poor brakes, help

amy

Hi,
72 Skylark factory drum brakes all around. I bled the brakes to change out the fluid, which it seems is recommended every few years and was probably not done in many years before I aquired this car.

Anyway the brakes were weak after having bled them, so I bled them again, still weak, I figured maybe a bleeder screw or two were bad. So I got 4 new bleeder screws that have a ball to prevent air backing in "speed bleeders" for one man brake bleeding. I bled weverything real good beginning with the farthest from the master cyl and ending closest, all my fluid is clean and new now.
HOWEVER...my brakes still suck! The pedal has very little resistance and all my stopping power is in the last inch or so of pedal throw. Kind of dangerous. What can I do?

Thus car has never had discs so it should not have the button that needs to be pushed while bleeding on the brake "manifold".

help

Check your brake adjustment. If they are too loose, your pedal travel will suck.

have you taken the drums off?


Originally Posted by buick64203have you taken the drums off?

First thing to do! You may have bad brakes, you may have gotten brake fluid in there, lots of things that looking could tell you.
What were the brakes like prior to bleeding?

I had the same situation.
4 wheel drums... pedal would go almost all the way to the floor.
I had the shoes adjusted up nice and snug...bled them but still not a nice pedal.

It wasnt until I noticed brake fluid on the floor.  One rear wheel cylinder was bad.  I bought 2 new ones for the rear and replaced both.  Turns out both were leaking.

Figured I check the front, no real signs of a leak but the paint on the shoes was bubling like paint stripper where it meets the wheel cylinder pistons.  Changed them out too.

Then I bled the system myself.  I dont have a "one man brake bleeder" so I started furthest from the master cylinder and just opened the bleeder screw until the fluid dripped.  I let it drip for a good 20 - 30 min's  per wheel while keeping the master cylinder topped up until clean fluid came out of each wheel.  (gives you time to clean up the garage)

What a difference.. a much better pedal now.

Might as well put a spring kit in while you have it appart!

Forgot to mention when the pedal does get to the bottom where it actually takes some effect, the brake light comes on, this makes me think it isnt a mechanical springs and shoes prob. (?)

The brakes were good before I bled them out of maintenance.
I have had the back ones off a few times just to inspect whenever I removed the wheels, like when I removed the wheels just to make it easier to bleed the brakes, They look fine, shoes are good for a while yet, I acn hear them move when I push the pedal in a quiet garage. I haven't had the fronts off, mainly just laziness as the bearing has to be addressed to get them off right? They all worked great before I bled them (dang it!).
My brother had said I should get disc because they work so much better, but I said these work fine, I was actaually impressed with the drum performance since they have such a bad rep.

I had an old Caprice once that had a master cyl going bad and you had to double pump it to get perssure, that doesn't do anything for me here on the Buick.
Does vacuum play a part?

Sounds like the master cylinder pooped out when bleeding. Fairly common when the piston in the master goes farther than it ever has.

That sounds like a pretty good guess to me also, since pretty much everything has remained unchanged.
Devon


Originally Posted by BUICKRATSounds like the master cylinder pooped out when bleeding. Fairly common when the piston in the master goes farther than it ever has.

Really, I need a new master cyl? Is there some sort of confirmation I can do or is that pretty much the only verdict?

thanks


Originally Posted by buicksForgot to mention when the pedal does get to the bottom where it actually takes some effect, the brake light comes on, this makes me think it isnt a mechanical springs and shoes prob. (?)

The brakes were good before I bled them out of maintenance.
I have had the back ones off a few times just to inspect whenever I removed the wheels, like when I removed the wheels just to make it easier to bleed the brakes, They look fine, shoes are good for a while yet, I acn hear them move when I push the pedal in a quiet garage. I haven't had the fronts off, mainly just laziness as the bearing has to be addressed to get them off right? They all worked great before I bled them (dang it!).
My brother had said I should get disc because they work so much better, but I said these work fine, I was actaually impressed with the drum performance since they have such a bad rep.

I had an old Caprice once that had a master cyl going bad and you had to double pump it to get perssure, that doesn't do anything for me here on the Buick.
Does vacuum play a part?

My light brake warning light would come on too...
Just check the wheel cylinders for piece of mind.  Remember brake fluid removes paint so if any paint on the shoes is bubbled, there is fluid coming from somewhere.
Try the drip method of bleeding each wheel at a time.  worked well for me.. but I had the time to do it.
I don't remember having to take off the bearings on the front to get the drum off.

First off, I've found the best way to bleed brakes is with a second person to work the brake pedal. Self bleeders are great but air can get sucked in past the bleeder threads. If there is no and I repeat NO air in the system (good healthy shots of fluid only), the brakes are adjusted properly and all the wheel cylinders are functioning normally (not siezed/binding) then most likely the master is bad. Especially if there is no fluid loss along with the soft pedal. Masters are also known the leak out the back...unbolt the master from the booster, pry it forward a bit and check for fluid back there.


Originally Posted by cstanley-gsI don't remember having to take off the bearings on the front to get the drum off.

Well, I just know from looking at this point it seems the only thing that could possibly be holding on the front drums is the nut that holds the bearing in. The wheel studs are short and are mounted to the drum.
Not normal? Does anyone else have some like I described?

I do know there is zero fluid leaking at the master or booster, or rear brakes. If any is up front inside the drum it is so small it never lowered the level or came out visibly.

Is there a good write up on the forum for bench bleeding / installing a master cyl?
Since I called the parts store and a reman master is only $20 I will go that route, I can them paint my booster while the master is out too. ;)


Originally Posted by buicksWell, I just know from looking at this point it seems the only thing that could possibly be holding on the front drums is the nut that holds the bearing in. The wheel studs are short and are mounted to the drum.
Not normal? Does anyone else have some like I described?

I do know there is zero fluid leaking at the master or booster, or rear brakes. If any is up front inside the drum it is so small it never lowered the level or came out visibly.

Is there a good write up on the forum for bench bleeding / installing a master cyl?
Since I called the parts store and a reman master is only $20 I will go that route, I can them paint my booster while the master is out too. ;)You do not need to take off the bearings.
Take a look at this thread
showthread.php?t=177944

Basically the question was here..

Which is the rear and which is the front drum
Rear is on the right
Front is on the left

Notice no lugs.  They stay on the hub when you slide the drum off.
It can be tight so back off the shoes with the self adjuster and take your time, it will come off.

Mine look more like these, but are steel. Could someone have put 69 style on my 72?

ebaymotors/67-68...fAcc  essories

Sheesh am I confused... how many kinds did they use? I think I have some whacked hybrid on my car.

See the ones that turbo Archie posted in another thread here....
attachment.php?at...3amp;d=1241806386

Mine are like that as far as the studs go, but I swear the drum body looks like the smaller of the two drums you posted in this thread. I will have to get a pic later of my actual car.

Im pretty sure fronts are the bigger drums cause they do most of the stopping.
In the auction you posted Im pretty sure the hub can be removed from that drum.  A lot of times the center hub centric opening on the drum is rusted onto the hub.  But it will come off

Are they attached in the ones in Turbo Archies pic? Seems I have an adventure before me when I tear into mine...

If possible, get a NEW master, not a rebuilt. I have had too many rebuilts puke on the bench. Reason being is the bore is honed to slight oversize and stock size pistons/seals are used in the rebuild. A great recipe for failure.

This is my front drum, studs appear built in to drum, and it houses the bearing. Is this odd for a 1972?

Looks just like mine.
Here is the only pic I have of when I started cleaning and painting....
I admit the lugs look like they are one with the drum but are not.

did your master ever go dry while you were working on the brakes??  sounds to me that you have some air in the prop valve........get a seccond person to help you bleed them.

my 72 had 1 piece front drums..........I will let curtis try to get one apart if he so desires..........

Generally the hubs are pressed into the front drum.  If they come apart as shown above, someone at some point has broken the hubs loose from the drum.  They should be re pressed onto the drum if separated.  The master cylinder is a good suggestion as when the piston is operated beyond where it has worn, problems result.  I would also pull the drums and check each of the individual wheel cylinders for leakage.  Yes, you have to "mess" with the bearing but it really isn't a big deal.  Just clean them in some solvent, check the bearing surfaces for wear, and repack them with grease.  You should inspect them periodically anyway.

The other problem area could be your brake hoses, 2 front, one rear.  They can look fine from the outside and be plugged internally.  If you were getting good fluid flow from each bleeder valve, they are probably OK.  If you weren't getting good flow, I'd replace them.  They aren't very expensive.

I know it doesn't seem like you were rewarded for being diligent and changing the brake fluid but  for you.  You are discovering problems that were there before but disguised.  Doing a complete brake inspection should be part of changing the fluid.  If your master is in good condition, the wheel cylinders are good, the hoses open and clear, and the brakes adjusted properly, they should bleed with no further problems.  Vacuum Pumps don't seal very well on the bleeder screws so find a buddy to help you bleed the brakes the old fashioned way.  Good luck!

Greg

Regardless of what (probably master cylinder) is causing your problem, change the three, two front, and one rear rubber brake hoses as well.