Brake Booster upgrade ideas?

City
Killingworth
State
CT
#1
I have a 84 CJ7 with OEM Power brakes. I want to install a dual diaphragm booster (like in a 95 YJ) but the MC is configured with ports that face the passenger side instead of stock / driver side facing. Anyone have the part numbers to the YJ booster (or other dual diaphragm booster) and a M/C that fits the booster with Drivers side ports? OR.....Any other solutions beside hydro boost :). I have an auto tranny, 2150 carb and running 33's on stock axles (dana 30 and AMC 20) - Thanks!
 

John N

Addicted....Ex-SOA VP
LIFETIME
CJ-8.com Member
SOA Member
City
Rockville
State
VA
#3
I have a duel diaphragm booster with a larger m/c from Off Again Off Road, they call it their Navaho System. It works great, I have 33’s and an automatic FYI. It’s a complete bolt in deal, easy.
 
City
Killingworth
State
CT
#4
$ miles - Thanks - that was a great write up. I guess what I am looking for is a MC that is like the CJ with a YJ booster.

John N - thanks...will check off again off road and see what they have.
 

joshvt

Scrambler Enthusiast
LIFETIME
CJ-8.com Member
City
charlotte
State
nc
#5
i just had this one installed back in the fall. http://www.the-jeep-guy.com/brakes.htm (first one listed) I haven't put a lot of miles on it, but I have been happy with it. The rest of my brake system is stock and it will put your face in the dash if you mash the pedal with 33's. I found the "Jeep Guy" to be very helpful as well when ordering.
ENGINE-ABOVE.jpg
 
Last edited:
City
Killingworth
State
CT
#6
Thanks Joshvt - Looks like that fits without problems with the motorcraft carb - which is great news. will check out the jeep guy website.

Hey John N - are you sure the booster you have is a dual diaphragm. It looks like the navaho system is made by Tuff stuff and I dont see a dual diaphragm booster, but am going to call their tech support today to confirm. It might be that the 9 inch single diaphragm is stronger that the oem 8 and thats a good thing for stopping power?????
 

Kane

CJ-8 Member
CJ-8.com Member
City
Berlin
State
ct
#7
That is a dual diaphragm. I have the same one and got it from Morris 4x4 for about $235. It works good but the booster sometimes will make the brakes drag and I have to pull the vacuum hose to reset it. I have adjusted the rod lengths to factory specs and triple checked it all. Very odd issue.
 

John N

Addicted....Ex-SOA VP
LIFETIME
CJ-8.com Member
SOA Member
City
Rockville
State
VA
#9
JohnN - Any chance you have the part number of the unit you purchased from Off Again 4X4 - Sure would appreciate it!!!!
It’s definitely duel diaphragm. When I got it years ago, I called and ended up talking to Harold Off (RIP). He called me after I’d placed my order to go over just what I had so it’d be right when I got it. It was. I used my stock proportioning valve, not the one they sent. I don’t think there’s a part number for it, they aren’t that big of an operation. They want to talk to you about just what your setup is when you place an order.
http://www.offagain4x4.com/navajo_brakes.html
 
City
Killingworth
State
CT
#10
I finally got through and talked with Off road and they confirmed it was a dual diaphragm booster. Its $400 shipped which is quite a big jump from the $130 version I see guys install and have good luck with and another version which is made in the U.S.A., but is single diaphragm 9 inch booster instead of the OEM 8 inch for ~$200. I tried to take my booster and MC off last night but have a brake line starting to twist when I tried to unbolt it from the M/C. I am soaking it and hopefully I wont have to replace the line because it looks like its a pain to do and that it goes into the proportion valve on the frame rail.
 

Kane

CJ-8 Member
CJ-8.com Member
City
Berlin
State
ct
#11
The line will take a couple days of soaking to remove but those lines are very easy to swap out if needed so do be afraid of it. Inline Tube makes a nice kit for the Jeep and it all prebent. I used it for my Jeep.
 

jweakley

Basic User
City
clarksville
State
tn
#14
I am currently installing the 8" dual booster on my 84. The jeep did not have power brakes and I am going up to 37s. I have most of the work done. I am going to bend the new lines and bleed the system tommorow. Only problem is I am having a hard time finding a good source for the vacum line.

The jeep has the 4 cyl 258, no AC. I recently wired it back to a 83 to delete some of the extra emissions and the ECM. You will see several capped off vac lines on the picture. If I can get it to upload correctly.

All of the images and diagrams I have found in my Google searching do not show the manifold vac. I was told it's directly under the carb but maybe I'm blind but can't find it.

Any ideas? IMG_20180523_232719.jpg IMG_20180523_232733.jpg
IMG_20180523_232742.jpg IMG_20180523_232707.jpg
 

FLCJ8

Legacy Registered User
City
Palm Bay
State
FL
#15
Not sure of a port on the manifold for the 4 cyl., but couldn't you get manifold vacuum from this port?

carb.JPG
 

jweakley

Basic User
City
clarksville
State
tn
#16
I think you would. With my existing vacum line setup that port actually tees out and connects to the line that runs from the PCV valve to the canister. I'm in the process of deleting some of the sensors that were required for the old wiring harness.

Sorry I didn't realize I had that disconnected at the time of the picture. With that Port being connected to a vapor line rather than a traditional vacuum I was afraid to hook into it.
 

Kane

CJ-8 Member
CJ-8.com Member
City
Berlin
State
ct
#17
I tied my line in right below the carb mount on the manifold using a spectra fitting from Autozone. You can see the line right below the throttle body linkage. I don't see a spot for you there but I see a plug fitting on top of your manifold behind the carb that you could use if you install a barbed fitting there.
 

Attachments

zdatjeep

Basic User
City
merritt island
State
fl
#18
Hi everyone, I just want to pitch in here on the brake topic.
I just went ahead and ordered the Morris 4x4 disc/drum kit.
It appears some of the suppliers are using either the Morris or TuffStuff kits. Some of the part numbers are even comparable with just a change of prefixes.
So the much talked about Vanco supplier is no longer offering vacuum kits for the Jeep- listed last year at 400.00.
These are still active sources from what I can tell so I hope this helps someone:

http://www.offagain4x4.com/navajo_brakes.html
https://www.summitracing.com/search...ssemblies/year/1983/make/jeep/model/scrambler
https://www.morris4x4center.com/pow...-master-cylinder-disc-drum-mbm-pbuj7486d.html
http://www.the-jeep-guy.com/brakes.htm
I believe but have no proof that the first two and last two on the above list are essentially the same product.
FYI- Morris was offering a 10% off code online so I picked up my dual diaphram 8" for 225.00 w free shipping.
and now I got to deal with the nonfunctioning proportioning valve- what a stupid place for AMC to mount it- if I had the dough I would do a complete re do of the brake lines and add an adjustable valve up at the top or in the cab...
I will post an update on how it works out.
 

jsteed

CJ-8 Member
CJ-8.com Member
City
Seattle
State
WA
#19
Just curious, did you consider a hydraboost system? they can be had from the junkyard for pretty cheap. Its what I'm considering, but I havent done it. The stopping power is supposed to be excellent... when the engine is running.
 

jweakley

Basic User
City
clarksville
State
tn
#20
Sorry for the delay. I was able to use the vacuum port on top of the manifold that was locked up. Thank goodness for pb blaster. I sprayed the bolt every time I walked back to the Jeep for two days and it came loose easily.

The booster makes all the difference in the world. Pedal is now as soft as my truck's, but if I had tires any smaller the 35s they may be too grabby.
 
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