Break upgrade for renix break system.
 

I've been reading some stuff about a dual diaphragm vacuum booster break upgrade for the old renix break systems. I have a 90 Cherokee and the breaks leave something to be desired. I've been think about a booster and master cylinder out of a 95 or 96 Cherokee, any input would be appreciated. Thanks

I've been looking at this same thing for a couple weeks now, it's supposed to be a pretty easy swap if you get a 96 only some slight modification. I'm heading to the jy today looking for a new cruise control servo and anything else that I could need or want.

A buddy of mine used wrangler parts and had to remove his wiper fluid container, other than that he loves it. I've been reading the same thing you have about the Cherokee swap and it looks pretty straight forward with minimal modification.

Have you thought of doing rear discs? I did them on my wife's XJ and it's great.

She's only got 31s on it though.

[QUOTE=cruiser54;2333423]Have you thought of doing rear discs? I did them on my wife's XJ and it's great.


I would love to do disk breaks

Upgrades best one ive done well worth the little effort it makes 100
% difference ....im running 38s and she stops so good im waiting for axles to snap off and body keep going .

[quote=Asphalt Cowboy;2333524]https://www.cherokeeforum.com/f51/re...-8-25-a-57807/

[quote=cruiser54;2333566]This is on my list also .

[quote=freegdr;2333623]If you decide to do it, snag the mounting studs for the caliper brackets, and the lug studs from the ZJ rearend.

Also, grab the "guts" from the ZJ proportioning valve.

On this note I went to the jy today and found lots if goodies, unfortunately I didn't have the correct tool box with me. If I had the correct one I could have snatched some d35 rear disc brakes.
Also while looking for a 96' booster my friend came across a retired police 03' crown Vic, we were just looking around to see if there were any cool salvageable parts. It was pretty striped by the time we got to it but.... the booster was intact took some pics and I'm curious if I could use it in a my Cherokee. It looks just like the 96' booster but the master cylinder has the hoses coming out on the same side as my 90'.

i converted my renix ABS system to none abs, it was semi pita, i wish i did disc at the same time, my truck stops but it could be beter, i replaced all the brake parts, pads and drum hardware and cylinders and my brakes are way beter then the ABS but are "OK"

i run 35's though

Arm looks the same on the end bolt pattern and dia of booster need to be measured

How big does the booster diameter need to be?

No bigger than what you have now it in a small area there.

Well I can tell just from peaking under my dash that the bolt pattern is about half of what the XJ has so I guess it's a no go. Booster looks the right size

what about just using the crown vic pump?

The Ford booster will fit as long as its the same diameter (no bigger around). The brake booster on the AMC/Renix I'd actually a Ford design. Most use late 80s-early 90s Ford boosters from either Mustangs, F150s or E150s.

Would it be possible to snag the MC from the crown Vic and put it on a 96 booster. That way I wouldn't need to bend the lines?

Just locate correct jeep parts be much simpler to bend a couple of line then mix and match parts in long run.

[quote=cruiser54;2333638]Im grabbing everything from backing plates out when i get to it ...deff .

I'd be bending lines long before I ventured into uncharted waters with a Crown Vic booster.

[quote=freegdr;2344423]I was fortunate when I did mine that I had the complete ZJ rearend on my workbench. Grabbing the studs is easy and saves money and frustration later.

[quote=cruiser54;2344427]Work bench I wish ...lol...

Just picked up a nice metal one for welding. HUGE vice on it from the 50s. $80 at an estate sale.

:cheers:

Well finally did the break booster and master cylinder upgrade… way worth the effort. The old girl stops better than my brothers civic.

Congratulations! What booster did you end up using?

BRAKE booster?

I pulled a booster and master cylinder out of a 95' cherokee. Only mods I had to do was some new break lines from master cylinder to the distribution block and had to drill the hole out on the break booster rod to a 5/8" hole so it would fit on the break petal. I also had to grind the rod flat so it would work with the old break switch.

it's BRAKE, not break... sorry... it was driving me nuts. lol

glad to see you got it done, i did the same thing years ago. well worth it.

Me, too.

I'm glad to hear the 95' BRAKE (I guess that's what we are doing in this thread, lol) booster fits as well, I had understood it was only the 96' booster that needed so little modification.

Did you have the bendix abs system to start with?

Don't matter upgrade still works in place of old Abs or non Abs under powered systems.

my booster came out of a 97+ xj.

i did have to unbolt the brake proportioning valve body from the booster and relocate it down near the frame where my stock one was, only because my stock brake lines only went to there. then just bent the one line with my hand to fit around to the opposite side of my master, and had a new line made up for the rear brake line to master.

and the obvious drill out the pedal rod and grind the end flat.

all in all was an very simple mod and brakes are killer crazy since.

and i still have drums on the rear, no plans for disc swap.

Well I asked because I read somewhere on naxja that the abs pedal assembly pulled thr rod too far out and that you'd have to do a pedal swap if you wanted to get the booster to work.