willj

well this is the story, car is a 65 starfire. pedal is hard 95 % of the time ,comes to a stop slow and easy ,can not lock up tires ,even in dirt,this is the second master and power booster I have put on , acts the same with both , every thing else is new , so I tried a vacuum canaster, with a gage, and it reads 22 pounds, when I press on brake it goes down to 15 pounds,i have done all I can think of,i am at a dead end . any idea,s would be appreciated, thanks in advance . will

oldcutlass

How long ago were the shoes replaced?

MDchanic

Yes, what's inside those drums?

And how much vacuum is 22 pounds???

- Eric

Sugar Bear

Pull the wheels and drums to look for seized wheel cylinders.

MDchanic

... or leaky ones.

With enough accumulated brake dust, a wheel cylinder can weep a surprising amount of brake fluid without the wheel ever looking wet on the outside.

Also, don't forget brake fluid soaked shoes.

- Eric

willj

thanks very much for all the replys, on the inside of the drums ,all is new, and there are no wheel cylinder leaks.everything is new,lines and all . I will try and bleed again , but I have done this a few times , again appreciate the help ,will

willj

hi, to answer the vacuum question, it is 20. I did check the valve on the powerbooster, works as it should . also pressed down on brake pedal , and started car , the pedal did go go down alittle ,not much ,but did move . thanks again,will

76olds

Can you post a pic here of the rear springs/wheel cylinder set-up when you have the drums off again?

MDchanic

Also, do you have good flow of brake fluid through each bleeder when open?

I strongly agree with pictures - are you sure that the correct shoes are in the correct positions (primary & secondary) and that they are adjusted correctly?

- Eric

oldcutlass

Also if new shoes were placed on uncut drums, they would take some time to settle in.

Professur

When you say 'everything else is new' exactly what do you mean by everything? Rubber lines? Hard lines? Fresh clean fluid to all four corners? How were things before you started fixing them? Did it ever brake right? MD has said my first thought ... grab a buddy and check flow at all four corners.

willj

as far as what is new ,I guess 4 years ago every piece of the brake system was new, the brakes have never worked right. every so often , they will work for a little bit, like 2 or 3 presses on the pedal, then back to regular.when I got the car it was not running ,took completely apart,in 2007.got it back together 2 years ago,do to some health reasons , things go slow sometimes, I am waiting for someone to stop by, and I will ckeck the fluid to all for wheels, thanks all. will

Firewalker

Might be something else, but that could be the wrong size master cylinder bore or the wrong size wheel cylinder bores or both.

Bigger master cylinder bore causes harder braking and harder peddles. A smaller bore on the wheel cylinders will as well. That pedal should be soft locking the tires up just before it gets to the floor.

Sampson

Check the linkage from the pedal to the master cyl. I wonder if there is something restricting the travel since you say it works sometimes.

Firewalker

Your post, to him, made me think maybe the adjuster on the booster going into the new master cylinder is not screwed out from the booster the right amount to push the master cylinder's piston in right (far enough).

willj

well got it fixed , the fist two master cylinders where remanufactured, I won,t say where I got them, but tried one more from fusick ,it was a reobestes, excuse the spelling, but it cured the problem after two years of problems ,if it means anything ,it said that this one was a new one ,not rebuilt,but I do thank everyone in all the help I received ,I learned very much, thanks again to all ,will.

MDchanic

Why won't you tell us where you got the bad ones, and what brand they were, so that we might avoid the same problem?

- Eric

Firewalker

What a great feeling you must have, and every time you hit the brakes from now on

76olds

X2 a heads up on where you purchased them, this helps all us members out. Its about everyone helping everyone here.
So ????
Cheers
Eric

Don R.

Glad you found the problem! Its unfortunate but very common that rebuilt brake parts are no good, I learned this years ago the hard way. Always go with name brand new if they are available.

Firewalker

The biggest problem in my view is not getting the right size bore. A bigger bore than was in there makes the brakes hard with less power to the brake pads, for the same peddle push. You can not depend on others to know this and give you the right size. Also today many think bigger is better and that soft or spongy brakes are bad.

I had to learn this lesson years ago on mine and it wasn't an Olds. The softness at the peddle is because they are working harder, with less effort on the peddle. The peddle travels further also with smaller.