I've removed the master cylinder from my '67 RS/SS. The car has power brakes - discs in front, drums at rear.

The (primary?) piston popped right out after I removed the snap ring. The other (secondary?) piston, however is a different story. I don't have an air compressor, and it's in too far for me to get out with needle-nose pliers.

I've read that you can pull it out somehow using a wire, but can't find an explanation that works for me.

Can anyone tell me a trick to get that thing outta' there?

Thank you!

Can you use an external retainer ring pliers?

Have a Mity-Vac? Use the exhaust side as the compressor. This would be the top nipple with the removable cover on it.

Or slam it hard onto a block of wood, mounting flange down.

I assume you already removed the retaining bolt in the front resivoir if it has one.

I'd take it to someone with an air compressor if Everett's advice doesn't pan out, or, one other thing to try is pushing it in against its spring, bottoming it out, and releasing quickly. Do this a bunch of times and it might eventually pop over the varnish ring, then tap it down on the wood, flange down.

If you end up using compressed air, be prepared... that thing can shoot out pretty hard and/or far ;)

I exhausted all of what seemed to be intuitive methods (slamming it down on a block of wood, jamming the piston all the way in and hoping it would pop out, fishing around with a wire, prayer...) to no avail.

So - yesterday, the nice folks at a nearby Wal-Mart Auto Center let me use their compressor. You ain't kiddin'! That little thing shot out like 6 feet!

Now I can clean it out and rebuild (assuming the kit I bought is the right one). Most of the paint on the master cylinder and some on the power booster got eaten away due to the leak. I suppose now would be a good time to repaint them. Is there any special paint I should use?

Thank you!

The booster once was plated. You can have it replated, use whatever paint you use in the engine compartment, or there are some paints which mimic the plating. I found some info on that in a search once here.

I don't know of any paint which holds up to brake fluid for long. I coat my master with wd40 once in a while... just dont get any in with the fluid.
Someone else may be more help there. My painting skills are marginal at best.

I popped the secondary out of a drum cylinder recently at about 150+psi, pointing it into the backyard just to have fun.
It shot about 20ft ;)
Normally I would block it with some wood. That piston should probably be replaced.

Do you think I should replace both pistons? Where can one obtain said piston(s)?

The primary should come with a rebuild kit.
The secondary...
It depends on the cylinder.
The aftermarket rectanglular master kits sometimes come with the secondary.

If it's the OE oval disc/drum cylinder, the only two sources I know of to get a secondary piston is 1) from a cheap rebuilt master, or 2) from http://www.corvettepartsman.com/
either way, you might have to also get a rebuild kit from the parts store if you want a new residual valve for the rear drums.

If someone else knows a source for secondary pistons, or a kit with them, I want to know.

So I got the MC all cleaned out, put new rubber bits on the secondary cylinder and put in the new primary cylinder. Got it all put back together and on the car, and... still f*&^ing leaking!!!

I can see 2 places where it's leaking. One is where the MC meets the power booster. I'm wondering if there's a worn out piece of rubber there, or if something is missing. My rebuild kit for the MC had a big rubber part that looked kind of like a boot, but there wasn't anything like that on the MC when I took it off. I'll bet that was supposed to go between the power booster and the back of the MC, huh?

The other thing that's leaking, and leaking badly, is the proportioning valve. It seems like it might be leaking at the back, where the rubber boot is. Do those go bad?

As luck would have it, this tiny, leaky part seems to be rather pricey! Do they make rebuild kits for those, or am I just going to have to buy a new one?

The boot is for manual brake cylinders.

Most rebuild kits should come with all new seals, PLUS the primary piston WITH the new seals already on it.

Many RMFG cylinders will replace the very rear seal with an Oring, as this is where the most cylinder wear often occurs. It's also not primarily a pressure seal. If the rear seal is bad, or there is excessive wear, the cylinder will leak out the back even if it holds pressure.

If the cylinder is smooth, with no pits, and was cleaned with emory cloth or a VERY LIGHT hone, it should be fine with all new seals.

For the disc brake valve off the front resivoir line (I guess this front brake only valve is the one you mean), I have seen some rebuild kits for slightly less than a new one. Check Ebay, sold from heartbeatcity.
If you take it apart and clean the stem, it might stop leaking, but the seal could have hardened.

Would a leaking proportioning valve cause the brake system not to build pressure? I'm able to push the brake pedal to the floor with the cap on or off the MC.

With as much stuff under my hood that's not original, I'm debating on whether or not I should just get a remanufactured MC. If I did that, could I use some cheaper, more readily available proportioning valve?

I have stored all the original stuff I've replaced, but hell - at this point, I want stuff that works so I can drive the car!

A leaking valve could cause that. Often the small one next to the master will leak air in.
Any fluid leak can cause a sinking pedal.
Determining exactly what the cause of the problem is BEFORE buying new parts is always a good idea.
http://www.winbrake.com/trainingmaterials/LowPedalDiagnosis.html
(PDF Download Troubleshooting chart) http://www.ucx.com/documents/softpedal.pdf

You can get a new master and still use the stock valving.
You can replace the stock valving with a more modern combo valve, but you'll have to so some line work.

I took the prop. valve off today and cleaned up everything inside. I put it back on the car and so far, nothing is leaking.

However, I'm not getting brake pressure. The pedal goes down with a little resistance and pops right back up, but it never seems to build up pressure.

I probably messed things up by not bench bleeding the MC before I put it back on.

Do I need to go through and bleed each wheel before I can expect to see good pressure, since I probably introduced a bunch of air with a dry MC?

You can bleed the master on the car, as per service manual. If it's equipped with bleeders, use them, if not, bleed from the ports by opening the line slightly and push on the pedal. repeat for both lines a few times... basically the same as bench bleeding, but on the car, even if it is at an upward angle for power brakes. be wary of brake fluid.

Yes, you'll have to bleed the wheels. There is a pocket of air in there from when you had the valve off.