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Discussion Starter · #1 ·
(Our obviously rusty 96 RMW has recently sprung a rust leak on the brake line halfway to the rear. It made me realize just how I badly I screwed up by not flushing the fluid out the rear brakes in years. And then it occurred to me that our new other 96 RMW (with the bondoed-over rust, the painted-over rust, and the latent deferred-maitenance problem du jour) is likely even more neglected in this regard, and with hydrophile DOT-3 to boot. So I'd like to flush the rear brakes in a hurry.)

Does anybody know of or have (or not mind typing up) B-body (or resonably close generic) drum brake service instructions? I can't seem to find anything.

I'm reasonably good at replacing pads etc. on disk brakes, but at the rear drums, I don't even know how to open it up once the wheel is off.

I'm figuring that once I know what to do, it can't possibly be as inconvenient as the logistics of taking it to a mechanic, convincing them to use (my) better fluid, and dreading them screwing it up or price-gouging me (or both), as has been universally the case in this town since we've moved here.
 

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Your almost certainly going to have to replace the wheel cylinders in order to bleed them.

The bleeders are on the back of the drum at the top. Unfortunately those dang bleeders on the wheel cylinders love to break.

If your replacing the wheel cylinders, you might as well replace shoes & hardware/springs as well.

A $20 Haynes manual has a picture of the hardware/spring setup - and instructions for the job. That's the only somewhat difficult part of the job; setting up the hardware & springs.
 

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It's the same as calipers, but the bleeder is in the back and towards the top. Here's the key...PB blast and loosen the bleeder screws prior to applying brake pedal pressure. More wheel cylinder bleeders snap at the base from this than any other reason.
 

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Discussion Starter · #4 ·
If I end up having to replace the wheel cylinders, are the brake line connections likely to be as much of a rust problem as the bleeder screws?
If the bleeder screws end up being so recalcitrant that I try and succeed to disconnect the brake lines from the cylinder /before/ breaking off the bleeder, are the wheel cylinders reasonably available and inexpensive from a store like AZ? Or is this one of those deals where I better line up all the parts before I risk breaking something?
 

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If I end up having to replace the wheel cylinders, are the brake line connections likely to be as much of a rust problem as the bleeder screws?
Yes. Hit them with penetrant before you start.

If the bleeder screws end up being so recalcitrant that I try and succeed to disconnect the brake lines from the cylinder /before/ breaking off the bleeder, are the wheel cylinders reasonably available and inexpensive from a store like AZ?
Yes.
 

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Pb blast them and try loosening them. If they loosen, you're good to go. If they snap or strip, they won't (shouldn't anyway) leak, so you can get a wheel cylinder (and probably shoes while you're in there since you'll will have to at least dislodge them to get to the wheel cylinder) then.
 

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Oh, one more tip: Always use flare nut wrenches on the nut holding the line into the wheel cylinder. They're your best bet to keep from rounding it. If you do round the bolt, its time to break out the vice grips.
 

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Discussion Starter · #8 ·
Pb blast them and try loosening them. If they loosen, you're good to go. If they snap or strip, they won't (shouldn't anyway) leak,
That's good to know, thank you. That means I can start without further preparation (e.g. soak with PB B. tonight, start to try to get them off tomorrow morning).

I wonder whether I'm better off with the wheel off (room to move, easier to reach) or resting on the tire (more stability for leaning hard on a wrench).
 

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Discussion Starter · #9 ·
Oh, one more tip: Always use flare nut wrenches on the nut holding the line into the wheel cylinder. They're your best bet to keep from rounding it. If you do round the bolt, its time to break out the vice grips.

Good point. I guess I also need to make sure I have a deep anough socket to really grip the bleeder screw.
Questions:

-what are the size of the bleeder screw and the line bolt?

-which way is the bleeder screw pointed? up, down, parallel with the rear axle, or some angle?
 

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I learned something about drum brakes this weekend. If the brake drum doesn't go back onto the new brake shoes, you might have installed both large brake shoes on the same wheel. :|

The large shoes are supposed to go in back of each wheel.

I tried to use a tubing wrench on the bleeder valve, but I didn't have one the right size. My 1994 RMW was 5/16". A six-sided box wrench worked as well. It's at the top of the backing plate, pointing straight inboard. I had to sit inside the fender to get it loose.
 

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New cylinders are about $10 each. You need some special tools to remove the shoes. Check your local parts store. The cost of the tools, and parts is about the same as a brake job. If you buy them, you will have them for the next job. The brake shoes are front and rear...small to the front of the car. Get the book.
 

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Everybody, go out now and spray penetrating oil on your rear brake bleeder screws and brake line fittings. And then do it again every two months, because at some point down the road you are going to have to do this yourself, so let that oil soak in for a loooooooong time.
 
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