11" Drums/lines

So, I'm putting 11" drums on the front of the '71. The rear, also, in the near future but, let's concentrate on the front for now. All new brake parts installed on the Dana 27. I bought hardware kits, wheel cylinders and rubber lines for a '74 cj5 (I think I used '74.....maybe '73 or something).

Any who.....I was looking at removing my old rubber lines where they mount on the frame, to the steel line. Read about maybe having to drill out the mounting tab to 5/8 for the new rubber hose's metal end. In looking at this area, I noticed that the new rubber lines will require the next larger size male fitting from the steel line.

The steel lines now on the JEEP are 3/16. It's what I put on when I built it many moons ago. They fit properly for the old 10" drums' wheel cylinders. But at the brass block, on the driver side frame, that splits the lines from the master cylinder to their respective corners, I have adapters screwed in, to go from the 3/16 lines' fittings to the next larger size, machined into the brass block.

So, the question....should I replace the steel lines from the brass block to each wheel with the larger 1/4 line and fittings or, is there a fitting I can get for 3/16 line into the next larger size female part (I think I looked for such a fitting in the past, and found none)?

Are 1/4 lines what belongs with 11" drums?

Oh, and a bit more back ground. I have swinging pedals and firewall mounted master cylinder, all also from a drum brake intermediate. These have been on the JEEP since it was built......and working with the factory 1971 10" drums.

I'll get some pictures to help clarify. It sounds a little confusing as I reread it.

 

Are you sure you have the right part? IIRC all the brake lines on an intermediate are 3/16" diam. except maybe from the MC to the combination valve. Are you using the combination valve from a '74? Look here at fig 9-12. Jeep® 1974 TSM online - two lines to the front brakes, one to each wheel. One line to the rear, and a block on the axle that goes to each rear wheel.

 

I'm with Timgr on this. The lines to the rubber hose and wheel cylinders are, or should be 3/16" id. I have seen some vehicles where the hollow nut that holds the line to the combination valve was larger but the line was the same diameter. Maybe what is going on here? I run into this lots on older Ford trucks ('90's) and occasionally other vehicles.

 

I thought they should be 3/16 as well.

My combination does not look like the one in the manual you linked. Mine is supposed to be for a '71, as sourced from Walck's, used, many years a go.

So, I'm sure my MC was purchased for intermediate (at time of original build), non power assist drum brake cj5. Looks like 1/4" lines should come out of it but, I have it adapted down for 3/16. From MC, the lines go to a combo valve where 1 of the lines gets adapted up to 1/4" fitting (front brakes) and one goes directly in with the 3/16 fitting. The respective lines exit the combo valve the same way-----one adapted back down to 3/16 (to the front brakes) and one, to the rear brakes with no adapter (3/16 line and fitting).

The line for the front brakes then goes to a T fitting to split it to each wheel. All 3 ports on this T are the 1/4 size, machined into the T, and a brass fitting used to adapt down to the 3/16 size for the lines. Everything from there on out remains 3/16, all the way to old 10" drum wheel cylinders.

All the new parts I ordered from Rock Auto were ordered for a 1973 cj5, V8, 11" drum brakes. Just checked my receipt. Drums, shoes, hardware kits, wheel cylinders, and rubber lines.

Camera or computer is giving me a fit. Can't find the pictures I downloaded.

 

So...Rock shows a different P/N for '72-'73 only vs '74+ (and even like '68-75) for the lines. Better check the wheel cylinders, too. Ugh. It just won't end.

Ed.----wheel cylinders are the same P/N '72 on up, V8 or 6 cal.

Edit #2-----Rockauto gives no specifics on the parts. So, i went to AutoZone website. They DO give details. Compared front brake hoses for a 1973 cj5 V8 and a 1974 cj5 V8 since I'm getting different P/Ns for the two years.

1974
Autozone P/N 88245 both ends of hose are threaded 3/8-24

1972
Autozone P/N 70372 male end is 3/8-24, female end is 7/16-24

 

Hey Dave
I had the same problem with my 71.
What I did was use the 3/16th line and the 7/16th inverted flair nut. (Three red one in the kit)
I bought a kit from Amazon called
SAE Brake Line Fitting Kit for Inverted Flares on 3/16 and 1/4 Tube
I used the 1/4" stuff for my return fuel line.
Sounds like you have done the double flairs before.
Hope that will help.
Thanks Dawgy

 

It wouldn't make sense to me to have a 1/4 line from a distribution block to a rubber hose when the supply from the M/C is 3/16. The flare nut may be of a different size with a 3/16 line?