bleeding brakes

[OGcutdawg_83]

hello,
Ending my project ls swap 83 cutlass. In the build I did the rear disc brake conversion, and the disc to disc proportion valve, new master cylinder w/ reservoir , and new brake lines.

I'm by myself majority of the time so I purchased the harbor fright vacuum bleeding. The bleeding went successful UNTIL I started the car. My brake pedal goes all the way to the floor and I have no brakes. No leaks that I can see. So I re-bleed the brakes. With the car off brake pedal seems normal again until I start the car. I've since purchase a new booster valve. Also I hear a lot of air when pressing the brake pedal. I'll try the old school conventional way of bleeding (2 man) when I can get a buddy to help.

Any help is welcome. Also check out my YouTube channel.

 

[Streetbu]

Bench bleed the master cylinder first. Then move on to each bleeder valve.

 

[Bonnewagon]

Bench bleed the master cylinder first

Absolutely!
I don't like vacuum bleeding. Even gravity bleeding is better. But the best way by far is the two-man team pumping and bleeding. You can build pressure that blows out air and debris so much better. If the pedal is hard with the engine off, then goes to the floor when it is on, yes, the booster is leaking. The whooshing sound is a clue. But there is a felt gasket down there that is supposed to quiet that so see if it is still there.

 

[Longroof79]

I've been pretty successful using speed bleeders and sometimes submerging a piece of hose in a clear jar with some brake fluid in it.
I find the rear bleeders a hassle due to not allowing enough space around the bleeder to use a wrench and small piece of hose.
I never pressure bled the system, but always wanted to make my own pressure bleeder using a small pump sprayer and making an adaptor plate for the top of the master cylinder reservoir.

 

[Bonnewagon]

We used to have a pressure bleeder. They work great but they are really for a shop that does brakes every day. You fill the tank with brake fluid and there is a bladder that you pump up with air to pressurize the fluid side. The problem is that the brake fluid is hygroscopic [absorbs moisture] and any spill left on the tool makes it rust like crazy. Under the bladder was the worst as brake fluid got under there and rusted the insides of the tank. A shop can afford to repair/replace the tool but a DIYer would be hard pressed to use the tool enough to justify the cost. I do see some now made of plastic which would not rust and they are much cheaper then what we had.

 

[Longroof79]

We used to have a pressure bleeder. They work great but they are really for a shop that does brakes every day. You fill the tank with brake fluid and there is a bladder that you pump up with air to pressurize the fluid side. The problem is that the brake fluid is hygroscopic [absorbs moisture] and any spill left on the tool makes it rust like crazy. Under the bladder was the worst as brake fluid got under there and rusted the insides of the tank. A shop can afford to repair/replace the tool but a DIYer would be hard pressed to use the tool enough to justify the cost. I do see some now made of plastic which would not rust and they are much cheaper then what we had.

Mark,
You're right about the corrosive properties of brake fluid, plus the fact that brake fluid is hygroscopic. As for the pressure bleeder. I was going to originally make one out of a length of PVC pipe. A friend of mine made one like that years back. The downside is that you need compressed air to make it function. But I still like the simple idea of using a small garden sprayer. They're certainly cheap enough to obtain. Although you'd still have to make a few modifications to it....no biggie.
I was wondering about altering access to the rear bleeders. A taller bleeder would be helpful, if there is such an animal, or opening up the access hole, which would require removing the brake cylinder(s) temporarily and boring out the hole grinding stone.

 

[Bonnewagon]

Jack I gave up and now I just have someone help me bleed them. What I don't understand is getting "helpers" to know what I mean when I say "UP" or "DOWN" commands. It ain't rocket science! I found that by using those little rubber bleeder covers they stay clean and don't rust. I even spray some WD-40 in the bleeder then snap the covers on. If you go to a parts store look for the "HELP" section. Dorman makes some tall bleeders that are much easier to get at. Just match up the diameter and threads to ours which are pretty common.

 

[Longroof79]

Jack I gave up and now I just have someone help me bleed them. What I don't understand is getting "helpers" to know what I mean when I say "UP" or "DOWN" commands. It ain't rocket science! I found that by using those little rubber bleeder covers they stay clean and don't rust. I even spray some WD-40 in the bleeder then snap the covers on. If you go to a parts store look for the "HELP" section. Dorman makes some tall bleeders that are much easier to get at. Just match up the diameter and threads to ours which are pretty common. View attachment 209775 View attachment 209776

Mark,
Thank you for the great advice. On my old Porsche. The bleeders have little caps on them, which I always thought was a great idea. I will pick up some the next time I'm at the auto parts store...and also look into the longer/ taller bleeder valves.

 

[Bonnewagon]

Hey Jack I learned about those little covers working on a VW. Them Germans be pretty schmart,eh?

 

[Longroof79]

Hey Jack I learned about those little covers working on a VW. Them Germans be pretty schmart,eh?

Ya vol, they are pretty schmart. Come to think of it, I did see them on other German cars.