Projects Cutting my Hotrod Teeth (57 Chevy Budget build/revival)

good to see you back at it...what master cylinder did you use? I used a '68 Malibu drum/drum master, 1 new line across the firewall to the rear line, and a plug to separate the front system and didn't need a proportioning valve...(by the way I got my old '57 running then sold it shortly thereafter...then bought 2 more) so I'm starting from scratch...seems like the '68 'bu master isnt as easy to find as 10 years ago

 

Also how I did mine and works excellent with the original drums. If you're not converting to disks the prop. valve is unnecessary.

 

Sorry for disappearing again, life has been very busy since I last posted. My fiancee and I bought a house, and I got the car moved into my new garage!

I’ve been picking away at it over the past couple weeks, just doing jobs that I already have parts lying around for. I had a basically complete brake system, so I decided to bite the bullet and do the job I was most dreading… completely replacing the extremely rusty brake lines, and rebuilding everything at the wheels. There was unfortunately just nothing worth saving, so it was a total gut-job.

The shoes/wheel cylinders were all pretty easy, thanks to the brake kit I was so generously given by another member years ago from this very thread! Only one little hiccup was that I had to hunt down some wheel cylinder pins, because some of mine were pretty badly bent.

Over this past weekend, I tackled the plumbing. I ripped out all the old hard lines (Hoses were already replaced when I did the shoes) and replaced them with the pre-bent kit I bought half a decade ago.

Now here come’s the issue I’m facing now…

I didn’t bleed the master out of the car, but when I added the fluid, I had the brake pedal held to the floor, and loosened the nuts on both ports, until they were dripping fluid, so in my mind, that should be as good as a bench bleed, right?

Next, I pumped up the brakes until I could see the fluid splash out of the master. I replaced the cap, and held the brake pedal down with a 2x4. I went to the RR wheel, and opened the bleeder. I did hear a hiss of air, but no fluid came out. So I went to the fronts to see if I had any fluid there. I did get a little fluid from the front bleeders, so I went back to pumping the pedal to hopefully push the fluid back to the rears. I probably pumped the pedal for 10 minutes, and then had my fiancee operate the pedal as I checked the rear bleeders again. A got the smallest amount of fluid out of the RR bleeder when I loosened it, but then nothing when I had her hold the pedal down again.

At this point I noticed several leaks at the various fittings in the engine bay, which I fixed. That was last night.

This morning, topped off the fluid and again held down the pedal with a 2x4. I got absolutely NOTHING from the RR bleeder this time. Not even a hiss of air. I double checked for leaks and found none. I opened the master cylinder ports again and they both dripped fluid.

But man an I stumped. All of the lines are brand new. There should not be any clogs. Now, before I go around to each fitting and bleed the system out one by one, id there anything else I could try?

Am I missing something? Do I need to have the brake shoes tightened up? Do I need to connect a hose fed/submerged into fluid to the bleeders when I open them instead of just cracking them to open air? I’ve read up on brakes quite a bit before doing all this, but experience is king here!

 

Hmm, that’s one thing I have found conflicting info on, and am not really sure which way to go. The kit I bought from Ecklers or Danchuck was for a drum/drum setup, and I’m keeping drums for now. The instructions say that you have to use the valve when going to a dual master, even with only drums. You’re saying I can/should remove it? I’m trying to keep it as simple as possible, and that valve can go if I really don’t need it!

 

Yes, you do not need a proportioning valve with 4 wheel drums and a master cylinder for 4 wheel drums. I don't have one, I've put 20,000 miles on that setup in the last 6 years and it works great, I can't figure out what the purpose of it would be on an all drum car. Although I did not buy any "kit", just an off the shelf '68 Malibu master and one extra brake line to convert it. I'd like to see what actually came in the kit you bought.

I will say, once this system is dialed in and properly adjusted, those manual drums have great stopping power. You need a bit more foot pressure than a modern system, but you can lock up all 4 wheels pretty easy and send a p***enger into the windshield if you really want to.

As for the master, you absolutely need to bench bleed it. I personally would take yours back off and bench bleed it, those little bleeder kits are cheap and very handy, I use one. Clamp it in a vice and pump it with an extra brake rod if you have one, or an old pushrod or a rounded off screwdriver works nice too. After the first few pumps you'll probably only get one little tiny bubble out at a time, but keep doing that until there's no bubbles for several pumps.

I guarantee the pressure issues you're having is that you're compressing air at the master so the pressure is not making it to the wheels.

 

Congrats on the house! Garage is a plus.

 

Well, sounds like the master is coming back out to be bench bled then! I think I’ll ditch the prop. Valve at least for now too. One less thing to cause issues, and if I do end up having issues actually braking, I can always try adding it back in.

So, my method/idea of just bleeding the master by opening the ports with the pedal pushed in doesn’t work? I guess i’m just struggling to see a difference in the method. Either push the plunger in with a screwdriver or the pedal, should be the same outcome?

 

If you just open up the ports, fluid will come out, but you won't force the air out of the plunger. It takes a lot of pumps on the bench to get every bit of air out, and also the pushrod in the car isn't necessarily bottoming out every time. It's not the p***age from the bowl to the line ports you're bleeding, it's the plunger to the bowl, there's air trapped in there that won't come out just by opening up the line ports.

 

That makes more sense, thank you for the explanation! I’ll grab a bleeder kit after work and give it a go.

 

you'll be surprised how effective putting a long piece of plastic pibe screwed into the master and the bleeder screws open can work-a few pumps on the pedal,and some brake fluid on the ground or rags...