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anthonyh75

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Discussion starter · #1 ·
I have a 98 zj 5.9 and my brakes suck. I have put on stainless steel brake lines performance friction z rated pads and I still cant lock up my brakes. I have 265/70/16 tires on but it should still lock up the brakes. If it is wet out I can barley get the abs to activate. I have also changed the fluid and bled the brakes. Any suggestions would be great.
 
anthonyh75 said:
I have a 98 zj 5.9 and my brakes suck. I have put on stainless steel brake lines performance friction z rated pads and I still cant lock up my brakes.
It's called ABS. It's designed to prevent you from locking up. Is there a reason you want them to lock up? ZJ brakes suck, at least you don't have drums in the rear, like I do. If it really bugs you, search for Kung fu brakes by AlaskaZJ on POR, or spend $4,783,628.85 on Porsche 911 brakes for ZJs.
 
ofcoarse we all know I did the Kung Fu....or is that Wang Chung?

I can lock up a 36 up to around 45mph. Never had the balls to grab them that hard faster than that.

Here is a writeup I did a million years agon.

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

It totally gets rid of everything ABS. But I like it that way. A friend of mine used the ZJ booster and a Dodge 3500 master. He likes the added pressure of the double diaphram.

Personally I just press on the brakes harder. I like the extra control of the stiff pedal.

Keep Jeepin
 
What about if you want to have to have ABS? Here in PA, if the car had ABS and you disable it or it does not function, you will fail inspection (ask me how I know). If you get pulled over and the officer see's that you have the ABS light on in the dash, he can ticket you for driving an unsafe vehicle (ask me how I know).
Besides I like havind ABS for when my wife drives the jeep or I have the kids with me.
 
93/5 speed said:
What about if you want to have to have ABS? Here in PA, if the car had ABS and you disable it or it does not function, you will fail inspection (ask me how I know). If you get pulled over and the officer see's that you have the ABS light on in the dash, he can ticket you for driving an unsafe vehicle (ask me how I know).
Besides I like havind ABS for when my wife drives the jeep or I have the kids with me.
If you have to have ABS then don't do this mod.
 
I totally dig the Kung Fu brakes (I have the E350/XJ setup), but personally I would never run it with the ZJ brakes. I know like Alaska runs a 50/50 combo but its a trailor queen and the normal ratio is far more in favor for the fronts and Im going to keep it that way on the road. The ZJ calipers are pretty small and I feel they have a hard enough time with the stock power the booster/cylinder provides. Add in the extra weight of a built rig and that extra braking power the Kung Fu provides and just seems like your exceeding the limit. Guess there isnt and big evidence supporting this, Im just paranoid.

I originally picked up some 1/2 ton Chevys for my 44, but besides being bigger they looked pretty similar. Im returning them and Ive picked up some 3/4ton Chevy dual pistons instead. I think the Kung Fu brake system will work very well with the massive dual pistons and Exploder rear calipers.
 
So if I keep the factory ZJ booster, you would get more pressure than switching to the XJ booster? Does it make the pedal harder to push or easier? My wife isn't very big and I would worry about the addition force required to push the pedal with the Ford or Dodge MC.
Nathan
 
Nate if you keep the double diaphram booster it will make the pedal easier to push. Buddy who did the 3500 swap said that the pedal pressure was about the same but the clamping pressure was greatly enhanced.

My wife is on the strong side (3 years Army and 3 years College and International sports, current Airforce wimp though) and she absolutly hates the brakes in the chuggy. She said that it just takes way to much pressure to get the brakes to really grab hold.

I don't really notice. But then again I am 6'3" and 270 with an above average leg streangth.......Trango is a pretty big dude (his wingspan is 6' 11") as well so he might be in the same sort of situation....

Food for thought and a honest opinion.
 
Would this kung foo thing fix the issues I've had since upgrading to larger calipers up front and adding disk in the rear? The way it stands right now I can brake OK but occasionally the brake light comes on and I have too much travel in the pedal (not air in the lines either). I'm thinking it's because of the increase in volume needed because of the newer calipers. I've though about trying to swap the master cylinder. Thoughts?
 
If I am not mistaken, the ABS was designed to work with stock sized wheels. Something to do with the revolutions per mile count. Going up in tire size reduces the wheel RPM which can play havoc on the ABS. It is designed to pulse so many times per second to stop the vehicle. That same number of pulses on larger tires means a longer stopping time so it does not sound like ABS with bigger than stock tires is all that safe. My guess is up to 31's you are not adding much more in the circumfrence of the tire but say 35s like Alaska ZJ has it adds quit a bit and your stopping would just plain suck. You are way outside of the design criteria window.

Bigger tires need bigger brakes in order to stop.
 
Nate- I think that the newer dodge 3500 masters mount the same way as the stock ZJ master. In my writeup there is a picture of the ZJ and E350 master in the same pic. You can surely see the difference.

Bulldog- I have Q78 tires. bigger than a 35...lol
 
Discussion starter · #18 ·
So is there a MC that will bolt right in with out changing anything else and give me more stopping power? Is it possible that my old one is just worn out some?
 
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