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hard lines for front disc conversion 1966 GTO

3K views 12 replies 10 participants last post by  gtocwp 
#1 ·
Haven't posted in a long time, but just got around to wrenching on my '66 after a long hiatus.

The stock rear control arms were bent, so got tubular uppers and lowers with a swaybar, that led to new springs and shocks, which prompted me to pay attention to the front end for new springs and shocks...then I thought it'd be a good time to do a front disc conversion.

All went well until the disc swap. My car is a power drum with a single reservoir master. I ordered a "kit" from *bay. It spec'd a dual diaphragm booster with a side mounted disc:drum prop valve. The parts looked fine, but the kit was supposed to contain new hard lines (prop-to-caliper lines for RH and LH sides) to plumb the brakes. Lines came with it, but they seemed like stock OE replacement lines in that they were only long enough to get from the caliper hose to the existing old metering block on the inner driver frame rail (which is not applicable in a dual reservoir system). There is NO was they were designed to climb the inner fenderwell up to the prop valve mounted at the master. Short story is I got into a "debate" with the seller that went in circles and returned the kit. Fresh drum brakes for now!

But, in the near future I do want to get away from the single reservoir master and add drop spindles with a front disc kit. Most "kits" claim bolt on, but they do not address the brake line plumbing, which is the hardest part of the job if you do not have pre-bent lines, plus i've never bent lines and don't want to learn on my own brake system.

So, anyone have any recommendations for pre bent lines that are designed to replace the existing lines from my single pot master in my current 4 wheel power drum system?

I've seen these:
1966-67 Pontiac GTO Tempest LeMans Hardtop Valve At Master Power Disc Brake Conversion Line Kit, OE Steel Shopping&gclid=EAIaIQobChMI1rLwkZbB6QIVzz2tBh01hgCVEAQYASABEgIMOPD_BwE​

...but am unsure if they are the right lines and/or what kits they would mate well with. Any info appreciated!
 

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#3 ·
I recently did the disc upgrade on my 66. If I remember correctly I got the preformed lines from inline tube in stainless steel. Some reported issues with the stainless fittings leaking but they were fine for me. I can take a few pictures later today if that would be helpful. I think I got the same master with the proportioning valve from Right Stuff also. Disc brakes were Wilwood.
 
#4 ·
Most kits will come with the lines from the master to the prop valve. Most will not come with preformed lines to the wheels. It's a praticality thing. Hard to ship that way. When I did mine, I bought the kit from Summit and made my own front lines out of CN line. At my shop we do full brake line replacements all day on full size trucks (I live in Maine, corrosion capitol of the world :)). They sell complete line kits for them now, some are stainless. Beware if you go that route. The kits we get have pre-made lines, but they're folded for shipping and have marks where you bend them back straight. The stainless doesn't really like that.
 
#5 ·
Haven't posted in a long time, but just got around to wrenching on my '66 after a long hiatus.

The stock rear control arms were bent, so got tubular uppers and lowers with a swaybar, that led to new springs and shocks, which prompted me to pay attention to the front end for new springs and shocks...then I thought it'd be a good time to do a front disc conversion.

All went well until the disc swap. My car is a power drum with a single reservoir master. I ordered a "kit" from *bay. It spec'd a dual diaphragm booster with a side mounted disc:drum prop valve. The parts looked fine, but the kit was supposed to contain new hard lines (prop-to-caliper lines for RH and LH sides) to plumb the brakes. Lines came with it, but they seemed like stock OE replacement lines in that they were only long enough to get from the caliper hose to the existing old metering block on the inner driver frame rail (which is not applicable in a dual reservoir system). There is NO was they were designed to climb the inner fenderwell up to the prop valve mounted at the master. Short story is I got into a "debate" with the seller that went in circles and returned the kit. Fresh drum brakes for now!

But, in the near future I do want to get away from the single reservoir master and add drop spindles with a front disc kit. Most "kits" claim bolt on, but they do not address the brake line plumbing, which is the hardest part of the job if you do not have pre-bent lines, plus i've never bent lines and don't want to learn on my own brake system.

So, anyone have any recommendations for pre bent lines that are designed to replace the existing lines from my single pot master in my current 4 wheel power drum system?

I've seen these:
1966-67 Pontiac GTO Tempest LeMans Hardtop Valve At Master Power Disc Brake Conversion Line Kit, OE Steel Shopping&gclid=EAIaIQobChMI1rLwkZbB6QIVzz2tBh01hgCVEAQYASABEgIMOPD_BwE

...but am unsure if they are the right lines and/or what kits they would mate well with. Any info appreciated!
Many "kits" seem to need tweaking and often aren't simply a bolt-in replacement. Then when you get the tech guy, he/she really doesn't seem to be of help. This has been seen here before.

Inline Tube is popular and many use them, but the one problem seem most often is the sealing of the stainless steel lines at the fittings. Some say to tighten and release and tighten again to seat the flare - which sometimes work. I suspect the line flares on some ends, like any product, just do not get formed correctly. But, as a reputable company I am sure they can be returned for another set, but costs you the shipping hassles.

I would first email them with exactly what you have and what you are looking to do before buying the lines.

I may be mis-reading your post, but are you keeping the original single reservoir master cylinder, or did a new dual reservoir master come with the dual diaphragm booster? If keeping the original master, not sure why you are not going with a dual reservoir master cylinder? The factory single may prove to be a problem with the smaller single reservoir feeding the larger front caliper pistons. I would also think you want a distribution block so your front disc's don't do all the braking and the rear brakes lock up on you. Just FYI if you are keeping the original master. (y)
 
#6 ·
Haven't posted in a long time, but just got around to wrenching on my '66 after a long hiatus.

The stock rear control arms were bent, so got tubular uppers and lowers with a swaybar, that led to new springs and shocks, which prompted me to pay attention to the front end for new springs and shocks...then I thought it'd be a good time to do a front disc conversion.

All went well until the disc swap. My car is a power drum with a single reservoir master. I ordered a "kit" from *bay. It spec'd a dual diaphragm booster with a side mounted disc:drum prop valve. The parts looked fine, but the kit was supposed to contain new hard lines (prop-to-caliper lines for RH and LH sides) to plumb the brakes. Lines came with it, but they seemed like stock OE replacement lines in that they were only long enough to get from the caliper hose to the existing old metering block on the inner driver frame rail (which is not applicable in a dual reservoir system). There is NO was they were designed to climb the inner fenderwell up to the prop valve mounted at the master. Short story is I got into a "debate" with the seller that went in circles and returned the kit. Fresh drum brakes for now!

But, in the near future I do want to get away from the single reservoir master and add drop spindles with a front disc kit. Most "kits" claim bolt on, but they do not address the brake line plumbing, which is the hardest part of the job if you do not have pre-bent lines, plus i've never bent lines and don't want to learn on my own brake system.

So, anyone have any recommendations for pre bent lines that are designed to replace the existing lines from my single pot master in my current 4 wheel power drum system?

I've seen these:
1966-67 Pontiac GTO Tempest LeMans Hardtop Valve At Master Power Disc Brake Conversion Line Kit, OE Steel Shopping&gclid=EAIaIQobChMI1rLwkZbB6QIVzz2tBh01hgCVEAQYASABEgIMOPD_BwE

...but am unsure if they are the right lines and/or what kits they would mate well with. Any info appreciated!
That’s strange, when I converted mine it came with all the lines and the brakes work great!! Unfortunately it was so long ago I couldn’t tell you what company I bought them from. I do remember it was off eBay. im sure i have the paper work in my folder but it is quite thick and don’t want to go through it unless you want to know where I got the kit. so let me know if you have interest.
 
#7 ·
I used Inline Tube when I upgraded my front brakes to Wilwood disks. I upgraded to the newer style higher capacity master cylinder/proportioning valve at the same time. Only issue I ran into is I wanted to leave the car as manual brakes. While the manual brake master cylinder is readily available (yes, the piston diameter is different), no one makes pre-bent brake lines for manual brakes. I bought the kit for the power brake conversion and had to slightly bend the lines going to the proportioning valve. This did take some time to get right but I was being very careful. I didn't have any issues with the fittings leaking on mine. Everything sealed very nicely.
 
#11 ·
After all is said and done, don't fret over making the 2 front lines. Very easy, you get to make them out of what you want and route them where you want. The small lines from the master to the prop valve are more of a PIA( short and bendy), but virtually every kit will come with those. Unless you do this stuff every day, by far the hardest part of the whole deal will be swapping the spindles. You will like the brakes when you're done!
 
#13 ·
Following a slightly different part of the thread, i too am looking for a good "kit" to convert my 67 GTO 4 wheel drums to 4 wheel disc. Currently looking at Right Stuff AFXD46DSX (11" slotted rotters, power, 8" dual booster, 2" drop spindles, black calipers, e-brake and assessories $1274) and steel brakeline package AOP67H4 ($96.30). AFXD41DSX appears to be the same Kit. I like most of the parts' discriptions, but would prefer multi-piston calipers. The calipers included in the kit are single piston calipers.

I understand i will NOT be able to use my 14" stock rims with this Kit (bummer). I am looking for, but cannot find a Wilwood or Baer 4 wheel disc conversion kit.

Does anyone know of a better 4 wheel conversion option? Should i be concerned about the single pistions?
 
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