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Bigger master cylinder options? (searched)

88K5Jimmy

1/2 ton status
Joined
Jan 10, 2001
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Location
Tulsa OK
Right now I have the stock 1/2ton brake system, with disks in the front and drums in the rear. Would it be a worthwhile mod to upgrade the 1/2 ton master cylinder to a 3/4 or 1 ton? I don't want to do hydroboost or rear disks at the moment so all that stuff is out. Basically, do the internals of the 3/4 and 1 ton stuff push more fluid than the 1/2 ton stuff? Or are there any other options such as aftermarket master cylinder systems?

Thanks
Ross
 
one tons wont fit a stock half ton booster..we put a 3/4 ton on my buddies, combined with the rear disc setup on the 14b, it stops really well, of course the old master was leaking and all that crap so...
 
K30 booster and K30 M/C.

both of yours will be tired, so a upgrade would be a good idea as preventive maintenance too.
 
I have the stock 1/2 Autozone $17 rebuilt master on my truck with the AZ Kicking rear disc kit. Firm peddle and no problems stopping 35's even with 2,000 lb of trailer behind it that doesn't have brakes. .
 
If I was to replace my MC with a 3/4 ton, what year truck should I ask for? Somewhere in the 80's? What about replacing my stock MC and booster with a 1 ton MC and booster? What years should I ask for in that? Also, is there a larger piston or something inside the 3/4 and 1 ton stuff that makes them better? Will my brake lines fit the new MC either 3/4 or 1 ton?

Thanks
 
I put on a 3/4 ton MC and I just used the same year as my truck. I don't know if it is any better than the 1/2 ton, but it bolted up the same, lines all fit. The only difference I saw was that the reservoir size was larger. It was only like $17 so it wasn't a big investment either.
 
What is your goal in swapping MC's?

Do you know that a larger bore MC will make braking harder?

It will also make the peddle firmer and higher (when you stand on it)

What is the bore on a 1/2-ton MC?
What is the bore on a 3/4-ton MC?
What is the bore on a 1-ton MC?

Enough questions how about some answers...

All '79 w/ 350 engine. Info from www.napaonline.com

1/2-ton
Bore Size: 1.12500''
Line Thread Size: 9/16-18, 1/2-20

3/4-ton
Bore Size: 1.12500''
Line Thread Size: 1/2-20, 9/16-18

1-ton

w/ Hydro-Boost
Bore Size: 1.31250''
Line Thread Size: 9/16-18, 1/2-20

Bore Size: 1.12500''
Line Thread Size: 1/2-20, 9/16-18
w/ Vacuum Booster

As you can see going to any other MC other than a hydro-boost will not do a thing for you.
 
I was just trying to get a MC that would push more fluid. However, looks like without a bigger piston in the 3/4 and 1 ton stuff I'm not gonna gain very much. I think I have air in the MC or close to it cuase the brake light comes on and I have a crappy feeling peddle, real squishy and doesn't feel like the truck is going to stop. Probably just need to bleed the whole system again.
 
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