| Author |
Message |
Geobus (4108gmc)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, December 01, 2004 - 3:04 pm: | |
I am having jake breaks installed in my 4108GMC.
There is a question if the brakes should be installed per the manufacture, using a buffer switch with a fast idle control on it and a lockout switch for the V730 automatic.
Someone else says no you don't need that. First, the lockout only works for a short time so forget it. Second, it is just as good to have a spring release toggle switch that supplies 24v from the dash back to the jakes. Thus, when you want the jakes on you hold the switch and to turn them off, just let go of the switch. They also say the low setting on the jakes are a joke so you don't need to even hook them up.
The coach is in the shop and I need some good answers. Looking forward to them.
Have a great day. |
Henry R. Bergman, Jr. (Henryofcj)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, December 01, 2004 - 4:20 pm: | |
Think you need to tell the tranny to remain in lockup mode as long as possible when decending hills and stuff. Otherwise the Jake will just stall the mill instantly.
Yeah, with your application, just wire the Jake to either max or nothing. I understand there are experts on this board who can lead you thru getting your automatic to stay in lockup mode...
...all the way into and including first gear. I for one do not know how to do this. Others may. With lockup in low gear, you Jake will work down to about 15 mph before the tranny goes to convertor mode. Good luck. |
Geobus (4108gmc)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, December 01, 2004 - 5:11 pm: | |
Thanks for the info. I hope someone will follow up with how to lock up the V730 clear down to 1st gear. |
Gary Carter
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, December 01, 2004 - 11:05 pm: | |
I'm probably wrong, but I thought the V730 didn't unlock until it was in 1st gear under about 15mph.
On our 4106 I had the jakes set up for both half and full. Used half a lot. Case in point from Flagstaff to Phoinex on I17, I could stay in 4th gear and toggle between half and full jake and maintain 60mph all the way down the hill and never touch the brakes. |
Buswarrior (Buswarrior)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, December 01, 2004 - 11:16 pm: | |
Hello Geobus.
I'm with Gary, having half and full jakes to work with is a good thing.
It greatly increases the flexibility of the speeds you can cruise downhill at without turning things on and off.
Full jakes are sometimes too strong for the speed and slope you are trying to maintain.
Under acceleration, the stock V730's in GM 5307's that I know lock up part way through 2nd gear under acceleration, fooling some into thinking that there are four forward gears.
Come on experts, share the jake/lock-up fix with this good busnut!
happy coaching!
buswarrior |
Richard Bowyer (Drivingmisslazy)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, December 02, 2004 - 9:21 am: | |
My experience and advice. Keep the dual range Jakes. I guarantee you will use it a lot.
Also, install the buffer switch. You do not want to be giving the engine fuel while trying to slow dow. The unburned fuel will be blown out the exhaust.
Richard |
Geobus (4108gmc)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, December 02, 2004 - 10:35 am: | |
I am very happy with everyone's feedback. As always the information helps me and others stay on track. The DD dealer who is working on it says the same thing, "you need the high/low." They also are working on a modification for the hard to find and expensive buffer/fast idle switch. I think they just about got it. Hopefully the modification will work just as well as the buffer/fast idle switch that is shown in Jacob systems spec. sheet. I should find out today.
Please keep the comments coming so I can make sure things were done correctly. As always the guy doing the work is convinced that his way is the right way. In my opinion, it usually is a good way but only one of many.
Have a great day. |
Bill Gerrie
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, December 02, 2004 - 11:06 am: | |
Geobus
I have had Jakes on my GMC for 15 years and would recommend the two settings as you don't always need full Jake on a slight grade. The V730 stays in lockup till it goes into convertor mode as it nears stopping speed. I never used a buffer switch and only had a micro switch on the accelerator arm on the top of the governor. It works perfect as it will only allow the Jake to work when the accelerator is fully off and the switch in the tranny is in lockup as they are wired in series with the power to the Jake. I hope you don't expect the Jake to work as it does on the trucks you see on the highway today. On a two stroke diesel it works but not near as well as on a four stroke. It works well enough that I only adjust the brakes about every 5 years. I leave the Jake turned on "HI" all the time and get to know when to take my foot off the accelerator all the way. You keep the accelerator on very slightly to avoid the Jake comeing on so you can coast without turning it off. You just get use to doing it and there is no fuel going to the engine with only a slight pressure on the accelerator pedal. Hope you can use this info. Bill |
Jim-Bob (Pd41044039)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, December 02, 2004 - 11:25 am: | |
I would also suggest that you have the DD guys set the Jakes up on relays (two, one for each half) so you are not running the full amperage through the switches. A number of people have reported having switches fail prematurely 'till they did that. The little 30 amp Bosch "cube relays" work great & are available everywhere if you ever need to replace one.
Jim-Bob |
Richard Bowyer (Drivingmisslazy)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, December 02, 2004 - 1:25 pm: | |
Jim-Bob, Good idea. I forgot that I had done this same modification after losing a couple of buffer switches. I installed the cube relays in the engine compartment so that only the relay control current was flowing thru the buffer switch to the control switch in the drivers compartment and then back to the relay cube.
Bill Gerrie, I have always been under the impression that a Jake worked much better on a two stroke than on a four stroke engine. However, I have never driven a four stroke with a Jake. Anyone else have an opinion?
Richard |
John Bessette (John_bessette)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, December 02, 2004 - 6:50 pm: | |
Jake on the four stroke works a lot better then on the two stroke.
John 4106 |
Buswarrior (Buswarrior)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, December 02, 2004 - 9:49 pm: | |
Hello Richard,
Experience driving them tells me four stroke Jakes are stronger than two strokes.
Who knows the technical reason why?
happy coaching!
buswarrior |
Craig Craddock (Gs4)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, December 02, 2004 - 10:30 pm: | |
The transmission lock out switch wired in series between the buffer sw and dash sw. I did not see where anyone has addressed this. The Jake manual says to intall it. I used one for 7 years and mine died reciently and I have bypassed it. I can not tell any difference. A friend of mine did not intall one in his V730 and has not had any problems without it for many years. I do not know why they say install it or what problems might arise without it. Maybe the Jake tech. people can answer your question. |
Bill Gerrie
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, December 03, 2004 - 12:49 am: | |
Craig
The buffer switch just stops you from fueling the engine when the Jake is working. It is the same as the switch I put on the accelerator control arm on the governor. You can get away without anything other then the lockup switch so long as you don't touch the accelarator when the Jake is on. It just makes more sense to be able to cut off the Jake with the action of the accelerator pedal then to have to turn off the dash switch. The cube relays are a good idea as the switches for the Jake are not cheap. Buswarrior. I can't answer why the difference between a 2 and 4 stroke other then the 4 stroke works better. Bill |
FAST FRED
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, December 03, 2004 - 5:32 am: | |
When installing the Jakes , I'm told the "proper" method is to torque the heads , have all the valves set and the injectors se and then the rack run.
Then the necessary bolts are removed , Jakes installed , and set up.
This takes time (esp when a tune up is needed , and the procedure reversed) about 2 days or so.
Save the old head bolts for the next tune up.
Lots of work , but when done right the engine PURRS ,
rather than just runs.
FAST FRED |
Geobus (4108gmc)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, December 05, 2004 - 11:13 am: | |
Well guys the job is done. I want to thank everyone for their feedback.
I will be testing it out over the next few weeks. Not only on this project but over the years, the DD guys have proven they are good. I could gone on about this for awhile, since recently I had a bad experience with work done at a nationally known coach repair facility.
I had rebuilt jakes installed and a microswitch at the throttle for buffering the jakes. The OEM buffer/fast idle switch could not be found (back ordered and expensive about $500). The unit was tunedup as FastFred recommended and it runs great. In the future, I will likely convert over to the relay setup. Everything seems to work like it was designed. After I get a few miles under my belt I will post an update.
Thanks again and have a great day. |
Geobus (4108gmc)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, December 23, 2004 - 7:23 pm: | |
Just a follow up.
I made it back for the holidays. The coach ran great. It was a real pleasure having the jake breaks. Ya, I could have made the trip without them but it was great having them. They are sort of like having 4wd on your truck (or car) or having a really fast internet connection instead of slow dial up.
It was great going through the mountains in GA, SC, NC, and KY and not having to break. The coach responded very well. I think one of the nicest things about having the breaks is the rapid deceleration in city driving. I don't remember any one discussing this benefit. Ya, one should drive so they don't need the jakes. But when you are trying to get 15 tons through stop and hurry up and go traffic, the breaks are nice. My wife liked them too, because the coach slows down faster, which she is use to in a smaller vehicle. Yes, after all is said and done it is nice having both high and low jakes, instead of just high as talked about above.
Have a great holiday. |