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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: Sharkbait on September 13, 2015, 03:13:04 PM

Title: 8V71 Jake's
Post by: Sharkbait on September 13, 2015, 03:13:04 PM
Okay, thought about posting to the old thread about Jake Brake's but I got a pretty stern warning that I probably should start another thread so, here it is.

I'm looking for a set of Jake's for my 8V71. I've seen a set on Fleabay for about $600 for an 8V92 but it's 24V so I think I'd need a set of 12V solonoids and I'd need a set of "Bridges?" which from what I've read are getting harder to find. I've read the old post's on the pro's and con's etc. The steepest hills I've pulled has been I-40 from Bakersfield to OKC. Both ways. I did it okay with my 4 speed spicer but I will admit there being a bit of a pucker factor going downhill sometimes. In my advancing age I could use a little more piece of mind, as long as it doesn't get too expensive.

So here's the question, anybody know where I can get a set? And or a parts list so I maybe can start accumulating the parts for a future installation? Thanks guys, Phil
Title: Re: 8V71 Jake's
Post by: eagle19952 on September 13, 2015, 03:17:10 PM
where are you located ?
Title: Re: 8V71 Jake's
Post by: Sharkbait on September 13, 2015, 03:21:06 PM
I'm in Jacksonville Fl. now but my bus is in Mariposa CA. I plan to go out there in a couple of weeks and start bringing it back here. Thanks, Phil
Title: Re: 8V71 Jake's
Post by: luvrbus on September 13, 2015, 03:47:55 PM
You need  
4 masters with solenoids  
4 drones  
16 long oil bolts    
4 jumper tubes with seals    
32 Jake fuel lines  
2 wiring harness ,regular automotive wire is not good under the valve covers  
Jake on/ off switch with a hi/lo switch if you want 2 stage brakes
wiring to the front from the rear that depends on what you want in the way of single stage or 2 stage  
2 pass through plugs for the head wiring
1 buffer switch either with hi idle or no hi idle  
71 bridges
A Jake gauge  
Valve covers and the pricey silicone gaskets  
A redo of your tail gate for the lower valve cover  
Tools to reset the rack,bridges and valves a fuel line socket is nice to have    
Try to avoid the housings with only 71 stamped on the housing go with housings marked 71/92A 
 Down Load the instructions from Jake
If you don't find a set I have several sets with bridges if you come down I 40 towards Needles Ca
Title: Re: 8V71 Jake's
Post by: OneLapper on September 13, 2015, 06:03:29 PM
Quote from: luvrbus on September 13, 2015, 03:47:55 PM
You need  
4 masters with solenoids  
4 drones  
16 long oil bolts    
4 jumper tubes with seals    
32 Jake fuel lines  
2 wiring harness ,regular automotive wire is not good under the valve covers  
Jake on/ off switch with a hi/lo switch if you want 2 stage brakes
wiring to the front from the rear that depends on what you want in the way of single stage or 2 stage  
2 pass through plugs for the head wiring
1 buffer switch either with hi idle or no hi idle  
71 bridges
A Jake gauge  
Valve covers and the pricey silicone gaskets  
A redo of your tail gate for the lower valve cover  
Tools to reset the rack,bridges and valves a fuel line socket is nice to have    
Try to avoid the housings with only 71 stamped on the housing go with housings marked 71/92A 
 Down Load the instructions from Jake
If you don't find a set I have several sets with bridges if you come down I 40 towards Needles Ca


Did you need to look up all the parts you listed??  Or do you just *know* what parts are needed?  I can't think of anything you missed!
Title: Re: 8V71 Jake's
Post by: muldoonman on September 13, 2015, 06:09:23 PM
Quote from: OneLapper on September 13, 2015, 06:03:29 PM
Did you need to look up all the parts you listed??  Or do you just *know* what parts are needed?  I can't think of anything you missed!

Now you are talking about Cliff. He's Probably forgot what most will ever know about these rigs. ;D
Title: Sticky? ...
Post by: HB of CJ on September 13, 2015, 06:39:32 PM
Excellent list and thank you.  Book Marked.
Title: Re: 8V71 Jake's
Post by: luvrbus on September 14, 2015, 05:19:33 AM
Not from a book Mark  ;D and the price of new Jake parts will blow your mind the part that gets me is $3.85 for the little oil jumper tube seal, but I have a stash of those now if you ever need some
Title: Re: 8V71 Jake's
Post by: Sharkbait on September 15, 2015, 01:41:28 PM
After reviewing the list of items Cliff provided (very thorough) thanks Cliff, I downloaded the install and parts manual off the Jacobs Brake site. Reading through the parts manual and install directions was enlightening! But I have a couple questions. I've never used my high idle, would I need a high idle switch? Also the instructions refer to a "clutch switch", I suppose it dis-engages the Jake's when I depress the clutch?  It looks like the dash switch is just a toggle switch, anything special about it?Jake guages appear to be feeler guages? I've got a line in on most of the major parts except those elusive valve covers. Is there a way from looking at a picture to tell if they'll work? How about using the spacers? Pro's, con's? Thanks guys, Phil
Title: Re: 8V71 Jake's
Post by: luvrbus on September 15, 2015, 02:12:31 PM
You don't need a clutch switch they are more trouble than it's worth,if do not use the fast idle go with the electronic buffer switch,spacers are the pits to stop from leaking,I prefer the Jake gauge over feeler gauges you just slide in under start adjusting when it stands up you are there no poking around with feeler gauges 
Title: Re: 8V71 Jake's
Post by: Sharkbait on October 06, 2015, 04:50:17 PM
Using Cliff's list, after a couple of weeks of successful foraging I've managed to come up with most of the parts I need. Even the ever elusive 71 exhaust bridges. But I do have a couple of questions: I've got the tall valve covers and 3 long bolts and one shorter bolt. Don't I need 4 long bolts? I still need fuel lines and a buffer switch. If I can figure out how to post a pic you'll see the parts I got. What do you think? Thanks guys, Phil 
Title: Re: 8V71 Jake's
Post by: luvrbus on October 06, 2015, 05:36:07 PM
You can use a extension for the short bolt,looks it was used on a engine with fuel modulator fwiw your engine may have extensions you need to remove to use the longer bolts.The valve cover kits with bolts, washer,gaskets and the bolt seals are cheap like 25 bucks a side.You don't need to change the stands and shafts unless you have the very old stands 
Title: Re: 8V71 Jake's
Post by: Sharkbait on October 06, 2015, 06:37:29 PM
Thanks Cliff, I was wondering what all those extra parts were for. When you say $25 bucks a side does that include the sporty valve  cover gaskets? I heard those were a bit expensive on their own.
Title: Re: 8V71 Jake's
Post by: luvrbus on October 06, 2015, 06:43:56 PM
Yep Diesel Pro sells it in a kit lol DD will make you have the big one just for the silicone gasket
Title: Re: 8V71 Jake's
Post by: TomC on October 07, 2015, 06:58:47 AM
I have Jakes on my 8V-71. Being an old truck driver, it was among the first things installed before I even brought the bus home. Properly adjusted (Don Fairchild did the adjusting-don't remember the specs) they work very well. With me pulling my car at 34,750lbs (way more than a 4106) going north on I-5 Grapevine the big 5 mile 6% I had to switch from one head to two heads to keep from slowing down too much. Also, if you ever explore in the hills, having the Jakes is a real brake saver. I kept my V730 down in 1st and got torque converter lockup above 20mph. With your 4spd the jake will just about put you through the windshield in 1st gear-so a on-off-on or off-on-on will be good with low just one head and high both heads. Good Luck, TomC
Title: Re: 8V71 Jake's
Post by: Sharkbait on October 07, 2015, 05:06:33 PM
Thanks Tom, I was originally going to go with just an on-off switch never having used jake's before but after reading your post I might want to consider an off low-hi configuration.

A question about the buffer switch. It's the last part I need to make this work. Can I use a buffer switch for an 8V92, or a 6V92? Are they all the same? There's a guy on fleabay selling fuel lines for $116.00  or there abouts. But I still need a buffer switch. Anybody out there in Busnut land have one they would be willing to part with? Thanks for all the help you guys, Phil