Bolt in dual diaphragm booster upgrade

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bigwalton
Posts: 161
Joined: Fri Dec 21, 2012 10:33 am
Location: MI

Bolt in dual diaphragm booster upgrade

Post by bigwalton »

I searched on here and didn't see where this info had been listed. Folks mentioned the dual diaphragm upgrade, but not the specifics on years/models.

I need to replace the booster/MC combo in my 77 Cherokee before it gets running because it is obviously is leaking between the two and appears original. I try hard not to mess around when it comes to brakes or steering, so a new setup was in order.

Found this info online when trying to find a dual diaphragm booster upgrade (stock is a single diaphragm booster) because when I did a dual upgrade on my Scrambler it made a TON of difference.

Post up if there's other years/models that should be included. I would have thought that it would have worked in more years, but this is what I found:

A dual diaphragm brake booster from a '77-'79 or '86 to '89 J-20 will bolt in for '77-79 Wags and Cherokees.

Interestingly, when I went to the local part store to order it, it was cheaper to get the booster and MC separately than to get the entire assembly (they had both options). Also, by getting them separately, I get a brand new, not remanned, MC to boot.

Anyway, that's my effort to bring more of the good content from the soon-to-be-dead site
'77 Cherokee S - EFI 401
'84 Alaskan Postal Scrambler
'18 JKU Rubi Recon
'01 XJ - kid's DD
'01 XJ - winter beater
'18 Renegade
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Kenne
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Joined: Tue Jun 12, 2012 7:03 pm
Location: Sacramento, CA.

Re: Bolt in dual diaphragm booster upgrade

Post by Kenne »

do you NEED a dual booster?

the only reason i went this route is cuz of the 4 wheel discs.
"Kelly, a tiger has only one weak point, and that's it's ass. You gotta hit it point blank and you gotta hit it from behind!"

RamJetFSJ
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Joined: Fri Mar 22, 2013 12:36 pm
Location: Carpinteria, CA

Re: Bolt in dual diaphragm booster upgrade

Post by RamJetFSJ »

I did the J20 booster upgrade on my 80 Wag too. Sorry, I cant comment on how much it helped, as I never drove it w/ the standard booster. It is an easy upgrade though, and should allow you to put more pressure on the pads with less effort at the pedal.
80 Wag in 73 attire, Ram Jet 350 power

FSJ Guy
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Re: Bolt in dual diaphragm booster upgrade

Post by FSJ Guy »

IMHO, the dual booster is a NICE upgrade from the single diaphragm booster.
Ethan Brady

http://www.bigscaryjeep.com

Jeepless, but I still have a lots of old parts in my garage!
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bigwalton
Posts: 161
Joined: Fri Dec 21, 2012 10:33 am
Location: MI

Re: Bolt in dual diaphragm booster upgrade

Post by bigwalton »

I have two things to go on that made me do the dual booster considering that I plan to occasionally tow with it because this Cherokee has the OEM/optional tow hitch, is wired for trailering, and has a fresh rebuild with an RV cam:

1. We had a Grand Waggy a few years back that stopped ok, but not great, and it was a basically brand new brake system.

2. I put a dual diaphragm booster upgrade in my Scrambler and it made a great improvement.

I figure I'd rather it be almost twitchy on the brakes than borderline and this will serve as a family hauler most of the time, so better safe than sorry.
'77 Cherokee S - EFI 401
'84 Alaskan Postal Scrambler
'18 JKU Rubi Recon
'01 XJ - kid's DD
'01 XJ - winter beater
'18 Renegade
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Cecil14
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Re: Bolt in dual diaphragm booster upgrade

Post by Cecil14 »

Anything you can do to increase line pressure in the brakes is a good thing and will be noticed. How much? That's a matter of perspective.


aa
1983 J-10 - 4.6L(MPFI)/CS130D/Hydroboost/NV3550/D300/44/44/3.54/Disc-Disc/32s/42 gallon 'burb tank
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bigwalton
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Joined: Fri Dec 21, 2012 10:33 am
Location: MI

Re: Bolt in dual diaphragm booster upgrade

Post by bigwalton »

Can confirm that the dual diaphragm booster has no issues locking up the tires. Got my junk running this weekend.


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'77 Cherokee S - EFI 401
'84 Alaskan Postal Scrambler
'18 JKU Rubi Recon
'01 XJ - kid's DD
'01 XJ - winter beater
'18 Renegade
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babywag
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Location: Land of Fruit Loops & Coconuts

Re: Bolt in dual diaphragm booster upgrade

Post by babywag »

'83-up FSJ all used the same dual diaphragm booster.
-Tony
'88 GW (aka Babywag)

Eric1080
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Joined: Sun Feb 17, 2013 2:40 pm

Re: Bolt in dual diaphragm booster upgrade

Post by Eric1080 »

so any booster/mc ffrom any fsj 83 and up will be dual diaphram and will bolt into older jeep?
78J10 AMC 401 .30 over. 9.5-1. HOWELL EFI. Th400. leaky Dana 20. Dana 44HD EZ locker. Dana 60 welded disc brakes. Cooper Discoverer STT 315-75-16

FSJ Guy
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Re: Bolt in dual diaphragm booster upgrade

Post by FSJ Guy »

I think my 83 was a single. <shrug> It's been a long time since I've had that truck, however.... 83 could have been a crossover year, too.
Ethan Brady

http://www.bigscaryjeep.com

Jeepless, but I still have a lots of old parts in my garage!
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Cecil14
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Re: Bolt in dual diaphragm booster upgrade

Post by Cecil14 »

Betting all the grand wags (84+) got duals. I'm pretty sure my J-10 was a single diaphragm.


aa
1983 J-10 - 4.6L(MPFI)/CS130D/Hydroboost/NV3550/D300/44/44/3.54/Disc-Disc/32s/42 gallon 'burb tank
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