master cylinder brake lines

[liftlawssuck]

79 1/2 ton to 3/4 ton conversion. Which reservoir on the 3/4 ton master cylinder goes to front? I thinking the rear because of the larger reservoir. But just want to make sure. The 1/2 ton is the front. Thanks

[Burt4x4]

AS far as I know the 1/2 & 3/4 are plummed the same way with the single diaphram Vac Booster.
Now the 1 Ton Master & dubble diaphram vac booster they are swapped.
One way to check is go to www.inlinetube.com and look up the replacement lines for your setup. I think 1/2 & 3/4 are the same...I could be wrong.
I went from 1/2 to 1ton here is a pic:

[liftlawssuck]

That's what I thought. I went on RockAuto and checked out master and got even more confused. The 1 I ordered was for 3/4 ton with 13" brakes that looks just like yours. The 11" brakes have a master that looks like the 1/2 ton. The 1 ton section has both looking styles. The ones like we have and the 1/2 ton style but looks bigger. Either way, the larger res is for the front right? I hate looks of that thing but if it will help stop better than it's worth it. I had the 1/2 ton master on there for 10 years with no problems but I'm redoing the truck and figured I'd better match the master to the brakes.

[Burt4x4]

Are you swapping in a new vac booster too? Replacing hte booster will double your stopping "power" a master alone my not be so noticable. But again I went right from 1/2ton to 1ton so?

When I swapped mine out I bought a Master/Booster combo for a 72K30 and new pre-bent lines for the prop valve to master.

If you look at my pic you will see the silver lines from the prop valve to master. The bigger line (front) is for the rear brakes and the skinnier line (rear) if for the front brakes.
opposite of the 1/2 ton setup I replaced.
search this site as there are a buch of threads here talkin bout this...

[liftlawssuck]

I wasn't planning on swapping out booster but maybe I will. Would it give me a firmer pedal?

[Burt4x4]

Before I swapped mine I could only get my 36" tires to lock up in the dirt. After the swap I could skreech all 4 on pavement so yes you'll feel it.

I would buy a master/booster combo 1979 K30. The push rods can vary in size and best to have a matching set. Your prop valve is prolly differnet than mine. But according to all the info I found the lines are swapped on 1ton in 1972...1979 ??

The 1Ton double vac booster is fat so your setup will go forward abit. I added spacer to the support rod that bolts to the firewall to compensate.

[Keith Seymore]

Regardless, the larger reservoir goes to the front system; smaller reservoir to the rear.

K