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View Full Version : Kung Fu Brakes One Ton Brake upgrade



Alaska ZJ
06-28-2004, 10:18 AM
Alright I have to first give credit where credit is due. BigDude from the Pirate Bullitin BOard tried this first (at least to my knowledge) and directed me on what to look for and do.

His was a YJ and he just had to do the MC (Master Cylinder). Well our ZJ's have a double diaphram booster and the E350 MC will not work with it. So I snatched a single diaphram booster off of a 88 XJ. Booster bolted right up inplace of the the old booster.

The pedal is going to be very stiff. Personally I like it like this. I seem to have more control over my brakes. Now my wife who is on the small side absolutly hates the brakes in the Chuggy. She thinks it takes WAY to much pressure to get the brakes to catch hard. BUT they will catch hard. I have locked all 4, 36 inch TSL's at about 40 mph. I can stop going down Launchpad in Moab without so much as a worry.

Anyway here is the write-up page. Feel free to fire any questions.

http://www.akextreme4x4.com/tech/brake/master_cylinder.htm

and because threads without pictures suck. Here is the E350 master mated up to the 88xj Booster installed on my 93 ZJ.

http://www.akextreme4x4.com/images/tech/brakes/MCandBooster.jpg

Trancezj
06-30-2004, 03:01 PM
So you do away with this and put a new one in?
http://www.akextreme4x4.com/images/tech/brakes/zjmc.jpg

Trancezj
06-30-2004, 03:03 PM
I ask because I don't see anywhere on the other part to put fluid in

Alaska ZJ
06-30-2004, 04:04 PM
that is the Stock ZJ mastercylinder. You no longer need it or anything attached to it. I just wanted to show what it looked like and why the E350 would not bolt in it's place.

Nordic1
09-01-2004, 02:55 AM
Brent, did you bolt up the master cylinder to the stock lines (with the ABS crap) or did you route new lines?

Nordic1
09-01-2004, 03:00 AM
edit: never mind i read your writeup on the other page... you did bypass the ABS. Do the brakes ever lock up funny without the proportioning valve?

Alaska ZJ
09-01-2004, 11:28 AM
No, the brakes are very predictable. The rear actually engage the same time as the fronts without the proportioning valve.

This is fine for me. It is different than the stock form though. In the stock form the fronts will grap slightly prior to the rears engaging.

Also with the single diaphram booster it takes some leg power to get everything stopping. My wife doesn't like to drive the chuggy for this reason. I just push harder....but she thinks the brake pedal is too hard and that it takes to much input to get good braking out of the system.

A double diaphram XJ booster will work inplace of the single diaphram XJ booster I used. Direct bolt in swap.

deadman
05-16-2005, 04:07 AM
Has anyone tried the corvette MC?

I've searched on pirate and my brain hurts now... I got all kinds of MC out of the search. Dodge 3500, Pontiac Firebird, Corvette, E350, and a Mercury one.

From what I read the E350 MC is only for front discs and rear drums.
Since one reservoir is smaller than the other.

I got discs at all corners, two calipers for each disc. So I got a lot of fluid to move. Has anyone done the Kung Fu brakes with all disks, and what MC did you use?

thanks
Sascha

deadman
05-19-2005, 06:02 PM
nobody? :smt026

MaineZJ
05-19-2005, 08:14 PM
you got 8 calipers? what you turning - 62s or something?

deadman
05-20-2005, 03:44 AM
No, just 42s for now.
But my new axles come stock with 2 calipers...

http://jeep.cfasp.de/upload/9739.jpg

Nordic1
06-21-2005, 10:12 AM
I didn't catch it the first time but looking at this again...

http://jeep.cfasp.de/upload/9739.jpg

portals? bastid

deadman
06-21-2005, 06:51 PM
:smt045

Still don't know what to do about the brakes tho. I guess I'll just have to try the E350 Master, and see if it works. But try finding one in Germany! :shake:

ATL ZJ
06-21-2005, 08:47 PM
:smt045

Still don't know what to do about the brakes tho. I guess I'll just have to try the E350 Master, and see if it works. But try finding one in Germany! :shake:

I can pull one and mail it to you. How much is it worth to ya?

Kraqa
06-21-2005, 08:55 PM
I didn't catch it the first time but looking at this again...

http://jeep.cfasp.de/upload/9739.jpg

portals? bastid

hmm i think there volvo's not portals.

deadman
06-22-2005, 02:54 AM
I can pull one and mail it to you. How much is it worth to ya?

I don't know about a used one... but how about the next time someone gets something for themself at NAPA, they buy me the remanufactured one that Alaska bought?

http://www.akextreme4x4.com/images/tech/brakes/e350mc.jpg


In his write-up he says it costs $25... + $20 for your troubles + shipping.


@Kraqa: That is a 406 Unimog axle... not an actual pic of my one, but I got the same axle.

scubatch2
02-05-2006, 01:12 AM
if I have disc at all 4 corners will this work ok,or should I get the double diaphram booster?

nate
02-05-2006, 12:46 PM
Looks like a portal axle to me. Volvos use portal axles.


hmm i think there volvo's not portals.

JeepinJoe
02-06-2006, 04:36 PM
Ok so why not use a WJ booster and m/c setup instead? Doe's that E350 MC make that big of differance?

JPZJ
03-01-2006, 11:44 PM
Ok so why not use a WJ booster and m/c setup instead? Doe's that E350 MC make that big of differance?


I'd like to know also...can anyone tell me and Joe why not use the WJ stuff as opposed to the XJ /E350 setup

I've got disc/disc set up also ...Thanks

JPZJ
03-07-2006, 12:56 AM
Can anyone commnet on the WJ booster/MC as opposed to using the Ford stuff ?

ELLLLLIOTTTTT
10-29-2006, 10:37 PM
BTT... I got an 88 XJ booster but I'm trying to decide which master cylinder to use. Corvette MC?

Jim311
10-30-2006, 08:16 AM
Can anyone commnet on the WJ booster/MC as opposed to using the Ford stuff ?


A friend of mine runs a WJ booster in his XJ. You might search over at NAXJA for some more info about it. He says his 4wd XJ on 33s stops better than his 2WD daily driver Cherokee.

zj95
07-22-2007, 04:22 PM
will a booster out of a 92 xj work?

Alaska ZJ
07-24-2007, 11:16 AM
will a booster out of a 92 xj work?

Yes

gonecheenin
07-27-2007, 11:13 AM
I'd assume those would bolt into a YJ too then?


Any idea which XJ's would have the double diaphram boosters?

adam99wj
08-07-2007, 09:41 PM
id like to know this as well ,

whats the difference between a single diaphram booster and a dual diaphram booster and why did alaska zj swap in the single in place of the dual that was stock in his rig , i would think that the dual would work better

zj95
09-30-2007, 01:31 AM
i got a booster out of a 93 xj and an E350 MC but i dont think they will work...

the 93 has the stupid electric plug on the booster and a really short exactly like the zj booster....

looks like i will be finding another booster... :(

adam99wj
10-25-2007, 10:23 PM
id like to know this as well ,

whats the difference between a single diaphram booster and a dual diaphram booster and why did alaska zj swap in the single in place of the dual that was stock in his rig , i would think that the dual would work better


anyone???

jfowlzj95
10-25-2007, 10:35 PM
i got a booster out of a 93 xj and an E350 MC but i dont think they will work...

the 93 has the stupid electric plug on the booster and a really short exactly like the zj booster....

looks like i will be finding another booster... :(

Hey, you just did this... so far how's it doing for ya? :flipoff2:

zj95
10-25-2007, 10:40 PM
works good...

much better, pedal is nice, and no leaks.... yet

ILikeMud
10-25-2007, 11:06 PM
works good...

much better, pedal is nice, and no leaks.... yet

Really?
I've been thinking about doing it with my latest rig.

zj95
10-25-2007, 11:34 PM
its alot better then i had before... tho it does take some pressure to lock them up


but the thing i like most is the pedal is always the same.
i used a 92 booster, the bolts that go through the firewall were alittle short and i had to shave down the spacer (the one that is on the zj stock that goes between the booster and firewall)

make sure u to install that spacer tho.. i tried goin without it and the brake light switch held the brakes down 1/4 way and got the new brakes smokin on the test drive... haha stupid mistake

ILikeMud
11-06-2007, 11:13 PM
Do you need the little plug that goes into the ZJ booster or no?

Tommy
11-08-2007, 04:53 AM
It's weird, I never felt the need to upgrade my booster or MC. After I did the D60 and D70 swap I took all of the ABS shit out and made some adapter hoses. I need to take some pics. The brake pedal feels like it did stock and I can lockup 38.5's without a problem....

Now my CJ-8 is another story. I plan on doing this..


Originally Posted by Tommy_M
I read your post on the CJ 1 ton brakes. I have a Scrambler with a 60 front 14 bolt rear and it stops like shit. Are you able to lock the brakes up? Whats size tires are you running? And if you have a moment can you send me some pics.


I don't really have any pics at the moment, but I can give you a run-down of the parts I used. Yes, it will lock all four tires easily, and I run 39.5 iroks.

Front brakes are stock gm 1-ton dana 60 rotors and calipers, rear brakes are gm 3/4 ton rotors and 3/4 ton calipers. I have no proportioning valve. Master cylinder is from a '73ish chevy C2500/3500 2wd truck, without hydroboost. This gets you a 1 1/4in bore master and the backside looks just like a stock jeep cj master so it will work with the stock design pushrod. It will bolt in place, however you will have to rebend the lines around to get the fittings in the right holes. Booster is a master power brakes dual diaphragm booster that they sell specifically for the CJ. It literally bolts in place of the original booster and comes with an adjustable pushrod.

Using this setup does two things- the master cylinder gives you the correct volume of fluid when the pedal is pushed, and the booster provides plenty of assist to apply the brakes. It takes about two inches of pedal travel to lock the tires on the street. Takes a little more on the trail in low range, but I can easily stop the jeep in first gear low range coming down an obstacle with little effort. I could probably use a proportioning valve because it does tend to lock the rears just before the fronts lock but I never got around to installing one.

Also, I used a pressure bleeder that attaches to the master cylinder and uses air pressure to force fluid through the lines to remove all the air. All the rubber lines were replaced with -03 AN braided teflon hoses I made by using Aeroquip parts. I think I got everything from Summit and built them to the lengths I needed.

albersondh
05-30-2008, 10:24 PM
I plan on doing a WJ front brake swap into my 98ZJ. I scored an 02 front WJ axle for $50 so theres most of my brake/steering parts. Anyways, I plan on running a MC out of a 99 Dakota. This is a 1 1/8 bore MC vs. the smaller (IDK the actual OEM ZJ size) ZJ MC. From what I understand, the Dakota MC will work with the later model ZJ dual diaphram booster. I have done this type of swap on other junk but this is my first ZJ rodeo, so if someone thinks Im full of shit, or can verify the use of the Dakota MC on a dual diaphram booster please do so. On a side note, I went to the parts store and did a side-by-side comp of the ZJ vs. WJ vs. 01 sport trac rotors and OMFG, the sport tracks are BEEFY and the ZJ's are tiny.

BLK97ZJ
05-31-2008, 12:16 AM
The wj conversion is a shit ton better by itself.

TJeeper
06-02-2008, 04:45 PM
This is a 1 1/8 bore MC vs. the smaller (IDK the actual OEM ZJ size) ZJ MC.

The stock bore in a ZJ MC is 1". By replacing the MC with a larger bore, you reduce the pressure at the caliper. It also gives you a hard brake pedal, which engages sooner than stock. It isn't worth messing around with.

Like I said on the other thread, the 1" bore is perfect with a 48mm dual piston caliper. Lots of people have done this swap and left the MC alone.

Patrick