68 to 69-72 Drum Brake to Disc Conversation
#1
68 to 69-72 Drum Brake to Disc Conversation
I posted this in my build thread but didn't get any responses. Hopefully someone has dealt with this before and can help me out.Trying to install the disc brake hoses to the frame but ran into an issue. The 69-72 brackets mounting holes and indexing holes do not line up. Anyone else run into this problem? Do they make a disc brake hose mount with the mounting hole and indexing hole in the correct place or do I need to drill new holes in the frame for the indexing tab to fit in?
#2
68-72 drum & disc flex lines, frame brackets and retainers are not interchangeable components.
You must match all disc brake components...flex lines, brackets, retainers.
The disc brake flex line has different ends on both sides to include the correct hex & key that keys into the frame bracket.
Source 69-72 frame brackets, flex lines & the correct U shaped retainers, and of course the 69-72 caliper & hardware.
You must match all disc brake components...flex lines, brackets, retainers.
The disc brake flex line has different ends on both sides to include the correct hex & key that keys into the frame bracket.
Source 69-72 frame brackets, flex lines & the correct U shaped retainers, and of course the 69-72 caliper & hardware.
#3
68-72 drum & disc flex lines, frame brackets and retainers are not interchangeable components.
You must match all disc brake components...flex lines, brackets, retainers.
The disc brake flex line has different ends on both sides to include the correct hex & key that keys into the frame bracket.
Source 69-72 frame brackets, flex lines & the correct U shaped retainers, and of course the 69-72 caliper & hardware.
You must match all disc brake components...flex lines, brackets, retainers.
The disc brake flex line has different ends on both sides to include the correct hex & key that keys into the frame bracket.
Source 69-72 frame brackets, flex lines & the correct U shaped retainers, and of course the 69-72 caliper & hardware.
#4
The 69-72 brackets are RH/LH. The 68 brackets are the same on both sides. Personally I would either use the 68 brackets (file the hex hole to fit the 69-72 hoses) or grind off the locating tabs on the later brackets and weld on a new tab in the needed location. You can drill the frame, but I'd prefer not to.
#5
I didn't remember having this issue when I did the conversion young n dumb...back in 85 using a 72 Cutlass doner car.
So I just crawled under it to verify. I think I simply heated and bent the 72s keying tabs flush. Then tighten it up with the metal line and the factory fastener holding it in position. Hasn't moved in 38 years. The soft lines were replaced 20 yrs ago, dam time flies. Prob due again.
Not saying this mod is 100% as I normally do things but....it works. I wasn't 100% back then either...still not.
I think the hard-line geometry may/could be slightly different on 68 drum vs disc. I see the locating hole in the frame just above the bracket towards the front, unless the bracket geometry is that different, Coundnt get under it far enough to operate the cam & light.
Again it works safely.
So I just crawled under it to verify. I think I simply heated and bent the 72s keying tabs flush. Then tighten it up with the metal line and the factory fastener holding it in position. Hasn't moved in 38 years. The soft lines were replaced 20 yrs ago, dam time flies. Prob due again.
Not saying this mod is 100% as I normally do things but....it works. I wasn't 100% back then either...still not.
I think the hard-line geometry may/could be slightly different on 68 drum vs disc. I see the locating hole in the frame just above the bracket towards the front, unless the bracket geometry is that different, Coundnt get under it far enough to operate the cam & light.
Again it works safely.
Last edited by droldsmorland; July 31st, 2023 at 08:48 PM.
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