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Line size out of master cylinder

2K views 2 replies 2 participants last post by  64nailhead 
#1 ·
I'm converting a single reservoir master cylinder to a power dual cylinder setup. It is a 4 drum car. I am using a master cylinder that is designed for front and rear drum. The front and rear reservoir are the same capacity, but the rear port on the master cylinder is larger than the front on the master cylinder. I'm using a distribution block that has one line in and out for the rear and one line in and two lines out for the front. My question is about the line sizing from the master cylinder to distribution block. Should I use the same size line for both? And what size lines should I use? The distribution block is set up to handle up to 1/4" line for the rear and 3/16" for the front. Also, I'm assuming that the rear port on the master cylinder is for the front brakes - let me know if I'm incorrect. The car is a 64 Buick Wildcat with stock drums at all 4 corners.

Hoping someone can help. Thanks in advance - Jim.
 
#2 ·
My question is about the line sizing from the master cylinder to distribution block. Should I use the same size line for both? And what size lines should I use? The distribution block is set up to handle up to 1/4" line for the rear and 3/16" for the front. Also, I'm assuming that the rear port on the master cylinder is for the front brakes - let me know if I'm incorrect. The car is a 64 Buick Wildcat with stock drums at all 4 corners.

Hoping someone can help. Thanks in advance - Jim.
GM typically plumbed the front port to the front brakes, but since your M/C has the same size reservoirs and the same size pistons, it really doesn't matter. GM did use different size lines from the M/C to the dist block - 3/16" for the front and 1/4" for the rear. GM also used non-standard flare nut threads on some of the ports to prevent incorrectly connected lines on the assembly line. The system was designed so that it could only be assembled one way.
 
#3 ·
What you described was how I was planning on doing it also, but I was looking for a second opinion. Also, once I get it installed I was going to do a skid test (15-20 mph and lock the brakes) to see if all of the wheels lock up within a couple of feet of each other. If they don't, then I'll adjust from there.

Thanks again - Jim
 
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