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Installed Dual diaphram booster: WOW!

nosigma

nosigma

NAXJA Member # 1371
NAXJA Member
Location
McLean Va
Just got done installing a dual diaphram brake booster and master cylinder on my 92 XJ with 31's. WOW. It can stop now, really stop, like lock up all 4 at highway speed. Very simple installation. Donor was a 95 XJ (booster and master are same as 98 Grand Cherokee but pedal assembly is different) Installed the pedal assembly along with the booster, master and balance bar. Needed to use the drivers side front brake line from the donor vehicle. After cutting the balance bar free of its braket (holds it to the booster) I was able to rebend the stock lines between the master and balance bar so all the stock lines bolted right up except for the front left where I had to use the longer 95 brake line (after some bending). Easy install, parts cost was $45 at local pick and pull. No fooling with rods or metric to std brake line adapters when using the 95 donor parts.

If you have a single diaphram booster and are on 31's or larger tires you really need to do this mod. Its fantastic.

John
 
What year is your rig?

I did this conversion on my Renix. A bit more involved, since thehers a washer fluid bottle in the way. I ended up using a radiator reservoir bottle from a 4 cylinder XJ which fitss between the airfox and fender on mine for a washer bottle. added two external washer pumps, rerouted a few smog pieces and now it works like a champ.
 
What year did they go to the dual booster?
 
Nevada City Sparky: My rig is a 92.

Ghost: 95 was the first year I think. You can also use the Grand Cherokee booster and master but the pedal assembly for the Grand has four bolts to the wall (like all year XJ's) and one bolt that run straight up into the dash unlike all XJ pedal assemblies that have two bolts the run forward from behind the instrument panel into the pedal assembly. This is why you have to swap rods when using the WJ/ZJ assembly, WJ/ZJ rod is not compatible with the XJ pedal assembly. There are already some good write ups on this on NAXJA.

obxtuf: Here are a couple of pics,

first one shows the booster, master and balance assembly shifted down.
DualDiaphramBooster001.jpg


second one show the loop of extra front brake line (using 95 XJ front left hard line). Look closely to the left under the booster.

DualDiaphramBooster002.jpg



John
 
Do you have the s/n from the old brake booster? Id like to see if they are identical to the renix xj model's bendix brake booster. Was it a bolt up, or some fab to the actual brake booster needed?
 
nosigma said:
This is why you have to swap rods when using the WJ/ZJ assembly, WJ/ZJ rod is not compatible with the XJ pedal assembly. There are already some good write ups on this on NAXJA.
Click to expand...

VERY WRONG! Very...

A WJ (I got mine from a 04) booster and rod fits fine. Only mod is to bend up the body seam that runs behind the booster (Very easy) and then to file or grind about 1/16th inch flat at the end of the rod. Just see the stock one next to the WJ and you will Easily see what needs to be done. That with two metric to SAE brake line adapters (10$ total at local parts store).& the rest is just like a direct swap. Not only do you get an even better booster then the 95-96 swap but you also get one thats about 6" shorter.

I highly recommend the WJ booster and master swap in to any pre 94 XJ..
 
the wj stuff is the best
it bolts right it just like robertk said
mine came from a 99 i also had to enlarge the hole in the pushrod so the nylon bushings will fit in.


justin
 
Wait...let me hop in on this thread. So are you guys saying that if I was to get a booster, pedal, linkage, etc. from dual diaphragm year XJ it would all bolt up to my 90 without mods? This is assuming I have everything. Please let me know.
Thanks
 
no pedal!

Just the booster and MC. then you will need to spend about 10 CAREFUL min modifying the rod a small bit. If you have a drill and file your set, well may need a unibit or drill bit. Just lay the new and old side by side and modify the brake light switch hole and flat spot to match your 90. It seriously is easy work!

Other then that you will need to get 2 metric to SAE brake fitting adaptors, and then just bend up the body lip behind the booster. The rest is just removing bolts and putting them back in.

All in all I think it took me by my self about 2 hours and that was with a trip to parts plus to get the adaptor 1/2 way in to it.

Do a search on here for WJ swap and you will get alot more info.

PS this was in my 1990 with a 04 used booster an MC with like 20K miles and I think it was 110$ for the assembly at a yard where they pull it for ya.
 
Is it worth it at all to fit a WJ booster if you already have the dual booster in a 95? Any other vehicles out there that have more assistance than the dual stock booster that will fit with some mods if needed or does space prevent this?
 
Gojeep said:
Is it worth it at all to fit a WJ booster if you already have the dual booster in a 95? Any other vehicles out there that have more assistance than the dual stock booster that will fit with some mods if needed or does space prevent this?
Click to expand...
Not sure on the details but I believe there is an E350 booster swap too.
 
Anyone know if the WJ booster gives any improvement over the original booster in my 2001?

Trying to find something on the E350 booster. I assume its Ford E350 not Mercedes-Benz E350.
 
Thats E350 *master*, into a stock single diaphram booster. You use it if you switch to like a 44/9" setup where you need more fluid by volume, you don't get any extra boost. A few local guys are running like that.

I too have the WJ master/booster in my '87, and have installed the same setup in a half dozen or so 87-90 xj's recently for locals. I get 2004 WJ booster/masters from www.car-part.com for about $60 shipped, $10 in misc parts from the local napa and ~3 hours time. I could lock up 35's with stock brakes and my wj master/booster.
 
Cal, I was wondering if the WJ master cylinder and booster would be the way to go on a 2001 that has Ford 8.8 with discs. I am wondering if the original master cylinder has enough capacity for a four wheel disc setup.

Rachel's 2001 TJ has gained Rubicon rear discs but braking cannot be described as good. I would like to find a solution for her TJ that will also work on my XJ so I only need to keep one set of spares. The brakes are more of a problem on the TJ.
 
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