Spongy Brake Pads - (Calipers?)

[GreyGoose006]

1 Pedal push to the floor? or more then that?

NEVER push the pedal in all the way if you want to keep your master cylinder working.

the reason for this is that during everyday driving, the piston only travels a few inches into the master cylinder, meaning that only a few inches ever gets cleaned off and the rest gets dirty and rusty and corroded. if you push the pedal to the floor, you are introducing all this nasty junk into your brake system and will probably have to replace your master cylinder and change all the fluid. a better way is to place a 2x4 under the pedal, and pump that way, so the pedal never gets to travel too far.

unless you have a rather new car that requires you to push the pedal all the way in to get it out of park, you shouldnt floor the pedal when bleeding. steady pulses work best.

[KiwiBacon]

Originally Posted by GreyGoose006

NEVER push the pedal in all the way if you want to keep your master cylinder working.

the reason for this is that during everyday driving, the piston only travels a few inches into the master cylinder, meaning that only a few inches ever gets cleaned off and the rest gets dirty and rusty and corroded. if you push the pedal to the floor, you are introducing all this nasty junk into your brake system and will probably have to replace your master cylinder and change all the fluid. a better way is to place a 2x4 under the pedal, and pump that way, so the pedal never gets to travel too far.

unless you have a rather new car that requires you to push the pedal all the way in to get it out of park, you shouldnt floor the pedal when bleeding. steady pulses work best.

If your MC is in that state, you'd be an idiot not to deal with it right then.

Most of them time seal kits are cheap, a simple hone out with sandpaper wrapped around your fingers will clean out the bore.

Otherwise you're dancing with death the first time you have to really stand on the pedal with your dodgy master cylinder. Brakes are something it's worth not cutting corners on.

[GreyGoose006]

right, but the average person stands on the brakes how often?
unless you have to floor the pedal to get the thing out of park, then even a relatively new master cylinder could be in this state in a short ammount of time.

what i am saying is that why intentionally (or unintentionally) do damage to your master cylinder if it is otherwise in fine condition.
it dosent take lots of wear or time for the piston to degrade and get dirty to the point that it could do damage to the seals.
if you replaced a master cylinder each time the piston got dirty and corroded, you would probably go thru one a year.

its just a preventative measure that could save your braking system a lot of undue wear.

[KiwiBacon]

I've just overhauled the MC in my car. last time I had it out and apart was three years ago, the vehicle is now 21 years old.

The bore is in perfect condition all the way down, but there was a little corrosion at the entry point.

[UncleBob]

the issue with stressing the master, is when you have some form of brake assist, and the vehicle is running. The assist multiplies your force input, so when you stand on the peddle as hard as you can, the multiplication equates a extremely high amount of force that has a risk of damaging the pressure cups in the master, which are only rubber. Over the long run it accelerates wear of the cups and eventually they start leaking

Master's don't fail terribly often, and IMO most failures are due to fluid contamination. Its hard to quantify what causes what to fail, but if I personally had to make the choice of slamming on the brakes super hard, and not stopping in time, I think I know which one I would pick every time

[GreyGoose006]

so for those of us who dont know,
how often should you change your brake fluid?

[curtis73]

I do it with every pad/shoe change. I get lazy sometimes and do it every other. The recommendation is something crazy like every 6 months.

[bobss396]

Are you losing fluid now? If so, look for a loose brake hose at one or both of the calipers. It may have been just cracked enough to let some air in. A good brake mechanic will always check the brake hoses when he puts the calipers back on.

In good faith he should go around the car and bleed the whole system at no charge. This should have been caught in HIS test drive after the brake job. I don't suspect a master unless it is either "bypassing" or sinking to the floor with no recovery. Look for a brake fluid trail down the firewall.

To give your self a better pedal hight overall, make sure that the rear shoes and or emergency brake cable is in good adjustment. Many people don't know it, but the rear brake (on drums only) adjustment is where you get your pedal height from.

Bob

[bobss396]

Originally Posted by GreyGoose006

NEVER push the pedal in all the way if you want to keep your master cylinder working.

the reason for this is that during everyday driving, the piston only travels a few inches into the master cylinder, meaning that only a few inches ever gets cleaned off and the rest gets dirty and rusty and corroded. if you push the pedal to the floor, you are introducing all this nasty junk into your brake system and will probably have to replace your master cylinder and change all the fluid. a better way is to place a 2x4 under the pedal, and pump that way, so the pedal never gets to travel too far.

unless you have a rather new car that requires you to push the pedal all the way in to get it out of park, you shouldnt floor the pedal when bleeding. steady pulses work best.

You are right about that. Every master has a ring of rust and crud beyone the normal piston travel range. I was taught to never bottom out the pedal when I was bleeding brakes, most of which were done with a pressure bleeder so we only had to pump the pads out against the rotors.

Bob

[GreyGoose006]

The recommendation is something crazy like every 6 months.

yeah, that is crazy.
i guess i need to do it then.

[1mmueller]

Originally Posted by CyberFyber

Hi there,

My '95 Suzuki Sidekick was driving mighty fine with no problems in braking 'cept for a faint meshing noise which started last week. I researched this and figured it was the pads. Okay.

So I took it to the mech down the block and he replaced the pads. Well, thereafter the brakes have been rather spongy. So I took it back now after several days of driving to see if the pads will adapt (they didn't).

I'm now being told that Hey! It might be the calipers or something else?

MY QUESTION? why isn't this something which would've been caught the first time around?

They tell me: "Well, how are we to know?"

Can someone please enlighten me regarding this?

Did you ask for a full brake inspection from the get go or did you go in just for new pads as you say you researched?
Im not saying your vehicle fits this but when you have brakes that are very worn they tend to not need as much caliper movement to grab the rotors. Sometimes replacing the pads will make the pedal feel "limper".
If in your "feet" you feel the pedal is too soft I would suggest a full brake inspection, but beware sometimes you get what you pay for on the free ones.
Air in the lines is not likely, and remember you have rear brakes also.

www.OBD2Scanners.com

[donram360]

check to be sure that the pads are seated in the calipers. If one slipped out the "sponge" may be the whole pad, metal backing and all flexing and not having full contact with the rotors.

[CyberFyber]

Well,

I took it to M*DAS last week whom over the years still hadn't done me wrong. They inspected the brakes and all to be sure they were safe and said there was nothing wrong with them. Hehe, yah, sure....but they didn't drive the car and sent me on my way cause they had to close up.

WHAT I DON'T GET, is this. The guy there I talk to is convinced that if they check it inside the garage without driving it anyplace then there's absolutely nothing wrong with the brakes. No Air, nothing. But that's not the impression I'm getting from this thread.

I mean, CAN YOU? Are you able to tell there's no air inside there just by inspecting it inside the garage? Or is it that this guy at the front desk doesn't know half as much as he thinks he does?

.....'And NOW I've got this other guy at Str**ss telling me on the phone that the estimate would be $170 to do the bleed and new brakes "since there's no other way of bleeding without removing the calipers and such and thus this is what the cost would be".

Ugggggghhhhhhhhhhh.

BTW, it doesn't help when a Mech (m*das) makes you feel silly for bringing in a car as if you were a worry-wart. I've already had two other family members drive the car and they agree with my findings.

[UncleBob]

absolutely untrue, you can not accurately diagnose a brake issue without driving a car. If there's something obvious that can be found in an inspection, thats one thing, but not all things are easily found just by looking at them.

Brake bleeding does not require removal of anything.

[Moppie]

CyberFyber, have you tried, or are you interested in trying to bleed the brakes yourself?
Its actually a very simple operation providing you follow some simple instructions to the letter.