Brakes! Not so standard after all...
 

Been working on the 69 4x4 and going through brake lines now. Of course thinking ahead and ordered new stainless front brake lines for my 4" lift, new prebent lines from in line tube and new master cylinder from frank on the board here. I put a disc brake front end in and ordered everything for a 72 short 4x4 with 4" lift.

First issue, front hoses for a 72 with a 4-6 inch lift are not long enough, Seems odd but i can figure that out. Start laying out all my prebent metal lines. The rear axle lines are not correct, maybe i got the wrong kit?
Time to research... Turns out 70 and older the brake hose went in front of the bump stop which explains why the hoses i returned were not long enough. Relocate them to the 71-72 position and the C-20 lines Special-K mentioned awhile back work good.

Second issue. looks like 72 is the only year that has a different hanger for the rear rubber line and relocating the junction block to the rear end instead of the axle. News to me. Not sure if this is a leaf spring deal, a 4x4 deal or a 72 deal. Looks like my steel lines should be correct now.

Not sure if this has been covered before but figured i would share anyhow. Please add info or correct me if i am wrong on my assumptions.

Pic 1 and 2 are on my 69, 3 and 4 are on a 72 frame.

Re: Brakes! Not so standard after all...
 

The 69 also used a junction block which is different size fittings and won't work for me. Did a disc brake truck have this in 71-72? (pic 1) All my parts trucks just have a brass type junction block like from a hardware store.

Next 3 pics are the 72 parts i am looking for.

Pic 2 shows not even an option for the front brake hose to go in the forward position.

Re: Brakes! Not so standard after all...
 

I can verify that each year 1970, 1971, 1972 are all different when it comes to brake lines/hoses-especially on the rear end.

I swapped everything from my 1972 parts Blazer over to my 1970, because I want front disc brakes, and I had already purchased a 1972 pre-bent line kit.

Those rear line brackets are 1972 only, presumably only for leaf spring trucks/Blazers.

Re: Brakes! Not so standard after all...
 

Brakes and brake lines in general are a PITA. Exactly for the reasons 1970cstblazer pointed out.
They are all different, four wheel drive, long or short or Longhorn, disc brakes and coil or leafs.
Didn't even mention the 1/2 and 3/4T differences. Even the portioning valves are different in style and location.
Even the factory rubber lines, for discs brakes, will not typically fit if the truck was lowered.
I have given up on replacements and just bend my own! I am not confident they were the same even between build locations?
It's crazy all the combinations.

Re: Brakes! Not so standard after all...
 

I don't know if this is interesting or an option for you, but on my 69 2WD truck I updated to disc brakes I bought the front lines for 71-72, and new rear and front-to-rear lines for 69. So the only stuff I changed orientation of was the front, and the rear lines were just freshened up and they just fit. Also Inline Tube, but I opted for steel instead of stainless steel.