New booster and master cylinder work great (1 Viewer)

nat

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After reading the forums, I decided the reason my 4 wheel disk brakes sucked was the master cylinder bore size. I had 2 instances of trying to panic stop in traffic and my rig kept rolling, fortunately nothing bad happened. I came up with a mid 80's booster and a FJ80 non ABS master from Marlin Crawler. What a difference, I can actually stop now. Thanks everyone.

As a side note, look for pics soon, my 72 pig just got a 350 and NV4500.
 

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Oh...Durka Durka Durka.
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So you were running a 1" drum brake master, or a 7/8 disc master before you swapped?


What is the bore of the master you installed? 1"?



Glad to hear that it is working for you!



:beer:
 
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nat

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I am not sure what the bore size was on my old master cylinder, but it was the stock 4 wheel drum kind, with dual reservoirs.

The one I got is a 1" bore.
 

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Oh...Durka Durka Durka.
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Well, in that case, it was a 1" bore...


Are you sure that your booster was not junk?


I know many trucks with 4 wheel disc set ups that are running the drum master and booster with no issues...
 
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yeah, i am running a '72 drum master, first year with a booster IIRC, and 4 runner calipers up front and the thing stops on a dime. i think my master is 1", i seem to recall finding a '1' on the side of the shaft, but it certainly could be 15/16". i have a wilwood proportioning valve, but it is open all the way...

booster makes a huge difference. mine went bad long ago and i thought it was the master. swapped a few masters trying to solve it before i actually HEARD the vacuum leak from the booster.

good buy on the 80 master though, i hear those are the s**t.


e
 

nat

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I began to suspect my booster was performing poorly when I noticed that in my FJ40 the brake pedal would go down further on start up than in my FJ55. The FJ60 booster has a larger diameter than the stock FJ55, that should yield more vacuum force, which is needed for the larger diameter master cylinder.
 

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stumpy said:
yeah, i am running a '72 drum master, first year with a booster IIRC, and 4 runner calipers up front and the thing stops on a dime. i think my master is 1", i seem to recall finding a '1' on the side of the shaft, but it certainly could be 15/16". i have a wilwood proportioning valve, but it is open all the way...

booster makes a huge difference. mine went bad long ago and i thought it was the master. swapped a few masters trying to solve it before i actually HEARD the vacuum leak from the booster.

good buy on the 80 master though, i hear those are the s**t.


e


1" bore on drum brake master cylinder....thanks man!
 

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