Disc swap - Soft hoses to front or leave in back?

[May70]

Lets see if I can keep this straight:
1967 C20 Frame, control arms
1977 C20 spindles, hub/rotor assemblies, calipers

1967 had the drum brake lines on the back side of the upper control arms
1977 had had the disc lines coming up to the front of the upper control arms

I saved the original soft lines from the 77 to compare/test fit. The banjo bolt (that came with new caliper) is too big to go through the square interestingly, im not sure why. Not sure if ill have to figure out a different part number. I did buy new calipers and I cant seem to find the old 77 calipers to compare.

Basically my question here is what's the best route to take the soft lines? I'm thinking about following the 77 routing ill just have to see about drilling out holes on the front of the control arms and potentially reusing those clips. Not sure if new lines come with those or if my banjo bolt and block hole size gets cleared up. Pics would be great.

Thanks

[May70]

Post for my records (& others). Still looking to find pics of how others did it. I may go out and buy both to see how I like it.

https://67-72chevytrucks.com/vboard/...ake+conversion

Originally Posted by Accelo

"Have you had any issues the the routing of the brake lines behind the a-arm vs in front as the factory did for the 71-72 trucks."

I believe you could go either way, in front or in back of the cross member.
The easiest way is to use the rear lines like factory drum brakes.
One important reason to use the rear lines is your cross member doesn't have the clips needed to retain the hose in the front. To go with the front lines you need to add this clip. You need to purchase the lines and installing them under the motor mount is no easy job with a motor installed.

Most conversion kits would reuse the existing lines. (If indeed they planed anything). From the factory the 3/4T truck required longer flex lines than the half ton. I went through three sets of hoses till I found one that would work and not rub. And yes I PURCHASED A KIT that came with lines. I swear unless you purchase a high end kit like Wilwood's Bolt-On and Conversion Brake Kit it's going to take some work and some luck.

I see you have read and commented on the post about the rear studs.

The job is a PITA but it's worth it. The job is lots easier with quality kits.

Rick

[SkidmoreGarage]

I have this setup (67 with 77+)

The soft line runs on the rear of the control arm using a stainless braided line.

I think this is the best option if you don't plan to replace everything. As the post you made above pointed out, moving to the front will require modifying how the existing hard line routes. This isn't that difficult, but your post makes me think that it isn't your first choice.

While it may work, I would not use a rubber line. The angle and length of the soft line means that it will likely contact the wheel or control arm at some point. It's nice insurance to have a braided exterior for abrasion resistance.

[kwmech]

When I did my conversion in my dually I kept the lines in the back. It was easier than going behind the frame rail, shortening and reflaring the line for the front. The bolt issue is you have a 7/16 bolt in your hand and have 10mm hole in the line. What thread is the caliper?

[Grumpy old man]

This might help .


https://67-72chevytrucks.com/vboard/...d.php?t=818077

[GASoline71]

You don't want that bolted to the upper control arm like that. It needs to be tied in at the crossmember.

Here's how I did mine when I swapped 1972 stuff over to a 1969 frame.

http://67-72chevytrucks.com/vboard/s...&postcount=157

Gary

[bry593]

I'd run it like the factory did for '67-72 C20.

The real issue is that none of the reproduction hoses fit a C20. You might think they do, but at full lock and droop, the hose is stretched to the max.

I paid to have my original hoses custom reproduced. They reused one of the square pads at the caliper, but had a NOS fitting for the other side. Cost me a bill, but at least it works and fits like factory....

[71meangreenc10]

I have seen two "rubber lines to the rear" converted trucks brake lines fail. Just as Bry593 stated above, the lines when going lock to lock get stretched and separate. One is a member here who was lucky to have his brake system fail in a parking lot and was able to prevent an accident from happening. I actually hauled his truck back to his house on my trailer. In the past when I convert my front drum trucks to disk, everything gets swapped over to 71/72 style. I order my lines from inline tube and then change the master/valve to meet the same model. I have not done a deep dive into why this is happening on the failing parts, but I have never had an issue doing it the 71/72 way. I am trying a 73 style on this 68 stepper since the crossmember came out of a squarebody. Not a fan of the valve location for the squares that is for sure. The truck is down to the frame so it is easy to overhaul components at the moment.

Smitty

[May70]

So I decided to pick up the Duralast 88466 hoses from AutoZone and the 1977 C20 spec'd hoses from O'Reilly Part numbers (BH86550 / BH86551). That way I can put both on and just see how they fit. By the way both styles use 7/16" banjo bolts - so that problem is resolved.

These are the pics with the short Duralast 88466 hose which some members are using in the rear mount location. I did not like this at all so I ended up choosing the 77 style. There was way too much contact and I dont like the way it has to double back. I would not recommend that at all, the 77 style is way cleaner. Also I know the squarebody routes the brake lines to the front side of the cross member originally but I think ill just run the lines back to the rear of the cross member. Routing TBD.

[May70]

Drilled out the hole like the 77 has in the upper control arms and installed O'Reilly Part numbers (BH86550 / BH86551). Much happier with this - zero contact and the hose isnt bending back over itself.