09 pm

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%.

Re: Adding a Jake brake

Reply #67 – December 23, 2020, 02:35:32 pm

Quote from: oldguy – December 23, 2020, 12:59:09 pm

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?

Re: Adding a Jake brake

Reply #68 – December 23, 2020, 03:10:31 pm

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.

Re: Adding a Jake brake

Reply #69 – December 23, 2020, 04:29:46 pm

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

Re: Adding a Jake brake

Reply #70 – December 23, 2020, 04:44:34 pm

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

Re: Adding a Jake brake

Reply #71 – December 23, 2020, 06:54:13 pm

Quote from: oldguy – December 23, 2020, 04:44:34 pm

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

Re: Adding a Jake brake

Reply #72 – December 23, 2020, 08:07:27 pm

Thanks Mike I will check tomorrow.

Re: Adding a Jake brake

Reply #73 – December 24, 2020, 02:54:24 pm

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.

Re: Adding a Jake brake

Reply #74 – December 24, 2020, 03:37:35 pm

Quote from: oldguy – December 24, 2020, 02:54:24 pm

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

I can't find the pic. of the one hid behind the kick panel

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