Hey - part II (you knew it was comin'!) of my quest to upgrade my incoming project, A '72 Skylark rag with manual drum brakes that I want to swap for front discs. I know I'd need the spindles, backing plates, etc, but what about brake lines and prop valve? Since the pdb master is pushed farther out by the booster, would the original drum hard lines reach and bolt up? I presume the pedal assembly differs between manual and disc cars as well. Is there a brake guru out here who can outline the items I need to complete this swap (or advise of any luck they've had with aftermarket complete swap kits)? Many thanks!
Hey Geek! I changed to disk brakes on my 67 about two years ago. From my experience, it may, MAY, be easier, take less time and close to the same money to go with one of the aftermarket kits. My car already had power drum brakes so I'm sure my set up varied from yours. There are a couple of things you'll want to pay attention to. First, unless you have access to the actual car the stuff is coming off of to swap to yours, try to be there when it comes apart. My stuff came from a 70 Monte Carlo (yep, they are A bodies). The pedals are the same, the difference is the hole in the arm that the rod goes through. Power brake cars probably also have longer rods since the extra 6-8 inches for the power booster needs to be covered. Shouldn't be a big deal to take off your old master cylinder and slide the new unit in it's place. If the master cylinder and booster aren't already assembled, do yourself a HUGE favor and put them together on a work bench, then put the whole assembly in the car at once. You will absolutely need the proportioning valve from the donor. Don't expect the brake lines to bolt right to the new one though. Fortunately for me, the replacement one I got simply had the brake lines cut and the fittings left in. I re-used the fittings by cutting just enough of my brake line to get the old fitting off, put the new fitting on the line and created new DOUBLE FLARES! Remember, for your safety, the safety of any passengers and everyone around you when you are driving, double flares are mandatory for brake lines! :Smarty: The soft brake lines will need to be replaced with ones designed for disk brakes. Your stockers will be set up for bolting into wheel cylinders and won't fit the caliper connection. My stock brake lines bolted right to the new master cylinder. No mods needed there, but then my car was power drum. The other thing to remember is bleed, bleed, bleed then bleed some more. Use good brake fluid and be sure to get all of the old stuff out by bleeding. Over time, brake fluid absorbs water and heat can break it down, particularly over the number of years it has probably been in there. If you can take apart the front-end and get the old spindles off, you may want to replace the ball joints at minimum. Don't know how many miles are on your new ride but remember, if those joints are factory, they are something like 33 years old! You're into it that far, you may as well do those too. Though I haven't driven my car with the new disks, I had a 71 Chevelle with manual drums. Scary stuff. My 70 GS could stop in about 1/2 the distance. Factory disk/drum set up. If you have any questions during the swap, just ask. :bglasses:
I'll second that. Check your control arm bushings while you are under there too. Mine were trying to push through the lower control arms (arm metal was cracking) - had to replace the arms. I used junkyard parts, and the junkyards knew what would fit. You'll need a booster, spindles/knuckle, and the proportioning valve. Get new calipers, soft lines, and master cylinder. Might as well make sure the hard-lines are in good shape while your at it. This would be a good time to replace them. Oh, some of the kits will give you a better steering geometry - better handling. Whatever route you choose, you will love the power discs.
If you go that far consider pricing wheel bearings too. It's not a real complicated procedure on your car. Hey Truzi....cool vw avatar! Herbie? it's nice to see I'm not the only one without digital pics of my Buick. Tom
