Ever damange your brake master cylinder from pushing the pedal in too far?
02-26-2007, 07:14 PM
#1
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Ever damange your brake master cylinder from pushing the pedal in too far?
Helped my buddy do a full tune up on his new-to-him '99 FRC w/ 55k and bone stock. It had stock brake fluid and stock pads still. We fully flushed the system and put new pads in.
Today he was greated with a nice leak from the master between the booster and master housing and a nice puddle on the floor.
He did some research and found that when using a manual bleed w/ a "one man" type setup you are moving the pedal farther than it's "normal" range of operation and this can damage the seals.
I've never heard of this... I've bled my brakes 1000x and always simply crack the bleed screw and pump away. I use a blastic bottle w/ clear tubing and brake fluid in the bottom to seal the system... a homemade one make bleeder setup. Works great. When I'm on the last pump I push the pedal on the floor and have my assistant (whomever that may be) close the bleed screw, actually normally the assistant is pumping and I'm working the calipers etc.
On my father's '04 we've done the same thing... even before learning how to setup a bleed bottle properly I was using speed bleeders and pushing the pedal to the floor.
Before speed bleeders using the 2-man method I'd crack bleeder, partner push pedal to floor, close bleeder, then release and repeat.
Again... no issues... I'm confused.
Today he was greated with a nice leak from the master between the booster and master housing and a nice puddle on the floor.
He did some research and found that when using a manual bleed w/ a "one man" type setup you are moving the pedal farther than it's "normal" range of operation and this can damage the seals.
I've never heard of this... I've bled my brakes 1000x and always simply crack the bleed screw and pump away. I use a blastic bottle w/ clear tubing and brake fluid in the bottom to seal the system... a homemade one make bleeder setup. Works great. When I'm on the last pump I push the pedal on the floor and have my assistant (whomever that may be) close the bleed screw, actually normally the assistant is pumping and I'm working the calipers etc.
On my father's '04 we've done the same thing... even before learning how to setup a bleed bottle properly I was using speed bleeders and pushing the pedal to the floor.
Before speed bleeders using the 2-man method I'd crack bleeder, partner push pedal to floor, close bleeder, then release and repeat.
Again... no issues... I'm confused.
02-26-2007, 08:04 PM
#4
Le Mans Master
Helped my buddy do a full tune up on his new-to-him '99 FRC w/ 55k and bone stock. It had stock brake fluid and stock pads still. We fully flushed the system and put new pads in.
Today he was greated with a nice leak from the master between the booster and master housing and a nice puddle on the floor.
He did some research and found that when using a manual bleed w/ a "one man" type setup you are moving the pedal farther than it's "normal" range of operation and this can damage the seals.
I've never heard of this... I've bled my brakes 1000x and always simply crack the bleed screw and pump away. I use a blastic bottle w/ clear tubing and brake fluid in the bottom to seal the system... a homemade one make bleeder setup. Works great. When I'm on the last pump I push the pedal on the floor and have my assistant (whomever that may be) close the bleed screw, actually normally the assistant is pumping and I'm working the calipers etc.
On my father's '04 we've done the same thing... even before learning how to setup a bleed bottle properly I was using speed bleeders and pushing the pedal to the floor.
Before speed bleeders using the 2-man method I'd crack bleeder, partner push pedal to floor, close bleeder, then release and repeat.
Again... no issues... I'm confused.
Today he was greated with a nice leak from the master between the booster and master housing and a nice puddle on the floor.
He did some research and found that when using a manual bleed w/ a "one man" type setup you are moving the pedal farther than it's "normal" range of operation and this can damage the seals.
I've never heard of this... I've bled my brakes 1000x and always simply crack the bleed screw and pump away. I use a blastic bottle w/ clear tubing and brake fluid in the bottom to seal the system... a homemade one make bleeder setup. Works great. When I'm on the last pump I push the pedal on the floor and have my assistant (whomever that may be) close the bleed screw, actually normally the assistant is pumping and I'm working the calipers etc.
On my father's '04 we've done the same thing... even before learning how to setup a bleed bottle properly I was using speed bleeders and pushing the pedal to the floor.
Before speed bleeders using the 2-man method I'd crack bleeder, partner push pedal to floor, close bleeder, then release and repeat.
Again... no issues... I'm confused.
- Our 99 FRC MC is still going strong at 127,000It is a very rare occurrance from bleeding operation in my experience - wait till he tapers those pads and trys to stop that thing - I guarantee the pedal has been pushed harder at the end of the day!
It was time for the master cylinder to leak (zen method of car repair).
02-26-2007, 08:18 PM
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The car is mine, nice big puddle on the floor mid section of car.
It was pretty obvious from where it came, i cleaned up the area and drove it to the store and nothing has leaked more yet(2hrs), still dry. Going to let it sit again overnight before i go and order a MC. :crossing fingers:
Going to just drive around the area to put some use of the system to see if she starts to dribble again. But its bone dry at the moment, ran my finger accross the bottom lip and nothing. Which is weird because there was/is a lot of fluid on the floor for about a 16 hour period.
Ugh new cars and there hidden problems....gotta love it
It was pretty obvious from where it came, i cleaned up the area and drove it to the store and nothing has leaked more yet(2hrs), still dry. Going to let it sit again overnight before i go and order a MC. :crossing fingers:
Going to just drive around the area to put some use of the system to see if she starts to dribble again. But its bone dry at the moment, ran my finger accross the bottom lip and nothing. Which is weird because there was/is a lot of fluid on the floor for about a 16 hour period.
Ugh new cars and there hidden problems....gotta love it
02-26-2007, 10:20 PM
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Helped my buddy do a full tune up on his new-to-him '99 FRC w/ 55k and bone stock. It had stock brake fluid and stock pads still. We fully flushed the system and put new pads in.
Today he was greated with a nice leak from the master between the booster and master housing and a nice puddle on the floor.
He did some research and found that when using a manual bleed w/ a "one man" type setup you are moving the pedal farther than it's "normal" range of operation and this can damage the seals.
I've never heard of this... I've bled my brakes 1000x and always simply crack the bleed screw and pump away. I use a blastic bottle w/ clear tubing and brake fluid in the bottom to seal the system... a homemade one make bleeder setup. Works great. When I'm on the last pump I push the pedal on the floor and have my assistant (whomever that may be) close the bleed screw, actually normally the assistant is pumping and I'm working the calipers etc.
On my father's '04 we've done the same thing... even before learning how to setup a bleed bottle properly I was using speed bleeders and pushing the pedal to the floor.
Before speed bleeders using the 2-man method I'd crack bleeder, partner push pedal to floor, close bleeder, then release and repeat.
Again... no issues... I'm confused.
Today he was greated with a nice leak from the master between the booster and master housing and a nice puddle on the floor.
He did some research and found that when using a manual bleed w/ a "one man" type setup you are moving the pedal farther than it's "normal" range of operation and this can damage the seals.
I've never heard of this... I've bled my brakes 1000x and always simply crack the bleed screw and pump away. I use a blastic bottle w/ clear tubing and brake fluid in the bottom to seal the system... a homemade one make bleeder setup. Works great. When I'm on the last pump I push the pedal on the floor and have my assistant (whomever that may be) close the bleed screw, actually normally the assistant is pumping and I'm working the calipers etc.
On my father's '04 we've done the same thing... even before learning how to setup a bleed bottle properly I was using speed bleeders and pushing the pedal to the floor.
Before speed bleeders using the 2-man method I'd crack bleeder, partner push pedal to floor, close bleeder, then release and repeat.
Again... no issues... I'm confused.
It is known to happen...it is best to place a block of wood behind the brake pedal to prevent excessive stroke of the master cylinder when bleeding.
Hammer
02-26-2007, 10:28 PM
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^ Very interesting... I've bled so many times on multiple cars and never had a problem... I'll use a block of wood from now on.
Vinny... On corvettemechanic a guy replied that using a pressure bleeder he had a leak in that area, then never again.
Vinny... On corvettemechanic a guy replied that using a pressure bleeder he had a leak in that area, then never again.
02-27-2007, 12:14 AM
#11
Safety Car
it happens in certain situations.
your system was never bleed - maintained before,, so at the end of the normal stroke, the piston develops a buildup of gunk.
Now you come along, push the pedal all the way to the floor, and the gunk rips the seal.
I'd change it, because you don't want to find out at the track.
your system was never bleed - maintained before,, so at the end of the normal stroke, the piston develops a buildup of gunk.
Now you come along, push the pedal all the way to the floor, and the gunk rips the seal.
I'd change it, because you don't want to find out at the track.
02-27-2007, 01:54 AM
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I'll see how it goes tomorrow, i dont daily the car by any means.
If it's not seeping at all anymore im not going to worry about it. Once i break in the pads and rotors some more....ill get on the brakes hard a few times for a real test.
As for the track comment, no plans for the track as of yet. The MC is 185 bucks, which isnt bad. But i just dropped a decent amount on the tuneup, on top of all the other buying expenses, I'd like not to spend anymore then i have to at the moment. Not made of money like some of you guys
If it's not seeping at all anymore im not going to worry about it. Once i break in the pads and rotors some more....ill get on the brakes hard a few times for a real test.
As for the track comment, no plans for the track as of yet. The MC is 185 bucks, which isnt bad. But i just dropped a decent amount on the tuneup, on top of all the other buying expenses, I'd like not to spend anymore then i have to at the moment. Not made of money like some of you guys
02-27-2007, 08:51 AM
#13
Le Mans Master
Most times when I've seen a damaged MC (perhaps from pushing the pedal to the floor), the seals are damaged, then you get a pedal that slowly moves to the floor, limiting the pressure you can apply to the brakes (the fluid is leaking past the damaged seal). Then the fluid works its way back to the MC/booster joint and leaks out there.
But, it's usually a fairly small amount of fluid.
Bottom line: if you've got a firm brake pedal that you can hold for several seconds, your MC is probably OK.
HTH, and have a good one,
Mike
But, it's usually a fairly small amount of fluid.
Bottom line: if you've got a firm brake pedal that you can hold for several seconds, your MC is probably OK.
HTH, and have a good one,
Mike
02-27-2007, 10:31 AM
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well to update this, i checked this morning and no signs of more fluid. So ill just be sure to keep a good eye on where it was coming from and also the fluid level.
vettedrmr : My other car is a 1990 integra, and they are notorious for the internal pistol seal to leak, which causes the pedal to the floor syndrom. But this seemed like the exteral seal was leaking, which it very well could have been when going all the way to the floor. We moved about a quart and a half of brake fluid through the system that day....so there's no telling whats going on without taking the MC off.
vettedrmr : My other car is a 1990 integra, and they are notorious for the internal pistol seal to leak, which causes the pedal to the floor syndrom. But this seemed like the exteral seal was leaking, which it very well could have been when going all the way to the floor. We moved about a quart and a half of brake fluid through the system that day....so there's no telling whats going on without taking the MC off.
02-28-2007, 05:25 AM
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Le Mans Master
02-28-2007, 09:25 AM
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