Master Brake Cylinder OR Booster???
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From: Sioux Falls SD
Master Brake Cylinder OR Booster???
Hope you guys can shine some light on this for me.
1994 LT1 coupe. Stock breaks.
Problem: Breaks are all but gone.
My guess: I'm 99.9% sure the problem is my Master Brake Cylinder, or my Brake booster But can't get a satisfying answer on which.
Symptoms:
Top most of my peddle is a soft sponge. But half way (or more) turns into a rock.
Brakes work ok if pressing hard in the Hard part of the peddle movement.
A bit of a squishing sound (like liquid in a faulty hydraulic cylinder) heard from the master cylinder/booster area when i press the brakes lightish.. goes away when I push hard.
Facts:
New brake pads all around (this problem soon after)
New rotors rear, turned front
Zero brake fluid any where!
Reservoir 100% full and has always been there.
So I know I have to replace one of these to.. but would like to replace only the correct one... just don’t feel like throwing parts at the thing.
So advice, guesses, questions all welcomed.. thanks again guys!
1994 LT1 coupe. Stock breaks.
Problem: Breaks are all but gone.
My guess: I'm 99.9% sure the problem is my Master Brake Cylinder, or my Brake booster But can't get a satisfying answer on which.
Symptoms:
Top most of my peddle is a soft sponge. But half way (or more) turns into a rock.
Brakes work ok if pressing hard in the Hard part of the peddle movement.
A bit of a squishing sound (like liquid in a faulty hydraulic cylinder) heard from the master cylinder/booster area when i press the brakes lightish.. goes away when I push hard.
Facts:
New brake pads all around (this problem soon after)
New rotors rear, turned front
Zero brake fluid any where!
Reservoir 100% full and has always been there.
So I know I have to replace one of these to.. but would like to replace only the correct one... just don’t feel like throwing parts at the thing.
So advice, guesses, questions all welcomed.. thanks again guys!
Last edited by meliudaj; Oct 25, 2004 at 07:31 PM.
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Originally Posted by meliudaj
Hope you guys can shine some light on this for me.
1994 LT1 coupe. Stock breaks.
Problem: Breaks are all but gone.
My guess: I'm 99.9% sure the problem is my Master Brake Cylinder, or my Brake booster But can't get a satisfying answer on which.
Symptoms:
Top most of my peddle is a soft sponge. But half way (or more) turns into a rock.
Brakes work ok if pressing hard in the Hard part of the peddle movement.
Facts:
New brake pads all around (this problem soon after)
New rotors rear, turned front
Zero brake fluid any where!
Reservoir 100% full and has always been there.
So I know I have to replace one of these to.. but would like to replace only the correct one... just don’t feel like throwing parts at the thing.
So advice, guesses, questions all welcomed.. thanks again guys!
1994 LT1 coupe. Stock breaks.
Problem: Breaks are all but gone.
My guess: I'm 99.9% sure the problem is my Master Brake Cylinder, or my Brake booster But can't get a satisfying answer on which.
Symptoms:
Top most of my peddle is a soft sponge. But half way (or more) turns into a rock.
Brakes work ok if pressing hard in the Hard part of the peddle movement.
Facts:
New brake pads all around (this problem soon after)
New rotors rear, turned front
Zero brake fluid any where!
Reservoir 100% full and has always been there.
So I know I have to replace one of these to.. but would like to replace only the correct one... just don’t feel like throwing parts at the thing.
So advice, guesses, questions all welcomed.. thanks again guys!
Since you seem to have both symptoms(soft on top, hard at bottom) and seem to have just recently done or had brake work done, I would start with a good and thorough bleed of the system.
Also, generally, but not always, a bad vacuum booster will emit a "hiss" when pressure is applied to the pedal.
I am betting IMHO, a thorough brake bleed may solve the problem
seeya
Jack
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From: Sioux Falls SD
Originally Posted by jackdaroofer
Since you seem to have both symptoms(soft on top, hard at bottom) and seem to have just recently done or had brake work done, I would start with a good and thorough bleed of the system.
Jack
Do you think air could get in my system from replaceing Pads and rotors??? Did it my self... I guess I don't see how. But not marking it off as not possible.
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I agree it doesn't seem likely, but before I started replacing major stuff, I would do the bleed!
If you have vacuum test equipment, you probably could pull a vacuum test on booster to see if it is holding vacuum.
What concerns me is the "rock hard" pedal at the lower end. My experience with bad MC's is pedal never gets rock hard and goes all the way to the bottom unless you pump the heck out of it.
Sorry I can't be more definitive, but like you, I don't want to waste your money.
A full system bleed is cheap. Have someone step on the brakes a lot as you listen for vacuum leaks around the booster
Jack
If you have vacuum test equipment, you probably could pull a vacuum test on booster to see if it is holding vacuum.
What concerns me is the "rock hard" pedal at the lower end. My experience with bad MC's is pedal never gets rock hard and goes all the way to the bottom unless you pump the heck out of it.
Sorry I can't be more definitive, but like you, I don't want to waste your money.
A full system bleed is cheap. Have someone step on the brakes a lot as you listen for vacuum leaks around the booster
Jack
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From: Sioux Falls SD
Originally Posted by CentralCoaster
Is your pedal spongy, or does it just seem that way because you hear the air rushing noise as you push down?
Replace your booster.
Replace your booster.
My feeling is that its spongy.... Actually has been feeling weaker and weaker... Thats what led me to doing brake pads and suck (they where needed as well)
I very much notice it even with the radio on and I can't hear the noise.
P.S. anyone good good leads on where to buy these parts.... Or some used ones they have to sell?
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Originally Posted by meliudaj
My feeling is that its spongy.... Actually has been feeling weaker and weaker... Thats what led me to doing brake pads and suck (they where needed as well)
I very much notice it even with the radio on and I can't hear the noise.
P.S. anyone good good leads on where to buy these parts.... Or some used ones they have to sell?
I very much notice it even with the radio on and I can't hear the noise.
P.S. anyone good good leads on where to buy these parts.... Or some used ones they have to sell?
First choice, the more you explain, is the MC!
Jack
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From: Sioux Falls SD
I'm really starting to think MC as well.. since I noticed that if I try and pump it lets say 2-3 times.. pumper number 3 is like a rock!!!! But the first push is soft, and can at times lead all the way to the floor.
So to other question... any suggestions/idea on good places to buy new/rebuilt/used?
So to other question... any suggestions/idea on good places to buy new/rebuilt/used?
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Suggest very strongly that you rule out "used", it may be a s bad or worse than yours.
Suggest strongly that you rule out "rebuilt"! Wear in the bore of the cylinder is the principal cause of failure. Rebuilding doesn't put metal back in the bore
Therefore, I would and have stuck with "new" I actually found mine on E bay a year or two ago. I hate to say this and maybe ashamed to admit, but I think a lot of new parts get stolen and
sold on e bay
I have bought a lot of new parts in GM/delco boxes, still in the plastic, at half price or less
Jack
Suggest strongly that you rule out "rebuilt"! Wear in the bore of the cylinder is the principal cause of failure. Rebuilding doesn't put metal back in the bore
Therefore, I would and have stuck with "new" I actually found mine on E bay a year or two ago. I hate to say this and maybe ashamed to admit, but I think a lot of new parts get stolen and
sold on e bay
I have bought a lot of new parts in GM/delco boxes, still in the plastic, at half price or less
Jack