Brake Line difference between Manual and Power

[Rocketir]

I was looking to replace the hard lines and there is a different part number for Powered Brakes vs. Manual brakes. Is the only difference the location of where the lines meet the Master Cylinder? Or is there a size difference between the two? Reason I ask is I'm leaning towards manual brakes, just for the looks. But may transition to Hydro Boost if I am not happy with the feel. Currently I have stripped the truck and there is no lines/booster.

https://www.inlinetube.com/collectio...20Steel|Front|

[72SB]

FWIW when I converted from manual to power brakes on my 72, the manual lines all threaded into the new PS distro block.

My sense is there is some slight bend difference between the two but either could be easily massaged to work manual or power.

[Rocketir]

I was thinking its probably only the actual routing that is the difference. Thank you for sharing your experience. I will probably go with the Manual P/N.

[dmjlambert]

I converted from manual all-drum brakes to manual front disc brakes and rear drum from a 1971 donor. I am sure glad I did that, manual brakes on my CST/10 has a great brake feel and does not require much pedal effort. It took research from members 54blackhornet, Keith Seymore, and several others to figure out the master cylinder specs and part availability. https://67-72chevytrucks.com/vboard/...39#post9169739
As far as i know, nobody has concluded on factory brakes how far from the pivot of the brake pedal lever is the attachment for the push rod and if it is really different for power vs. manual.

[70STOVEBOLT]

When I converted all drum system from manual to power, all I did was add the booster. Didn’t even unhook the lines, just carefully moved the master cylinder forward and bolted it to the booster.

[72SB]

while using the smaller bore manual brake MC will "work"....All power brake setups used 1 1/8" bore MC. The smaller manual bore would require more braking effort and longer pedal travel....but will otherwise "work" if that is good enough for anyone's liking.

[dmjlambert]

Power and manual disc brakes are both 1 1/8 bore. The amount of pedal effort and travel is trivial to me on 1/2 ton truck with manual brakes, so much so that I wonder why people are so interested in power brakes.

[72SB]

drum brakes are 1" bore MC. Front Disc brakes are 1 1/8 MC.

front drum
https://www.rockauto.com/en/moreinfo...JEJD5RsPMwLpyp

\Front disc
https://www.rockauto.com/en/moreinfo...JEJD5RsPMwLpyp

[dmjlambert]

Thanks, I edited my post above; I should have said 1 1/8 bore is for both power and manual disc brakes (71-72).

[70STOVEBOLT]

Originally Posted by 72SB

while using the smaller bore manual brake MC will "work"....All power brake setups used 1 1/8" bore MC. The smaller manual bore would require more braking effort and longer pedal travel....but will otherwise "work" if that is good enough for anyone's liking.

I didn’t notice a difference in pedal travel, but the braking effort (leg force) was decreased due to the vacuum assist provided by the booster.