Author Topic: Cost and difficulty of adding a jake brake to a GM4106  (Read 16285 times)

Offline technomadia

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Re: Cost and difficulty of adding a jake brake to a GM4106
« Reply #15 on: October 11, 2012, 06:53:39 AM »
Wow 2000 for the jake brake, 2500 for new tires, and 6000 for the converted bus......... Is the jake something that is a must?

Bus reality check (sorry, I tend to do this).

I second this reality check as well.

If $2k is causing you concern, I caution you to seriously look at your budget for this project.  When we bought our 4106 last summer, within the first few months we had another $8k in expenses in bringing her up to date in maintenance, and are budgeting about $2-3k a year for continue maintenance and repairs.  Plus have funds put aside for big stuff.   And we're just now starting to add on optional mechanical features as we learn what is worthwhile modifying and what is not.

However, this is exactly what we planned for when we embarked on this adventure, with lots of thanks to the folks on this board for setting our reality to realistic.

You just simply can't expect "everything" to be right on a 50+ year old bus that was likely home converted 20 or more years ago. If your potential bus is anything like most of the ones others have taken on...  you'll have an unending list of maintenance & projects to tackle for a long time :)   

The good news is..   almost a year and half later, we have an absolutely amazing & distinctive home on wheels that is perfect for us, for considerably less money than we would have spent on a "quality" sticks-n-staples Class-A. And we couldn't be happier.

 - Cherie
Cherie and Chris / Bus tour: www.technomadia.com/zephyr
Full-time 'Technomads' since 2006 (technology enabled nomads)

Offline RnMAdventures

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Re: Cost and difficulty of adding a jake brake to a GM4106
« Reply #16 on: October 11, 2012, 08:08:02 AM »
If I were you, I would not worry about Jakes unless your bus is an automatic and then ONLY if the idea of not having them causes you high stress. As Gus mentioned, he has done a lot of mountain driving with an automatic and standard with no problems. With that said, research and practice driving it. The gentleman I purchased my 4106 from drove it all over the country with no jake brake and it is automatic. .

As to the reality check, I will add my 2 cents.

If you are buying your bus for $6000 and the motor, brakes, air system, tires, fuel system, overall body, wiring, and RV systems check out good... then you are getting a great deal. If you are getting a 4106 in decent shape for that price, you are miles ahead compared to where you would be if you purchased a traditional S&S RV. Once you fix something, typically it will last a very long time after that if it is properly maintained.  If you can turn a wrench, then you can save some bucks along the way. If your engine blows up it could cost you $16k to fix it if you have it rebuilt or you can install a used engine for MUCH much less.

I own and work on my own Harleys as well. If I had the stealership maintain and do all repairs then it would be much more expensive. I could pay them to install cam tensioners for $1100 or put them on myself for $200. For a mechanic to install head gaskets on a Powerstroke $3000... transmission exchange on a Coachmen $3500. Nothing is cheap... While it is a 50 year old bus, keep in mind it is a 50 year old bus that is still on the road. If it is maintained, it will be on the road in 50 years.
Mike & Rosemarie
1964 PD4106-2626
DD8v71 & Allison v730

Offline OneLapper

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Re: Cost and difficulty of adding a jake brake to a GM4106
« Reply #17 on: October 11, 2012, 07:00:02 PM »
Ok..... I recently installed Jakes on my 4106.  

I bought them used with a pair of tall valve covers from the parts dude at Fleetpride; $500
Jake rebuild kit for masters and drones; $280
Jake micro and contol switches; $180
Machine shop work to make custom plug for oil vapor separator for front valve cover; $50
New tall valve cover (for rear bank) with no holes for oil separators; $260
Labor to adjust jakes and re-run the rack; $300

I rebuilt and installed them myself

Total cost; $1,570.00.

In my opinion well woth it, but I agree with Clifford, at 65mph in fourth gear you don't feel it much.  Downshift to 3rd at 60 and wow!  Second gear, 9% grade and you'll need to toggle between Hi and Lo to keep the speed up!


I'm not a mechanic..... but I owned Deere dealership for many years, and prior to that I was doing on the road repairs, blah blah blah, race cars, etc etc etc..... I'm not afraid of anything mechanical.

My 4106 is a standard.  I installed Jakes because I tow a car trailer.... it's a third brake system that I can use in junction with the service brakes and trailer brakes.

Mark
OneLapper
1964 PD4106-2853
www.markdavia.com

Offline luvrbus

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Re: Cost and difficulty of adding a jake brake to a GM4106
« Reply #18 on: October 11, 2012, 07:04:27 PM »
The last Jakes I installed was a 4106 with a 4 speed
Life is short drink the good wine first

Offline RnMAdventures

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Re: Cost and difficulty of adding a jake brake to a GM4106
« Reply #19 on: October 11, 2012, 08:26:03 PM »



I'm not a mechanic..... but I owned Deere dealership for many years, and prior to that I was doing on the road repairs, blah blah blah, race cars, etc etc etc..... I'm not afraid of anything mechanical.

My 4106 is a standard.  I installed Jakes because I tow a car trailer.... it's a third brake system that I can use in junction with the service brakes and trailer brakes.

Mark

Towing a car trailer is a good reason to install jakes, but what data did you use to determine if the bulkhead/rear structure could handle the weight you are hauling?
Mike & Rosemarie
1964 PD4106-2626
DD8v71 & Allison v730

Offline RnMAdventures

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Re: Cost and difficulty of adding a jake brake to a GM4106
« Reply #20 on: October 11, 2012, 09:01:35 PM »
The last Jakes I installed was a 4106 with a 4 speed

Clifford is one of the folks that I highly respect on this forum. He knows his $#!% when it comes to buses.

If I just purchased a 4106 (like I did last year) and I was budget minded (like I am), I would thoroughly go through the other systems on the bus before I added Jakes. These old buses traversed this country for many years without Jakes.
Mike & Rosemarie
1964 PD4106-2626
DD8v71 & Allison v730

Offline luvrbus

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Re: Cost and difficulty of adding a jake brake to a GM4106
« Reply #21 on: October 12, 2012, 06:50:57 AM »
I have to agree with you Mike, Jakes are overrated on a 2 stroke I install the Jakes for people if it is one of the just got have things

 I have installed Jakes on 1 bank on 8v71's for people why I have no idea they don't do much good on 4 cylinders
Life is short drink the good wine first

Offline Utahclaimjumper

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Re: Cost and difficulty of adding a jake brake to a GM4106
« Reply #22 on: October 12, 2012, 10:07:25 AM »
 As has been said,,your situation will determine the need for Jakes. My 06 had an Allison VS2-8, this trans will kick out of gear (freewheel) at 18 miles per hour.. Many times 18 was faster than I wished to go, as in a 10% grade at 10,000 Ft. and a twisty road with tight turns,, I really smoked my service breaks on that one,,, and I had Jakes...>>>Dan  (Don't ask how Jakes work when not in gear)
Utclmjmpr  (rufcmpn)
 EX 4106 (presently SOB)
Cedar City, Ut.
 72 VW Baja towed

Offline lostagain

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Re: Cost and difficulty of adding a jake brake to a GM4106
« Reply #23 on: October 12, 2012, 12:30:34 PM »
You don't "need" Jakes. All they do is let you go down the hill one gear higher. Sure they are nice to have, but we drove buses all over the mountains of the West without Jakes until the 1980s when they started to come with the 102s.

And I don't understand why you would need them more with an automatic than with a manual. My 5C has a HT740 and it stays in whatever gear you put it in.

JC
JC
Blackie AB
1977 MC5C, 6V92/HT740 (sold)
2007 Country Coach Magna, Cummins ISX

Offline TomC

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Re: Cost and difficulty of adding a jake brake to a GM4106
« Reply #24 on: October 12, 2012, 10:28:21 PM »
If you have an HT740 you can get by without a Jake since you have one more lower gear then the V730.  The V730 is like an HT740 starting in second.  I really don't think I'd be here today (or at least my bus in one piece) if it weren't for the Jakes and with Don Fairchild adjusting them tightly to be very effective.  I sometimes get on small roads in the mountains and am driving in 1st gear the whole way.  After driving my truck 1.3 million miles, and now with my bus, I'd NEVER be without a Jake-just to much like Russian roulet-yes you might get by once or twice or even a dozen times-it only takes once with overheated, glazed up brakes to bring things to a crashing stop.  Good Luck, TomC
Tom & Donna Christman. 1985 Kenworth 40ft Super C with garage. '77 AMGeneral 10240B; 8V-71TATAIC V730.

Offline TomC

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Re: Cost and difficulty of adding a jake brake to a GM4106
« Reply #25 on: October 12, 2012, 10:31:19 PM »
One more point-Jake brakes are now built into the Detroit DD13, 15 and 16; Built into the Cummins ISX 15 and new ISX 12.  Volvo has their own version as does M.A.N. (Internationals MF engine) and Paccars MX engine by D.A.F.  Good Luck, TomC
Tom & Donna Christman. 1985 Kenworth 40ft Super C with garage. '77 AMGeneral 10240B; 8V-71TATAIC V730.

Offline luvrbus

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Re: Cost and difficulty of adding a jake brake to a GM4106
« Reply #26 on: October 13, 2012, 07:18:46 AM »
I am not opposed to Jakes on a 2 strokes but I have saw it to many times people coming down from Flag to Phoenix trust the Jakes to slow down and brake smoking like crazy and they going to fast to change gears or they miss a gear and the ride is on.

People need to be sure they are in the right gear using the Jakes when running 3:36 gear they are not going to do any good in 4th gear automatic or standard 

Like TomC with the transit gearing they work fine in about any gear folks need to know how and when to use the Jakes that is the point I am trying to get across to you guys change to lower gear at the top of the descend don't put your life on the line depending strictly on the Jakes not a good idea IMO 

I have tried all the different setting like Don my friend with even more valve spring I cannot tell the difference between the standard 0.59 and 0.55 myself

good luck 
Life is short drink the good wine first

Offline Barn Owl

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Re: Cost and difficulty of adding a jake brake to a GM4106
« Reply #27 on: October 13, 2012, 08:32:02 PM »
My 4106 came with Jakes. I like the fun factor of them, but truth is you can live without them. My 2 stroke mechanic thinks Jakes are worthless on them because you don't get much bang for the buck.

I still drive as if I didn't have them though.
L. Christley - W3EYE Amateur Extra
Blue Ridge Mountains, S.W. Virginia
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Have fun, be great, that way you have Great Fun!

Offline Barn Owl

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Re: Cost and difficulty of adding a jake brake to a GM4106
« Reply #28 on: October 13, 2012, 09:11:51 PM »
Quote
65mph in fourth gear you don't feel it much.  Downshift to 3rd at 60 and wow!  Second gear, 9% grade and you'll need to toggle between Hi and Lo to keep the speed up!

Jakes can only remove a fixed amount of energy at any given rpm, the maximum absorption occurring at the highest rpm. Keep in mind though that it is a fixed amount. The energy you are trying to get rid of is not.

This equation explains what I am talking about:

KE = 1/2 * m * v^2

where m = mass of object

and v = speed of object

This equation reveals that the kinetic energy of an object is directly proportional to the square of its speed. That means that for a twofold increase in speed, the kinetic energy will increase by a factor of four. You can see why at 60 mph Jakes don't feel like much compared to 30mph. Your Jake's ability is fixed, but you have 4x the energy to dissipate at 60, so the effectiveness of your Jake is a much smaller percent at high speeds. Even without Jakes this same equation explains why you gear down and lower your speed. Remember your brakes have a fixed ability also, unless of course you overheat them, and then you are left finding other unconventional sources of energy absorption like trees, banks, other vehicles, run-outs etc.
L. Christley - W3EYE Amateur Extra
Blue Ridge Mountains, S.W. Virginia
It’s the education gained, and the ability to apply, and share, what we learn.
Have fun, be great, that way you have Great Fun!

Offline harleyman_1000

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Re: Cost and difficulty of adding a jake brake to a GM4106
« Reply #29 on: October 20, 2012, 04:08:09 PM »
 First I want to say thank you to everyone for their knowledge.  I am now thinking I will pass on the Jake  brake for a while. Can you answer questions about the mph on the 4106 with manual? I was told about 7 mpg? Someone with a 4104 said he got around 10 to 12?  The 4106 I'm thinking about has a serial number of 41062732. Can someone give me some imfo on this buses history? The asking price is 5000, but I am trading my truck and 1000 for it so will be getting started for cheap other than 1600 for 4 retreads and 2 new tires, and the cost of new house batteries. What part of the country does everyone live in?
Scott 
St.Louis Missouri

1958 GM 4104 Extended 2 feet, with a 6v92 and 5 speed automatic

http://s783.photobucket.com/user/harleyman_1000/library/Gm4104%20bus?sort=3&page=1

 

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