I need to install brake lines, MC, and prop. valve. Help!

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J

Judge Mills

1971 Plymouth Duster
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I have a 71' Duster that was originally had a /6 and 4 wheel drums. It now has a 318, 73' discs in front and a Ford 8.8 in the rear with discs. I now need to run all new brake lines, install a new master cylinder (since the original one is not power assisted) and install a proportion valve. Any help on size of brake line, which master cylinder to install, and which prop. valve to purchase would be great!

I would assume I want power brakes, right?

I want all new line since I'm sure the old lines are not in great condition.
 
well in line tube makes a reallly nice set and i would say surf the net for info on the master i am not sure which one would fit your. after you find out which one fits hit hte bone yard and buy it used
 
you may even look at some chevy mini haves and get the hyrdo boost brake system out of it that would be the all of it master cylinder hydro boost rod hoses and try that if it is any thing like my truck
 
I've seen a couple different things on this board. If I am thinking correctly, a few have used the MC from a 80's or 90's Caravan. Enough people have done the 8.8 swap on here, but I have noticed quite a few haven't changed the proportioning valve, which can't be a good thing.
 
I guess my most pressing issue is I don't know what size of tubing to buy for the brake lines. What size is the line on the '73+ calipers?
 
In Line Tube has an atrocious web site. Might be good stuff, but really hard to navigate their site.

I am debating bending my own line, or going pre-fab. Problem with Prefab is that they may not line up with the new MC and I'd have to hack on them for the new rear axle.
 
Judge Mills said:
I guess my most pressing issue is I don't know what size of tubing to buy for the brake lines. What size is the line on the '73+ calipers?
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Should be the 3/16th (I think that is the size); basically standard size brake line available pre-bent from places like Fine Lines; or in sections from the parts stores or in 25 foot rolls.

Judge Mills said:
In Line Tube has an atrocious web site. Might be good stuff, but really hard to navigate their site.

I am debating bending my own line, or going pre-fab. Problem with Prefab is that they may not line up with the new MC and I'd have to hack on them for the new rear axle.
Click to expand...

For the rear axle, maybe Fine Lines or In Line Tube will have pre-bent lines for your 8.8 w/disc brakes application. They might even have lines from the M/C to the proportioning valve.
 
I would think the stock drum brake distribution valve should work just fine. All it does is send fluid to the 4 brakes. For the rear you will probably need to add an inline adjustable proportioning valve. Just buy your line buy the roll and make your own. We do it all the time on the cars we restore.
 
One more tidbit, possibly relevant: A disc/drum master cylinder might have a residual pressure valve in the outlet to the rear brakes (they definitely did up through 1972, at least). You don't want this. More recent cars had this built into the rear wheel cylinders, so the MC would be OK, but you need to check the application. Disc/disc master cylinders would of course, be fine.
 
Many people use a manual MC with disc brakes (search posts), it depends on how strong your leg is. Seems most prefer a 15/16"D MC. A smaller bore (7/8"D) will give less effort, for more pedal travel. You sure don't want the pedal bottoming out on the floor, but usually not a problem if you get all the air bubbles out. Look on rockauto for specs. I recall seeing a Volare MC with 1"D for manual disk brakes, but their pedal might have been different. Are you sure your body lines can't be re-used? In my CA cars, what looks like rust is usually more like baked dirt and they cleaned to shiny real easy. I think all brake lines are 3/16"D, even newer "bubble flare" ones spec'ed in mm. The only difference I have seen is the 1/4" tube from the single pot MC in Mopars before ~1967.
 
I"m not 100% sure if the lines themselves are rusty, but all the connections are. I live on the Washington coast, so even 4 year old cars are rusty underneath!
 
I bought a set of brake lines from inline tube. I had to mess with one spot a bit. other than that they were okay.


Later on down the road i learned how to bend my own brake lines and flare the ends. Honestly If I had known it was so easy I would have never bought pre bent lines.

I think since you aren't using stock stuff you'll be best off bending your own. Use your existing lines as a template where necessary.
 
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