Booster and brake master cylinder needed

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Aug 27, 2006
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I have a 67 FJ-45 with a disc brake 40 front end now. I need to get a booster and master cylinder for it. What will interchange and work for me. Years, make, model, etc. I have been told that I can use a 77' ish booster from a mini p/u, but cannot use the master cylinder. I already had a booster fabbed to fit up to my pedal and a master cylinder mated up, but then found out that they are both bad! Sucks to be me. The booster leaks air out of the front and the master cylinder will not push fluid up to the front reservoir. Any ideas? Can these be rebuilt? Or back to my other idea as what will interchange and work properly for me. Thanks!!!
 
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Jan 22, 2003
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Kansastitty
How did you deal with the firewall rib? I did not want to cut my rib so I went with an un-boosted GM 4W disc master cylinder. I have a '77 front axle and rear Monte disc setup with 33" tires and the un-boosted master seems to do the job.

GL

Ed
4WDB 001.jpg
 
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Ed,
Was a spacer/adapter necessary to accommodate your GM master?

Have you driven a boosted 40, wondering how yours compares...a buddy has a 65, and wants to go 4whl discs.

Last question, is that your front diff breather zip-tied to your clutch reservoir?
 
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Kansastitty
Ed,
Was a spacer/adapter necessary to accommodate your GM master?


Yes, I made an adapter with the 3-bolt firewall pattern and another plate with the 2-bolt GM pattern. It spaces the master out just far enough so that the rear-most fitting clears the rib, but also prevents me from using the choke pulloff, but no problems, so far.

Have you driven a boosted 40, wondering how yours compares...a buddy has a 65, and wants to go 4whl discs.

No, I have nothing to compare it to, never driven another '40

Last question, is that your front diff breather zip-tied to your clutch reservoir?


Yes. I intend to tie them all together with some sort of a filter on the end......someday;)



Here is a pic of the adapter.
GM_MCyl_Adapter 001.jpg
GM_MCyl_Adapter 002.jpg
 
Joined
May 8, 2006
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I have a 77 brake booster and master cylinder, Works, I ended up using a toyota tundra booster (more power!), I had the original single cylinder 69 master cylinder, then I went up to the tundra cylinder and picked up the 77 booster the day prior, funny how the world works out, Figure out what a fair price is and ill ship it to you if your interested, its the original toyota, non aftermarket, (im in seattle)
 
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Kansastitty
I have a 77 brake booster and master cylinder, Works, I ended up using a toyota tundra booster (more power!), I had the original single cylinder 69 master cylinder, then I went up to the tundra cylinder and picked up the 77 booster the day prior, funny how the world works out, Figure out what a fair price is and ill ship it to you if your interested, its the original toyota, non aftermarket, (im in seattle)


How did you fit the booster? Mark A has an adapter that spaces the booster out from the firewall to clear the rib.......or did you just cut the rib?
The rib is the problem with fitting a booster.

Ed
 
Joined
May 8, 2006
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I had the same problem with the three bolts to four bolts, as for clearence I have a sbc with custom headers that left maybe an inch of space if that when I mocked the thing up, I presume you mean your problem is the rib on the firewall and the three bolt to four bolt, , the rib can be taken care of with an oxyexcetiline torch (it helps to have good friends), then pounded down with a hammer and smoothed with a grinder (Its a show car shockingly), as for the three to four bolt conversion, i thought about the adaptor and thats completly dependent on your header setup as to weather it will work or not,

I took the same torch and cut a bigger hole, then drank a six pack and grinded the remaining to make a slightly larger hole, then I drilled four holes around the circle to fit it, (be precise and not drunk becuase otherwise you can really really fxxx up when you do this. so cut circle hole slightly bigger then rubber boot (yes you want the stinkin boot!), drill the four holes (its even the same bolt size as your original!), and mount, then assuming a huidini position bolt in three or four of the bolts from behind your dash (what can reasonably be accesed), try and figure out before you mount the booster setup as to where the pedal has response and align up the pole with the pedal, then painstakingly reajust everything and benchbleed, then bleed, drink more, then afterall is said and done adjust each cylinder (if drums are still present) to prevent lockouts) (buy a brake adjuster- the nob type, not the lever!)- good luck, oh, and for the rib, dont try giant tin snipps or sledgehammer. the otrch is the only way to go

(afterthought- protect your wires when using the torch!)
 
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Aug 27, 2006
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I used a die grinder with a cut off wheel. Pretty clean looking. I will try a mid 70's mini truck booster and master, that had the front disc brakes. I will make my own plate to use the 4 bolts.
 
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May 7, 2006
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erie pa
i cut the rib used a mini truck booster and 75 master cylinder with a 1" bore on my 69 and 70 because i had them . they work good unless your fussy good luck
 

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