The three different bore sizes are probably for either a 6 cylinder with 9" drums, a small block v8 with 10" drums, or a big block car that also had 10" drums but came with bigger brakes.

When you take the brake cylinder off, pop off the dust boot from one side and push in on the other side to push the piston out of the side with the dust boot off. The back (flat) side of the piston will have the piston bore stamped in it. Should be something like 11/16 or 7/8, don't recall off-hand.

Your brake cylinder is $10.99 per side at Autozone with a 3 month warranty. I don't think they do lifetime warranties on brake cylinders anymore, but that might be the $50 one if it is available.

Like Scott was saying, better get on this quick, as the brake fluid will cause your brake pads to disintegrate, any piece that got wet if allowed to soak through will literally crumble apart.

If you have never flushed the system, now would be a good time to do so since you are installing some new parts. A 1 quart bottle of DOT 3 fluid will be fine to flush and fill it the system. Autzone sells a handy one-man kit for bleeding, works great for like 5 bucks. I know I'm throwing out $3 here and $5 there and it adds up, so if need be get a buddy or the wife to help and save the 5 bucks for parts.

Rather than type it all out, I cheated with google...
http://www.stoptech.com/whitepapers/howtobleedbrakesright.htm

Skip down about 3/4 of the way to Bleeding Process if you've never done this.

The bleeding process is explained in the link above. If your brake system hasn't been flushed in a long time, you probably have water and rust particles floating around which will ruin your new brake cylinders. Follow the instructions for bleeding at the passenger rear corner and continue bleeding the brakes until you get nice clean clear fluid out with no bubbles. Be sure to top off the master cylinder several times while doing this to keep it from going dry. Repeat at your driver rear, and then go ahead and go to passenger front and driver front. Once all four corners have clean fluid coming out, no bubbles, top off the master cylinder and continue with the instructions as above.

BTW, front compartment of the master cylinder goes to the rear brakes and vice versa.

I forgot to tell you, as soon as you start bleeding the brakes and if you get nasty looking fluid coming out, it will be obvious if you need to just bleed them or do a flush.

While you have the brakes apart, remove the 4 nuts that hold the backing plate bolts. You get to the nuts through the hole in the axle plate the wheel studs are mounted on. Just spin it around until the hole lines up on each nut...

After you have all four bolts out, you can try hammering a 5/16 rod through the backing plate bolt holes against the axle and also putting the drum on backwards and 1, having it tight and beating on it with a hammer or 2, having it loose and using it as a slide hammer. I've seen some other recommendations on here but don't recall what they are off-hand.

Once you break the bearing loose the axle will slide right out, and then the bearing is there to be removed. I think you can rent a seal remover from Autozone, or buy one if you don't have one, they aren't too expensive. A screwdriver and hammer also work but require more time and profanities.

As for the wheel bearings, you have to have a machine shop change them for you, so besides the cost of new bearings, you're looking at $10-20 a side to have them changed.

I recognize you're getting into a lot of "well, since I'm here, I might as well do this" and the price of your project is quickly spiralling out of control.

If you have the funds to do wheel bearings now, do it, if not, it can wait. And when the time comes, you'll already know how to take the axles out and it will be a quicker job for you then.

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Bob
Member#39
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