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Brake rebuilding time. Lots o' questions!


FastWoman

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Thanks to Rob's generosity, I'll be going stock with the rears! Thanks, Rob! :)

Zed, thanks for the heads-up about the fit of the shoes! I remember drums as being a bit of an excercise in frustration. Yeah, removing them is usually a bear, and y'all are starting to scare me about the hydraulic fittings! ;)

Thanks for explaining about the braided lines. I'll be sure to remove Earl's cautionary tag.

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Yup it was me who had weak back brakes on the 77 ZAP I just worked on. It took a while to get the new brake shoes to finally take a "bite" in the drums. In retrospect, I should have used a lower grit emery paper to surface the drums. I think I used 400 or 600 grit. The FSM calls for the right way to prep the drums. The performance shoes from MSA that I used, are already beveled on the leading and trailing ends.

+1 on the MSA braided brake hoses.

Edited by cygnusx1
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Dave, I remember seeing a pair of Mountain Rotor rotors that were rough beyond belief. The mechanic said they were supposed to be installed that way. They broke in just great. I figure the surface can't be too rough. I usually roughen my rotors (and drums -- which I don't often work on) with nasty, 60 grit sandpaper. I usually get good bite right away, and I've never had squeal problems this way.

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Hi all,

<multiple edits within, I cut out what I couldn't even attempt to answer, many of which I'm interested in finding out>

I haven't done a lick of work to the brakes in the time I've owned the car. Now seems like the time to go through it from front to back, refreshing/refurbing/replacing everything. However, this is my DD, so before I launch into this project, I want to have all supplies on hand. (I do have another car to go to the parts store if necessary.) Can y'all help me refine my shopping list?

I don't need new front rotors or brake pads. Those are fine. I don't know the condition of the rear drums and shoes. What would I expect from a 160k Z? Should I order new shoes, or should I just wait and see?

I'm guessing I need to either rebuild or replace my rear brake cylinders and my front calipers. In my experience, auto parts store rebuilt brake parts are universally crappy, and it's my preference not to trust my life to them. However, I see that MSA sells remanufactured calipers. How are they? As I recall, the pistons are iridium plated and the plating can often be violated as rust sets in underneath. Are the pistons in the rebuilt calipers iridium plated?

Are there any good sources on brake caliper and cylinder rebuilding kits?

I know these are a lot of questions. I'd love to hear your suggestions on any of them.

Thanks, y'all!

Peace,

Sarah

FastWoman,

The beginning of a great adventure.;)

Perhaps a bit impudent, but why are you so sure your rotors and pads are in good condition? And if you are sure, why do you want to replace the calipers? If they are working and not leaking, they are working and not leaking, can't ask for more than that. And, at least on my 1072, the calipers are a fairly easy job. Easier than replacing the pads, IMO, though, obviously the former can't be done without also doing the latter.

Of course you should order new brake shoes and probably rebuild or replace ($$) the wheel cylinders. I mean, if you agree with my reasoning above and don't get new shoes and cylinders, you would hardly be doing a brake job, no? ;)

Straight up, yes, definitely should get new shoes.

If the 1978s are like the 1972s, and I believe they are close enough, inspecting the rear brake assembly, once you have gotten the (bad word) drums off the first time, is easy enough and non-destructive. So, it isn't really necessary to order every possible replaceable part in advance. If the wheel cylinders are working OK and not leaking, I'd try to find a rebuild kit. Let me know if you find a source, as I've got to do the drums soon myself. Pull the brake drums and if you have a micrometer that measures inside distances, take a few measures and if none are under, I think it is the minimum spec. plus .04 inches, you should be able to get them turned. Or if you don't have a micrometer, pull the drums and do the Southern Woman eye-batting thing until a gentleman at a brake repair shop offers to measure them for you in honor of the glory of Southern Womanhood. (I get this feeling that you would like Florence King.)

So here, I'd rebuild the wheel cylinder if a kit can be found. If not, boy, they are expensive little devils. I guess if they look at you cross-eyed in the least, I'd bite the bullet and get a new pair. Get Zen on the Drums. You either will need new ones or you won't -- it's out of your control now.

Here's a recent thread on relined aluminum drums. There were one or two other sources "on their way" mentioned as well, but this one appears ready to go.

http://www.classiczcars.com/forums/showthread.php?37396-Anyone-interested-in-relined-Aluminum-drums&highlight=drums

And peering into the future:

I asked a similar question about rear disc conversion a couple of months ago. No one said it was worthwhile if I'm not racing. Heck, at least one racer said he doesn't think they are worth the money for racing. Though I'm guessing it depends on the type of racing.

Chris

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Oh, and I forgot to add:

Nothing wrong with putting the penetrant on a day or two days early. Put some on, give it a few raps with a hammer. Give it another couple raps every time you walk past the car and top off, so to speak, the penetrant if its looking a bit dry.

Chris

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Anyone use MSA's stainless braided hoses? How are they?

http://www.thezstore.com/page/TZS/PROD/PBC08/24-5121

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Are these MSA 4-piston caliper kits worth considering?

http://www.thezstore.com/page/TZS/CTGY/PBC07

What sort of car do they come from?

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And has anyone used MSA's rear disc conversion kit? Is it worth the money to do this if you're not racing?

http://www.thezstore.com/page/TZS/PROD/PBC12/24-5583

www.silverminemotors.com offers a more complete kit for less $$. I have their stage 4 front & rear and it was worth it. The fronts are from a Toyota 4runner & the rear are a Mustang GT 500

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Don't know about VA, but the stainless braided hoses "should" not pass the annual state safety inspection in Pennsylvania. I say "should", because lots of people have those hoses on their cars and pass inspection anyway. Not supposed to, but...

Rebuilding the 77-78 rear cylinders is mind-numbingly easy. Only thing that can go wrong is if the cylinder body is corroded where the piston seal contacts it. If that's the case, the cylinders are toast.

Also, since this is a DD, getting the drums off shouldn't be a chore either. Assuming the adjuster mechanism isn't frozen solid, you should be able to pull the access nubbin and adjust the shoes back far enough that the drums will almost fall off. Easy for me to say this sitting from my chair, huh?:laugh:

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I've had decent luck by putting vice grips over the flare wrench -- keeps the flare wrench from spreading and doesn't tear up the nut on the brake line. Squirt them down with PB-Blaster or the home-brew 50-50 acetone & Automatic Transmission Fluid first.

A few choice words later, and you should be good to go. ;)

These vise grips have worked very well for me.

post-15138-14150816400793_thumb.jpg

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Thanks for the advice, guys!

Jetaway, I guess you missed that Robftw offered up a new pair of cylinders and set of shoes for my Z. :D So that takes care of most of the rear end. I'm hoping/assuming the drums aren't too worn to be turned. I'm afraid I'm no longer young/cute enough to pull off the eye batting thing, but Southern gentility is often afforded to sturdy, older gals such as myself, too. ;)

I've had the wheels off recently and know that I have most of the pad thickness on both sides. I'm assuming rotor thickness is fine too. I have no idea about drums. I see this as mostly a hydraulics job, but the drums can probably stand a refresh too. (I see no mention of drum work in the service records that were passed along to me.)

30ounce, would the 4-piston kit be compatible with rear drum brakes and the OEM master and proportioning valve?

http://www.silverminemotors.com/Front-Big-Brake-Kit-stage-3-Front-Big-Brake-Kit-stage-3.htm

That's a nice price, and I wouldn't mind a bit more braking oomph.

And Captain Obvious, their steel braided brake lines are DOT approved! Woohoo! :D

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Thanks for the advice, guys!

30ounce, would the 4-piston kit be compatible with rear drum brakes and the OEM master and proportioning valve?

http://www.silverminemotors.com/Front-Big-Brake-Kit-stage-3-Front-Big-Brake-Kit-stage-3.htm

That's a nice price, and I wouldn't mind a bit more braking oomph.

The stage 3 kit and stock rear brakes will work fine with the stock MC and PP valve. If you go to the stage 4 kit I would recomend the 15/16 MC as the pedal travel gets e little long. You'll get more braking power and the pedal feel & modulation are greatly improved. Probably one of the best improvements I've done to my Z.

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