58Mike

If you buy the dual master cylinder from Master Power Brakes, they don't give you the additional brake lines and fittings you need. Someone asked me to list these additional parts, so here goes.

First, brake lines come in two flavors, 1/4" and 3/16". In stock form, a C1 uses 1/4" line from the master cylinder to the front left block (that connector with three threaded holes), then to the front right block. From there to the rear brakes, they use 3/16" brake lines. At each of those front two blocks, there is a third hole which feeds the short 3/16" line to the nearby brake hose for each wheel.

The fittings that go on the ends of brake lines are generally sized 7/16" (for 1/4" brake tubing) and 3/8" (for 3/16" tubing.) If you buy Weatherhead fittings (that's the brand most stores carry), they size them by the brake tube size (either 1/4" or 3/16") rather than by the size of the connector's threads. I find this confusing, but that's how everybody does it. Note also, brake line fittings are called "inverted flare."

The new master cylinder has two connections. The front is 1/2" thread and the rear is 9/16" threads.

Now we're ready to make our list:

1. New 1/4" brake line from the front (1/2") master cylinder hole to the original front left block. The hole we're plugging into in that brake block is 7/16", which is why we're using 1/4" tubing for this brake line.

2. New 3/16" brake line from the rear hole of the master cylinder (9/16" threads) to a 3/16" brake union which we also need to buy. This union will be right next to the original front left brake union we already have. And remember, they call this a 3/16" union even though it's threads are 3/8".

3. New 3/16" brake line that parallels the original 1/4" brake line that goes across the front crossmember. This line connects to new line #2 (the one described in the paragraph above) and then connects to a second 3/16" union at the right front where it connects to the stock brake lines (also 3/16") headed to the rear wheels.

I brought my master cylinder and the blocks to a local auto parts store and they made my lines for me.

4. Two 3/16" brake line (inverted flare) unions. These are the ones I just described in #2 and #3.

5. "The unfindable fitting." We're using the original 1/4" brake line for the front brakes. The original block at the front right has three holes. Since we have a separate brake feed for the rear, we only need two of those holes. I've seen a guy who put a plug in there. That seems easy, but I don't know where you'd get one.

So what I did instead is toss the front right block and look for a new inverted flare union (only two holes) that is 1/4" (7/16" threads) on one side and 3/16" (3/8" threads) on the other side. I dare say it doesn't exist. If anyone doubts it, prove it.

So I cheated and bought a 1/4" female inverted flare to 7/16" male pipe thread adapter (in an L shape, incidentally). And a 3/16" female inverted flare to 3/8" female pipe thread adapter. I slapped some MegaLok (not teflon) on the pipe threads, torqued 'em up good and called it a day.

End of parts list.

Now, some guys will combine line #2 and line #3 into one line and go straight across the back of the engine compartment instead of around the front crossmember for the new rear brake line. This probably works, but I couldn't do it because I did all this with the body off the frame and I couldn't be sure enough of measurements.

Hope that explains things! :)

- Mike Greene

dale3in98

Thanks 58Mike. The exact information I was looking for.

Drummer Boy

Mike,
Try this link.


Thanks for the great Primer on this project. You saved us all a lot of grief.
Let me know what you think of the link.
Eddie

jerry gollnick

Don't forget pressure maintainers, i used 10PSI

jimh_1962

Is that the same as residual valves?

vettebuyer6369

You are answering a post from 17 years ago. Consider starting a new thread.