Best Brake Booster Upgrade

[ValpoManche]

I have been spending a lot of time reading about brake booster upgrades. Everything from WJ to XJ. For those running 31-35 tires on long bed 4x4 setups, lift is not critical; What modifications have you found to work best?  I will also be running rear disc brakes, so this will be an additional factor for performance. 

[ghetdjc320]

If your asking for the best booster out there, hydroboost hands down. As for vacuum boosters, first make sure you have good vacuum at engine idle (min 18hg). A dual diaphragm booster with (2) 8” is similar sized booster plates will work decently. A lot of you braking also comes from your rotor condition, pad material and prop valve setup if your tuning disks.  You master cylinder bore to caliper piston area is also crucial. For stock calipers and ZJ rear calipers, 15/16” bore is great. You can find those on later mode XJ’s. I’m running a 01 XJ booster and MC on my 91 along with a Wilwood prop valve ZJ rear disks and black magic pads with centric rotors all around. After a good pad break in, they work very very well for a rig of this size and weight. 

[cruiser54]

My favorite is WJ booster and master from a JY and grabbing the lines from the master with it.

If rear discs, grab em from a 94 to 98 ZJ. Get the longer mounting bolts for the backing plate also. 

From same ZJ, grab the "guts" from the prop valve and swap them into yours.

 

 

 

[89eliminator]

i put a 96XJ booster and dodge durango master into my 89.  10/10 would do it again.  

[Tex06]

I pulled everything from a WJ and a ZJ a few years back to "fix" my brakes. Never got around to installing it though b/c after I went thru and rebuilt my stock setup, it was way more than adequate.

 

My rear slave cylinders were trashed, one was completely frozen, the check valve on my stock booster was shot, and my pads & rotors up front were beyond worn from doing 100% of the braking. All in all, I think I spent $200 from Rock Auto with new slaves, pads, rotors, shoes, and drums, plus spent $0.48 on a new check valve. 

I've still got the booster if you're interested, I don't see me ever installing it. Can get pics after the holidays.

[ValpoManche]

Thank you guys! I have done the rear ZJ swap on my XJ. So I am familiar with the ZJ prop valve for regulating fluid to the rear brakes. Haven’t done a WJ booster swap and was seeing some different posts on options.  Since I have everything apart on two different MJ’s and a third in process, I am planning on a trip to the local JY and figured I’d get a list together for anything I can find that will upgrade from stock. I may just end up pulling all components from the WJ and also any ZJ’s if they are there so I have parts and pieces to assemble. 
 

@Tex06Ill let you know if I need your parts. Gonna have lots of extra parts when o get these done. Let me know if your looking for anything. 

[Tex06]

On 11/27/2021 at 1:01 PM, ValpoManche said:

Thank you guys! I have done the rear ZJ swap on my XJ. So I am familiar with the ZJ prop valve for regulating fluid to the rear brakes. Haven’t done a WJ booster swap and was seeing some different posts on options.  Since I have everything apart on two different MJ’s and a third in process, I am planning on a trip to the local JY and figured I’d get a list together for anything I can find that will upgrade from stock. I may just end up pulling all components from the WJ and also any ZJ’s if they are there so I have parts and pieces to assemble. 
 

@Tex06Ill let you know if I need your parts. Gonna have lots of extra parts when o get these done. Let me know if your looking for anything. 

Appreciate it. I can easily lock up all 4 with the camper shell on the back so I'm pretty happy for now.