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  #1  
Old 11-06-2002, 12:18 AM
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heydave heydave is offline
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Question

The brakes on my 79 J-ten feel like manual brakes most of the time. I remember someone saying that the later G-Wags had a dual diaphram booster. Would this reduce the pressure it takes to apply the brakes?
Also, what years did they switch? Will this be a bolt on in place of my current one?
Thanks [img]smile.gif[/img]
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79 J-10 "The Gorilla"
  #2  
Old 11-06-2002, 12:40 AM
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stepsidedan stepsidedan is offline
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hello hello; anyone out there able to help me with better brakes on my fsj's??? because of large tires, the truck is really bad at stopping. i once read about a guy who put a brake master cyl. of a 93" dodge ram, and it was terrific. Anybody knows more about this????
regs,d
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  #3  
Old 11-06-2002, 02:46 AM
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turtlejoe turtlejoe is offline
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Dave,

I have a '78 Chief and swapped in the booster from a '79 J-20. My original was single diaphragm, the new one is a dual. I believe that '84 was the year that the GW's went to dual's, but don't know if it's a completely backward compatible swap with the master cylinder.

What an improvement! Keep in mind my booster was going bad anyway, so it's not a fair comparison. All I know is that the first time I really hit the brakes stuff came out from under my seats that I hadn't seen in quite a while. I always wondered what happened to that 1/4" ratchet!
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  #4  
Old 11-06-2002, 07:21 AM
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james1414d james1414d is offline
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mine now has a booster from a 70s' international dump truck. its a dual diaphram design and also uses a treadle for even more assist. it bolted right up to the stock location using the same bolt pattern, i did have to modify the cast iron bracket a bit to clear the new linkage. after the install i had about a half inch of travel before the brakes locked up! i was able to back off the rear brakes to add some extra pedal travel, and now i couldnt be happier. the booster sits up very high and away from the motor now too.
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  #5  
Old 11-06-2002, 08:36 AM
Sitting Bull Sitting Bull is offline
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I beleive you cannot use a dual diaphram from a later model Waggy because the master cylinders are different. You can, however, get a new dual diaphram booster for 78 J-20. That will be a direct swap. JUST BE SURE YOU TAKE THE MOUNTING BRACKET OFF OF THE BACK OF THE OLD BOOSTER BEFORE YOU TURN IT IN FOR A CORE CHARGE. Many people have missed this step, and had to go to a junkyard to pick up another adapter bracket. I did this swap on mine, and ran into no problems with the booster/master cylinder.
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  #6  
Old 11-06-2002, 01:38 PM
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BeerWolf BeerWolf is offline
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There's another brake help for those of you with a Dana 44 front axle with the disk brakes.

Powerstop/TRW makes a drilled, vented rotor that improves the stopping power, especially in the wet. They don't list the Jeep however. You have to get them for a '78 Ford Bronco.

Mine were $75 each, about $20 more than the stock replacements.

Got a moderate improvement in dry conditions, huge improvent on wet roads.
Haven't tried stream crossings yet, as there aren't any rivers with water in them around here!
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  #7  
Old 11-06-2002, 06:08 PM
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Check out Hydroboost Cadillac Eldorado 79-77 on the Net (google or so), there's a guy that replaces his vacuum booster by a cadillac version which is powered by the power steering pump. i'm curently looking for one of those to try it out, but apparently, it has alsready worked on several fsj's... c u daniel
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  #8  
Old 11-06-2002, 07:50 PM
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Frank in Norway Frank in Norway is offline
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I used the hydroboost from a 1991 Suburban when I converted my Wagoneer to hydroboost.
I had to drill two new mounting holes and cut the rod that goes to the brake pedal and welded on the one from original booster. Also the '91 has o-ring hoses so I had to get some new ones made that had the new fitting in one end and the old one on the other.
For the return I just spliced both return hoses with a T-fitting before going to the power pump.

There is a picture somewhere here http://home.online.no/~falmaas/axles.htm
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  #9  
Old 11-07-2002, 05:23 AM
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blt2krl blt2krl is offline
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RiverBeast has fantastic write up on the HYdoroboost.
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  #10  
Old 11-08-2002, 12:55 PM
davez26 davez26 is offline
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Not to be a butt-head, but the booster swap is a no-brain way to get decent brakes. I believe the cut off is '84 and up. You can use a dual-diaphragm booster to replace your single diaphragm. As for the master cylinder problem, leave your old one attatched to the brake lines and bolt it to the new booster. The dual diaphragm booster has metric threads, so keep your hardware sorted. I found it easier to remove the booster from interior side of the firewall. Other than that, you bolt it on and go, or stop or whatever. There are many threads that can be accessed via the search function, and I can't remember one where someone came across with the message that the swap made their brakes worse. I was fighting crappy-brakes-due-to-big-tires-syndrome for a long time, and this did the trick.
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Dave N. --- 1979 Cherokee S NT. 360-Quadrajet/TH400/Quadratrac/D44x2 4.10\'s, ARB front,locrite rear, 35x12.50 BFG Mud-Terrains. Onboard Air,4\"Superlift,2\"body. Warn Winch. Slight body damage. <br />\"Born to Wheel\', Forced to Work.\"
  #11  
Old 11-08-2002, 03:13 PM
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heydave heydave is offline
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So what you are saying is that the old master cylinder will bolt to a newer booster?
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79 J-10 "The Gorilla"
  #12  
Old 11-09-2002, 04:30 AM
davez26 davez26 is offline
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I just call 'em like I see 'em. I'm serious, this swap was so simple, and did so much, I wish I had known of it sooner. The cylinder bolts directly to the new booster. The hardest part of the whole deal is getting the old booster off of the donor with out stripping the nuts. I finally just pulled the brake pedal off, (it's held with one pin retained by a nut), and had the access. I'm not kidding, unless I am especially blessed, this was easy, had no side effects and works great!
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Dave N. --- 1979 Cherokee S NT. 360-Quadrajet/TH400/Quadratrac/D44x2 4.10\'s, ARB front,locrite rear, 35x12.50 BFG Mud-Terrains. Onboard Air,4\"Superlift,2\"body. Warn Winch. Slight body damage. <br />\"Born to Wheel\', Forced to Work.\"
  #13  
Old 11-11-2002, 03:23 AM
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Quote:
Originally posted by BeerWolf:
There's another brake help for those of you with a Dana 44 front axle with the disk brakes.

Powerstop/TRW makes a drilled, vented rotor that improves the stopping power, especially in the wet. They don't list the Jeep however. You have to get them for a '78 Ford Bronco.

Mine were $75 each, about $20 more than the stock replacements.
am i missing something? isnt a 78 ford bronco a 5 lug hub?are you using them on your 6lug hub,or have you converted your rig to 5 lug?

also,is that price for just the rotors? round here a stock rotor is only $25.not to imply that a drilled rotor isnt worth an extra $50 over stock for a street driven rig. i prolly woundt put em on my trail rig cause the little holes would fill up with mud
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  #14  
Old 11-13-2002, 04:08 AM
bvibert bvibert is offline
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Quote:
Originally posted by scotty:
...i prolly woundt put em on my trail rig cause the little holes would fill up with mud
Those little holes can cause stress cracks to form in the rotor too...
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78 Cherokee S, 360, TH400/QT, 61K orig miles
  #15  
Old 06-15-2003, 09:00 AM
Brad 79' Honcho Brad 79' Honcho is offline
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I have always *****ed about the brakes in my Honcho. I have started a restoration process and the first thing I tackled is the brakes. I can tell you all that in a 1979 Jeep J-10 you can buy a brake booster for a 1979 J-20 for it and it will bolt right up. No screwin' around, just drop the old and bolt in the new. The beauty of this upgrade is the relatively low cost of the parts compared to the, what I consider, DOUBLE the braking power. I can lock em up now! So do not be afraid, do it in the interest of safety! I am not sure but I believe that much of what hangs on the firewall from 79 thru 86 is very simialar, even for the other FSJ's. You do the research, I did on the 79' . Works REAL GOOD fer me. Here are some part numbers, good luck young Skywalker...

Brake Booster Info;
A1 CARDONE #54-71014 [Power Brake Booster] w/o Master Cylinder; Reman.; w/Dual Diaphragm
(WITH MASTER CYLINDER #50-1014) (I am not sure of brake line
connection compatibility with the loaded booster)

Brake Master Cylinder info; ( I used the
Wagner #F101254 )
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  #16  
Old 06-15-2003, 09:55 AM
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Crazy_Jeepman Crazy_Jeepman is offline
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I just pulled a Dual Diaphram Booster complete with the Master Cylinder..........Put the whole thing in my 79 Chero. Not hard, 45 mins later I was able to STOP the Tires!!!

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