Front Disc Brake - Master Cylinder Question

[tcb-1]

I'm getting ready to do a front disc brake/lowering spindle conversion on my '69 C-10 1/2 ton. the kit I am buying from GMCPaul's does not contain a master cylinder/proportioning valve. Keep in mind, I'm not going to use a power booster.

1. I will be replacing the original drum/drum master cylinder anyway, so I'm wondering will I need to replace with a 71-72 disc/drum brake master cylinder?

2. I suppose I won't be using the original proportioning valve since it's a drum/drum, correct.

3. OR, can I go back with original drum/drum master cylinder and install an adjustable inline proportioning valve and tweak accordingly??

Thanks for you help guys!!

[Eichorst69]

You have to use the disk/drum master and proportioning valve.

If you're not going to use a booster it may be better to get an adjustable proportioning valve???

Rob

[70C10Step]

I am doing the same swap right now. I bought a disk/drum proportioning valve on ebay last night from CPP auction Item number: 290169853812 for $39.00. They still have 4 left on this auction. I went to Kragen auto parts this morning and ordered a 72 c-10 master cylinder for $18.00, $10.00 core charge. I am using disc brakes off a 72 C-10. I basically copied my friends 71 c-10 setup with manual disc brakes.

[lolife99]

tcb-1,... any reason why you don't want a booster? The braking "effort" is so much nicer, and gives a more confident pedal "feel". Also,... (and this is just me),... I like the original look. On my blazer I used all reproduction hard lines and it made things easy. Check out ECE starting here http://www.earlyclassic.com/catalog.aspx and then get some standard or stainless lines from Classic Tube, Inline Tube,... or who ever. I think you will like the power booster.

[tcb-1]

Originally Posted by lolife99

tcb-1,... any reason why you don't want a booster? The braking "effort" is so much nicer, and gives a more confident pedal "feel". Also,... (and this is just me),... I like the original look. On my blazer I used all reproduction hard lines and it made things easy. Check out ECE starting here http://www.earlyclassic.com/catalog.aspx and then get some standard or stainless lines from Classic Tube, Inline Tube,... or who ever. I think you will like the power booster.

lo,
I will eventually go with a booster, but this a budget build and each little dollar I can save is going to be worth it. doesn't help that my wife is an accountant!!

so for now, we will just strong leg it. guess all these years of squats in the gym will pay off!!

I found a company that produces the proportioning valve bracket and the prebent lines, so at least that is done.

gotta get over your way sometime!!

[PanelDeland]

tcb, who are you getting the lines and bracket from.I am doing the same swap but with power.I have an adjustable proportioning valve but would like to find prebent lines.It's been years since I double flared any lines and I want it to work.

[tcb-1]

Originally Posted by PanelDeland

tcb, who are you getting the lines and bracket from.I am doing the same swap but with power.I have an adjustable proportioning valve but would like to find prebent lines.It's been years since I double flared any lines and I want it to work.

here you go, Panel!

http://www.performanceonline.com/sto...cat=665&page=1

[70C10Step]

Thanks for the tip. I just bought the bracket and lines also...

[PanelDeland]

Thanx tcb 'preciate it.

[Longhorn Man]

the option of booster/no booster would have nothing to do with having an adjustable valve. The hyd side of the equation still remains the same.
However, if you wanted to fine tune your brakes, keeping the old distribution valve (it wasn't a proportioning valve till 71) and adding an adjustable valve on the line going to the rear brakes is a very good idea, esp if you plan on having bigger tires in the rear.