I have a complete front disc brake setup from my 68 Lemans and am wondering, if it will fit my 66 Skylark. Right now the Skylark has drums with a single cylinder power brake. Can anybody tell me if the parts will interchange (couldn't find any info on this special combo), what parts too take and what the problems will be? Thanks Dan
Yes, it will fit, spindles, brakets, all of it. You will need the master cylinder (or some dual bowl master), proportioning valve, brake lines. You can use every piece from the 68 LeMans if you want, it will all work on the 66. Some of the differences are; the prop valve or distribution block are in a different place so the lines on the 66 are different lengths than the 68, and the line going to the rear brakes will be longer on the 66 than the 68, so you will need to shorten the 66 one or change it to the correct one, the 68 may work. I'm doing this to my 66 Cutlass right now. I bought a changeover kit. So I know what is different on these. I didn't use the new valve nor master cylinder that came with the kit. I bought some 67 Cutlass reproduction parts to use so it would look like GM parts. I also bought a stainless line set and am changing everything. I will sell the parts I didn't use if you are interested. Send me some pictures of the 68 Lemans parts, master cylinder and prop valve/junction block, is it still on the car or all off? My email is listed in my posts. Mike
That sounds good, thanks. You can see the master cylinder and the prop valve on the attached pictures. The parts are now off the car.
The parts you already have are the parts I bought to use on my car!! The valve under the master cylinder is a hold off valve, it is in the front brake system. It holds off the front brakes so the rear ones can "catch up" with the front ones. The block down on the frame is just a junction/distribution block, it is not a proportioning valve. This is just how the early systems were. GM didn't have a proportioning valve until 1971. You can use this website to learn about the different systems http://www.inlinetube.com/ , just don't let it confuse you. MOST of the front disc changeover kits use the 71 up prop valve. They give you a bracket which mounts under the master cylinder, suspended off the left/outside bolt on the master cylinder. (Your 68 hold off bolts under the master by the right/inside m/c bolt). Actually the very easiest way to do the changeover on the 66 cars would be to use the stuff for the 71 up which is supplied with the changeover kits. You just use the supplied prop valve and bracket, so when bolted up top, under the m/c, you have the valve and distribution block. So all you would HAVE to do is remove the 66 distribution block, run 3 short lines from the prop valve which is up top to the 3 lines, two front and one rear lines, you removed from the 66 distribution block. You can join them with a brass coupler which is made for that very purpose, it is about 1" long with a place to screw the lines into each end. The two lines for the front are 3/16, and the one for the rear is 1/4. I bought all this stuff and was going to do just what I described to you. But the 66 Cutlass has the starter and battery on the driver side as opposed to your Buick which is on the passenger side. And the Cutlass has a battery junction block/horn relay on the inner fender right where the bracket and prop valve supplied in the kit hang. It wouldn't work for me on the Cutlass. Those are the parts I have left from mine that I could sell. I have a new master cylinder, prop valve and bracket, all the lines and brass couplings. Mike
Another option: - Leave the '66 distribution block on the frame, with the two front lines attached. - Remove the rear line from the dist block, and install a plug in the block. - Run one new line from the hold-off valve on the 68 setup to the port on the 66 distribution block, for the front brakes. - Run a second new line from the master cylinder (for the rear brakes)to the '66's rear brake line. The 66 rear line is a 3/16", not sure what the master cylinder line from the '68 is... it may be a 1/4", so you may need either a connector for 1/4" to 3/16", or cut/reflare the old '66's 3/16" brake line and install a nut with the larger 1/4" line nut on it. - You will need to use the '68 spindles. Ball joints between the 66 and 68 are the same, but you might as well install new ball joints. Mike, do you recall if the 68-72 steering arms (that bolt to the spindle) are longer than the 64-67? The later ones do use larger diameter bolts....
Hey Walt, your senario sounds better than mine, should work fine. Wish I had done this to mine now. But too late to go back. The line going to the rear on my 66 Cutlass is a 1/4, but I checked on a 66 Buick rubber rear brake hose and it does indeed look like the Buick line going to the rear is a 3/16. You can tell by the thread size, normally, a 3/16 line has a nut with 3/8x24 thread and a 1/4 inch line has a nut with 7/16x24 thread. On the steering arms I am not sure, But I would bet they are exactly the same. It would be very easy to check with a tape measure. I didn't remove mine from the tie rod, I just left the tie rod attached, removed the 2 bolts holding the arm and backing plate. I took mine off in pieces to make it lighter, more pieces to handle but easier on my back. I also took my lower control arms off and put new lower ball joints as mine had some wear, uppers were great. Another slight difference I see between the Cutlass and the Buick 66s. The rear rubber hose on the Buick fits into a junction block at the differential housing judging from the way the line looks,,, and the Cutlass rear rubber brake hose has the junction block made into it. Funny little differences. Which also makes me think the 68 Cutlass stuff he has to use would have a 1/4 inch line going to the rear, so that makes your idea even better with less changing. Another thing, the Carquest Auto Parts in my town is an old, old business with equally old personnel. I go there a lot. They carry fittings in brass & steel which they call master cylinder adapters. These can be used to adapt one line size to another. Meaning you can screw the adapter into a master cylinder that has 7/16x24 threads which you would associate with a 1/4" line, and then screw a 3/8x24 thread into it, which you would associate with a 3/16" line. So he could avoid having to cut and re-flare his lines. These adapters come in many different configurations to adapt most any line size. Speaking of this re-flaring stuff. I will give another little fact I recently heard. The lines you buy at the auto parts which are already flared and have the nuts installed are not intended to be re-flared. The lines which you buy in a roll are the ones intended to be flared at home, they are softer and are made by a different process than the more rigid pre-flared ones. This suprised me as I have re-flared a lot of them. Thanks Walt, you're the best, I really appreciate your expertise, Mike
Thanks to both of you, this really helps. Walt, we "spoke" before when the new brake lines coming with my Skylark wouldn't fit my car. I had the new 1/4 line from front to back and it didn't fit as the old line was 3/16. As I had to bent a new 3/16 line, I have no problem with bending another one or using the stainless that came with my brake line kit. It would be fine if I could use my Lemans brakes for the Skylark.
the 64-72 drum spindels are the same as disc gm just machined down the little bolt area from the factory. alot of guys do it to there drum spindels save from buying new spindels when doing a disc swap.
Somebody may have mentioned this but doesn't the 68/72 swap onto a 64/67 move the front wheels out about 1/4" to 1/2"?
