Maverick

I converting my 1971 Cutlass Supreme convertible from power drums up front to power discs .

Do I need to replace my front brake line if they are fine ? I was told by another club member that they need to have a larger I.D.

MDchanic

Never heard of that one.

Far as I know you just have to change the hoses so they fit the calipers.

- Eric

Maverick

I have those. Didn't think I needed to change the hard lines.

Thanks.

Brent

kitfoxdave

there is a little bit of difference between the disc and drum lines... mostly to accommodate the proportioning valve versus the drum brake distribution block. Eddie Hansen used the distribution Block with a manual vale for the rear brakes, may want to check his thread.

brown7373

The lines are different, as are the brackets that hold the lines where they attach to the rubber hoses. The hoses may be different too. The master cylinder also different. Some might say you can rebend or adapt them, but I wouldn't want the lines sticking out and not properly attached and protected on the frame and a arms.

MDchanic

His question was about the diameter of the lines, not the routing.

- Eric

joe_padavano

The line diameters are the same (3/16" for the front brakes, 1/4" for the back). The routing is different, as are some of the flare nuts. GM used different thread sizes on the various lines so they could not be mis-connected on the assembly line. I have rebent the drum brake lines and used inverted flare adapters on disc conversions, though now that I have a flaring set, I just make up new lines with the correct fittings (or buy pre-bent stainless lines).