maireeka

I just got my 79 project running and she needs brakes badly. I want to do the front pads/rotors as well as the rear shoes. (no drums because I plan on a disc swap sometime in the not too distant future).

I was reading that one should do the bearings/races/etc when one removes the rotors. Is this really necessary? It seems like if you repack the bearings they should last longer than the car does. I know I have never had one go out, and I've driven a ton of high mileage, crappy, old cars.

I'm trying to do this on the cheap, but the rotors are so bad that I will definitely have to replace them.

mazdaverx713b

iTrader: (91)

its not always a must. pull the inner and outer bearings. clean them and check for wear and play. if they're good, re-grease them and replace the grease seal.

djessence

its best to replace the bearings but not absolutely necessary, but think of it as the only means that keeps the car rolling smoothly so its probably a good idea to wait a week or 2 and spend the 150 on bearings

64mgb

iTrader: (1)

I'm almost always in favor of refreshing/restoring/rebuilding whenever possible. It costs you nothing but a little time and a small amount of grease to repack tham. As long as you get them completely clean and dry first, they should last for a very long time.

Rich

Kentetsu

If you are replacing the discs, then do the bearings too. Otherwise, you'll have to drive the races out of the old discs, and insert them into the new discs. Great opportunity to fudge them up in the process. That's what I did this past summer. Parts were dirt cheap at www.rockauto.com I think I paid like 15 bucks each for the rotors and they've held up great...

slimedog

+1, what Kentetsu said.

If new rotors are required (i.e. new hubs) then I'd put new bearings in them rather than put the old ones in, unless the "old" ones were brand new or something.

I used to use up rotors and bearings on a pretty regular schedule when I raced first-gen cars. It's not a big deal to drive the races in/out of the hubs once you've done it a couple times and picked up some tricks, but it could be a little intimidating the first time, and yeah, once oops-scratch on the bearing race and it could self-destruct in a short time.

maireeka

so if i buy a set of bearings, they come with races, and i have to have the races pressed into the new rotors? this is all new to me, i've only ever worked on newer cars that have the bearings separate from the rotors.

ZoomHeart

The bearings will come with races. Seals are separate. As I remember, the existing races are easily removed by pressing them outward from behind the rotor/discs with a large diameter rod/hammer handle/ratchet handle etc.. Pressing the new race on can be done by using the old race as the contacting surface and then again striking with a large diameter rod/hammer handle/ratchet handle etc.. I have had other make cars where this didn't work but it always has for my Mazda's.

A new product(I think it's Freeze Off at Autozone, O'Reilly's, maybe Advanced Auto) can help too. You can spray this aerosol product onto the new race which will make the metal contract and reduce the diameter of the race making the race fit in easier. Perhaps warming the inner new rotor/discs first with a heat gun might make that expand and make the fit easier, too.

Kentetsu

When I did this, I stuck the new races in the freezer for about an hour, then used an appropriately sized socket to press into the new rotors. Pretty easy, just be careful so you don't cause damage to the new parts...

trochoid

iTrader: (6)

The races fit quite tightly in the rotor hubs. I takes a hammer and a drift to tap them out, working around the race to tap it out evenly. I would take the races out of the old rotors and use those to tap in the new ones so as not to damage the thinner edge of the new ones.

Freeze OFF is new to me, didn't know there was such a product. Another option is to leave the new races in the freezer for a couple of hours and heat the rotors in the oven. to around 200*. Insertion needs to be done quickly before the temps equalize. Make sure the races are fully seated and use a press type bearing greaser.

Kentetsu

Trochoid, on my rotors there were two slots cut into it to allow you to drive out the old races. Since I could only drive them out using those two points, I chose not to reuse them due to the possibility of damage or warping. Might be (probably is) different on other years though.

And you reminded me; I did use the old races to drive in the new ones (not a socket). Must be getting old in my old age...

maireeka

guess i'm going to bite the bullet and do everything up front. First i'll do the rear, hopefully the drums don't need replacing but we'll see.

shoes and cylinder rebuilds for sure though.

trochoid

iTrader: (6)

I've reused races often and never had a problem as long as the bearing was good to begin with and I didn't damage the races during the swap.

Kentetsu, I have seen rotors with just 2 slots, races still come out fine as long as they're tapped out evenly.

Kentetsu

I'm sure you're right Trochoid. I'm just paranoid. Besides, the way I see it, if I've got to spend my day working on her instead of driving her, then I'm putting new parts in if at all possible.

I hate working on cars. I really do. So, if I have to do it I want the repair to last as long as freaking possible. Because I really, REALLY, HATE WORKING ON CARS!

But it comes as a side effect of owning them, I guess...