brake lines

[harrybar]

I am in the process of restoring the brakes on my 68 Commando, which did not work very well since I bought it in February. The brakes are the original 10" and the wheel cylinders are the Wagners, which I just replaced. I noticed the line from the master cylinder that was suppoosed to go to the rear actually went to the front brakes. And, the size of the lines coming from the master cylinder were different diameters, with the larger line going to the rear brakes. Can anyone tell me what the diameter of the lines should be coming from the master cylinder? And, do I need a proportioning valve? The master cylinder is a dual. I would think this would regulate the front and rear pressure, but I don't know for sure. My factory service manual just shows the front line going to a tee connector as well as the rear line.

[jpflat2a]

not real sure, but I think the lines that come from the master cylinder should be of the same size as the rest of the Jeep. They also should terminate at a 4 way tee, which then has the lines that run to the axles, where you again should have 2- 3 way tees, which direct the lines to either left or right side of the veicle.
I see no purpose of a larger metal line going to the tee, than a smaller diameter line continuing from there; pressure is pressure.
I am not a hydraulic engineer FYI.
as I recall, no proportioning valve used on your Jeepster with 10" brakes

[rich45]

I not sure that this will be of any help at all but the lines on my master cylinder are the same diameter- the one from the rear of the master cylinder goes to a block near the frame and is on the inside(right side as you look towards the fire wall) while the line from the front connects to the block on the left side.I believe this block is just a connector . I did my cylinders about two years ago and wasn't real impressed-but mine has had to sit and has not been driven for a while.I'm told the fix is a brake booster which mine does not have-supposed to make a big difference.At any rate good luck with your 68-mine is the same year so if you want me to look at anything on mine to compare let me know.

[Pack Rat]

Front lines are 3/16th, rear are 1/4" although I've seen them where both lines are 3/16th but if you have 1/4" to the rear I'd stick with that. No proportioning valve, just that 4 way Tee to the rear as mentioned. Short of upgrading to 11" brakes front and rear or converting to disc, power brakes is THE way to go. And that's true even if you have 11".

[Boyink]

Short of upgrading to 11" brakes front and rear or converting to disc, power brakes is THE way to go. And that's true even if you have 11".

IMHO I wouldn't do power before getting rid of the stock brakes, and based on having both power and non-power 11" setups feel the 11" non power is plenty of stopping force..

Not sure I'll put the power setup back on the 6.

[vanguard]

On my '65.

The original single circuit MC had a larger diameter line (1/4") running to the 4 way block and three 3/16" lines running from the block. One to each front wheel and one to the splitter on the rear axle.

[harrybar]

I really appreciate the replies. I just put in the new master cylindler and I put the line going to the front brakes to the port marked "front" on the MC. The lines were going to the wrong ports before. The lines are 3/16" and 1/4" with the larger going to ther rear. I'm sure glad that is correct. Tomorrow, I'll bleed the brakes and take it for a spin. I already replaced the 10" shoes and 1" bore wheel cylinders in the front, so I'm not too anxious to upgrade right now.