Anybody have any opinions on brake line size to use on a ch***is with front and rear drum brakes ? I was planning on using 3/16 for my '32 ch***is, then I read something about 3/16" for disc brake systems, 1/4" for drum brake.
It seems to have more to do with what you are running than anything else. GM use 1/4" on the rear feed line, and 3/16 for the fronts. The theory behind that is that the rear feed line is feeding two cylinders, while the fronts are separate to each side. Ford use 3/16 all 'round AFAIK. In short, use what you are comfortable with/have around. Cosmo
You can use either, although the larger diameter will allow more compresion of the fluid, to a point, less pressure from the master to the wheel cyls. It will probably not be something you would notice in a daily driver. Racing applications, (disc/disc, or disc / drum ) 3/16 hard line, and as short of a flex lines as you can use. Personally, 3/16 hard line and #3 braided lines.
I used 3/16 all around on my 'A'. '40 Ford front brakes and '57 Chev rear. No problems hooking it up to the rear, and I used a couple of adapter fittings to connect to the front brake hoses. Works fine so far!
I ran 3/16 on the dragster after running 1/4 and found that it has to do with the diameter on the piston in the master cylinder. To use 1/4" you must have 1" or larger piston and most factory masters are 3/4 so I agree. I am using a 7/8 bore master.
Brakes operate on PRESSURE, and relatively small volume. It doesn't really matter what size 3/16 or 1/4 the tubing is. Either will work fine, but I say go with 3/16 if you have a choice.
I normally use 3/16 if I'm buildin' one from scratch. I've run 'em a bunch af different ways, all drumbs, all discs and discs'n'drumbs. Mine always stop and sometimes from real fast and in a hurry.
Thanks for the input guys. I had already ordered 3/16 when I read the blurb about 1/4, then I started to think about it and the more I thought about it the more I couldn't make sense of it........your clarification has been most helpful. Back to work.
The biggest reason for running 1/4" is looks. Old cars have big brake lines. Especially if we are talking traditional hot rods as in Fords with Ford drum brakes. Another equally important issue is that if you are using Ford 39-48 brakes, the receiving flare in the bottom of the brake cylinder has such a big hole that you may have trouble making a flare big enough in 3/16" to make a good seal, They are made to be used with 1/4"
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