Brake Problem Help

[wipeout]

Hi,

Been trying to get my brakes going this last week. I bled the master cylinder, and bled all of the calipers like 3 times over. Still I have a very soft peddle and the brake light comes on.

I have noticed that when I press on the brake pedal the engine rpm go up slightly by a couple of hundred rpm's. Could the brake booster be done. vacuum leak? I did check the line running from the booster to the carb and it looks good. Any ideas would be great. thanks.

 

[The73vetteman]

Is the car pulling to one side under braking? If it is that gives you a clue theres some air in the system.

Any leaks evident at the calipers?

I'd focus on getting all the air out before I worried about the master cylinder. You are bleeding from the furthest point first, aren't you? Bleeding these cars can be awkward.

 

[Eden72Vet]

I just had brake trouble this week myself. I bled my brakes when I worked on them a year ago, and I got a good pedal, but, not great. Last week it got softer, so I had a shop use a power bleeder, now I have the best pedal I have had since I owned the car (I hope it will stay, although I think I will be replacing the master cyclinder and other parts this winter). My advice, if you know someone or can get someone to power bleed it cheap, I would try that before I spent a bunch of money on all the other possibilities. I know I was skeptical and didn't think a power bleeder could do anything more than I could with a little time.

Hope this helps a little,

 

[wipeout]

So far I have gravity bled the rear calipers. And then I did the old brake bleed routine. Still dont have any brakes.

I have new brake lines all around and new flex hoses. No brake fluid is leaking anywhere. Still havent gravity bled the front yet doing it now. But im kinda thinking it wont do nothing. When I push on the brake pedal brake fluid shoots up into the air from the master cylinder and the brake pedal is super hard.

But nothing once I turn the car on. Thinking im gonna have to pressure bleed. them. Let you know how it is once I do the front I guess.

 

[wishuwerehere82]

Gravity bleeding won't do it. get someone to step on the pedal while you crack open the bleeders. There will be a big change.

 

[wipeout]

I've already done the brake bleed technique like 5 times. I read a post on CAC that jacking up one side of the car and gravity bleeding and then brake bleeding might work. Well see I guess.

 

[wishuwerehere82]

Don't forget that your calipers have pistons on both sides of the caliper. You have to bleed both sides to get the air out, otherwise there will still be air in the other side. Some only have bleeders on the outside one.
The order to bleed them is right (passenger side) rear, inside and outside.
Left rear, inside and outside.
Right front.
Left front.
You may have to stomp on the pedal a few times hard to get the brake light to go off once you have pedal pressure, the switch in the proportioning valve tends to stick once engaged.