CJ7 brake booster upgrade issue

marty79

marty79

Well-Known Member
Joined
Dec 2, 2015
Location
Newton, NC
Has any of you used one of these brake booster upgrades on a CJ7 and did it help/make a good difference?
I just finished this LS swap in this CJ and brakes totally suck...like hardly no power brakes and customer says 2yrs ago when he put the booster on he never really noticed a difference then and of course not noticing a difference now either. It sad for last 2yrs at another shop till he brought it to me couple months ago to do the swap and now I'm done but dang brakes are terrible.
Did he just happen to get a booster "bad out of the box"?? thanks for any advise
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he's ok with buying another one if you guys believe he just got a dud or anyone else use any worthy upgrade to help stop all this power he's got now.
 
Jody Treadway said:
What's the issue with the brakes? Spongy pedal or no assist? What axles/calipers are on the CJ?
i.e.- vacuum or hydraulic issue
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all new brake system, calipers lines etc..just hardly no brake assist, unplug the booster and not much difference
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Jody Treadway said:
stock D30/ AMC 20 axles? Rear discs?
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yes stock axles, will be upgrading to one piece chromolly stuff after we get this brake system squared up, thanks
 
rear drums still, all new parts
 
Confirmed your getting good vacuum? Other than a bad booster, wrong plunger size, or proportioning valve stuck out of center, I have nothing to add.
I went so many years with No booster & piss poor brakes, when I upgraded, I went Hydro-vac! If your not used to it, your face will hit the windshield! Stock brakes, disc/drum & 35" rubber.
 

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your plunger depth is probably off. the booster to master plunger requires a specific depth. those kits usually come with spacers

edit: and youre also positive you have no air in the lines? did you do a vac bleed, or old school pumping the brakes while a second open and closes the bleeder?

edit2: wheres your distribution block? is on the fender like oe?
 
ckruzer said:
your plunger depth is probably off. the booster to master plunger requires a specific depth. those kits usually come with spacers

edit: and youre also positive you have no air in the lines? did you do a vac bleed, or old school pumping the brakes while a second open and closes the bleeder?

edit2: wheres your distribution block? is on the fender like oe?
Click to expand...

The booster and master come complete as a set, so one would assume that the plunger would be correct?
 
paradisePWoffrd said:
The booster and master come complete as a set, so one would assume that the plunger would be correct?
Click to expand...
correct, summit racing sells em as a complete unit so we'll see if new one is legit lol
 
paradisePWoffrd said:
The booster and master come complete as a set, so one would assume that the plunger would be correct?
Click to expand...

this looks like a mbm kit. mine did not come pre assembled. mine had various plunger spacers i could add (steel solid cylinders like the size of a pencil). I had to ensure the pedal side had proper travel, and the booster to master had proper travel by taking measurements. They also came in handy when i upgraded the master to the ford e350 one.
 
The new kit should work just fine but back in the day I used a 92 s10 dual diaphragm booster with a 90 wagoneer master cylinder for my 78 cj7 on dana 44's worked great! with stock proportioning valve as well. :beer: poor mans custom power brakes.
 
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