YJ proportioning valves changed over the years i think 1991-1995 were the same though. If you have the later style proportioning valve it should work fine with discs in the rear. The TJ's with disc brakes in the rear used the same proportioning valve as later YJ's and TJ's with drum brakes. If you have a Early 1987-1990 YJ things might be different not 100% sure.

 

Second what agalloch07 said. I confirmed this with Blain at Black Magic Brakes.

All this talk of needing to push more fluid because of the rear calipers and needing a bigger bore master cylinder is rubbish. I foolishly listened to all these people and installed the Ford Grand Marquis MC with its 1.25” bore and it did nothing but make the brake pedal effort greater.

The best setup for stock front brakes and the Ford rear end is the 95 YJ 4.0 double diaphragm booster, or modified TJ booster, and the corresponding stock 1.0” bore master cylinder.

 

I have the 2.5L, will this setup still work?


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Totally agree with the above post, the dual diaphragm booster was night/day difference. I picked mine up off Car-Part.com for $65 delivered. You have to make new hard lines from proportioning valve to master cylinder


1992, 4.0,5 spd, BDS 4.5 heavy duty lift, jb conversions ss sye, 8.8 with ARB, Aussie front, tj shafts, dual dia.brake booster, 33” bfg a/t

 

So all you did was add the DD booster? Same MC and prop valve?


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When we swapped mine over to the 8.8 we replaced the booster and the master cylinder with OEM replacements from NAPA just to make sure we were starting off on the right foot so to speak. My YJ stops super quick and it takes very little peddle. The e-brakes are where some of the trouble is with the swap but there are companies that make the necessary parts/cables. It's a huge comfort to know I have disc brakes all the way around and they are working properly. The previous owner of my Jeep did not take care of the rear brakes and it was very dangerous.

 

What year is your yj? So are you on a stock setup, just new?


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1992, 4.0,5 spd, BDS 4.5 heavy duty lift, jb conversions ss sye, 8.8 with ARB, Aussie front, tj shafts, dual dia.brake booster, 33” bfg a/t

 

1992, 4.0,5 spd, BDS 4.5 heavy duty lift, jb conversions ss sye, 8.8 with ARB, Aussie front, tj shafts, dual dia.brake booster, 33” bfg a/t

 

Dual diaphragm boosters were used on 1994 YJ's with anti lock brakes. But they might be different than the 1995 dual diaphragm booster because they have different part numbers. In 1995 dual diaphragm became standard on all 4.0 YJ's and they are the boosters commonly swapped. The 2.5 1995 YJ's used standard diaphragm boosters all of the older YJ's used.

 

 

How much did it cost for new parts? Do you have the part #s


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I'll have to ask Pops, he was the one that changed it all. I'll see him tomorrow evening and can get more info.

 

The cables that came with my 8.8 from the previous owner were these: https://eastcoastgearsupply.com/i-4974616-yj-ford-8-8-e-brake-cables.html I didn't realize they were $100 but they work. Pop had a little trouble getting them installed but they work great and I have no issues parking on a hill.

 

Have this rear in my 1990 YJ. Tried many things to get the e brake to work but still it don't hold.There are a lot of post's online about this problem.I have red that you must use the Motorcraft brake shoes as they are a little softer.I purchased my axle from east coast gear and all the brake parts are new inc park brake shoes and cables,but I am sure they used aftermarket shoes .I will probably try the dealer shoes next (60 bucks or so).I should mention that I had to eliminate my e-brake pedal due to a full cage install and are using a pull handle which puts less pressure on cable but it should still work. Just be ready for a potential e-brake issue.