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So i had my regular shop (a local goodyear) install my Stoptech front rotors and hawk pads (front only). While i was watching them i noticed the tech wiping fluid off the resivoir and surrounding area. I noticed the brakes seemed really spongey. I thought i was just supposed to be easy on them at first, so I never really locked them up. My mistake ( i know now there is a propper bedding procedure i was supposed to follow ). So last weekend i had an event where i really got to put the brakes to the test. No good, they were super soft, it totally blew my day. My buddys tested the pedal and agreed. They said i might need to bleed them properly. I brought the RL back to my shop and they tried to bleed them and told me my master cylinder was on its way out. Does this sound right? Could my shop have messed up the cyl? Any help would be appreciated.
 

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when you install new pads and rotors they are much thicker than the old pads and rotors. You must compress the calipers piston back into its bore. well the fluid in the line has to go somewhere. Back into the master cylinder. Now if someone poured more brake fluid into the master cylinder reservoir to bring the fluid to the correct level the fluid will pour out the top once you compress the calipers piston. Thats not the problem here though. What most likely happened IF they bled the brakes they pushed too far down on the brake pedal inside of the car. This causes the master cylinder's piston to travel further than it normally does. Now, there was probabaly corrosion on the piston and it destroyed the seals inside the master cylinder. If they bled the brakes they are responsible. Especially if the pedal sinks slowly to the floor and no brake fluid is leaking out. The fluid level should drop with no visible leaks whille pressing on the pedal. Sorry for the huge run on paragraph,lol
 

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when you install new pads and rotors they are much thicker than the old pads and rotors. You must compress the calipers piston back into its bore. well the fluid in the line has to go somewhere. Back into the master cylinder. Now if someone poured more brake fluid into the master cylinder reservoir to bring the fluid to the correct level the fluid will pour out the top once you compress the calipers piston. Thats not the problem here though. What most likely happened IF they bled the brakes they pushed too far down on the brake pedal inside of the car. This causes the master cylinder's piston to travel further than it normally does. Now, there was probabaly corrosion on the piston and it destroyed the seals inside the master cylinder. If they bled the brakes they are responsible. Especially if the pedal sinks slowly to the floor and no brake fluid is leaking out. The fluid level should drop with no visible leaks whille pressing on the pedal. Sorry for the huge run on paragraph,lol
he means change the master tbfu and no not their fault
 

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ok, if the brake pedal was spongy after they installed his pads and rotors and they bled them by pushing the brake pedal too far down it IS their fault. You are NOT supposed to do that. This is what makes sense to me especially if the brake pedal was firm before they installed the rotors and pads. Installing rotors and pads alone should not leave you with a spongey pedal hate to break it to you.
 

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ok, if the brake pedal was spongy after they installed his pads and rotors and they bled them by pushing the brake pedal too far down it IS their fault. You are NOT supposed to do that. This is what makes sense to me especially if the brake pedal was firm before they installed the rotors and pads. Installing rotors and pads alone should not leave you with a spongey pedal hate to break it to you.
There's no way to prove this happened.

Another way to tell - is the clutch spongy as well? They work off the same master cyl iirc, and I'd think if it was taking a crap it would also be spongy like the brakes.

I'd try bleeding the calipers again and see if that helps. It sounds like air got in the system.
 

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They just use the same fluid. There is still a clutch master cylinder. Just because the brake pedal is spongey doesnt mean the clutch pedal will be spongey. Also the brake master is higher up than the clutch master. And air bubbles rise so how could air get into the clutch master and past it into the line feeding the slave cylinder?
 

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Discussion Starter #10
they have been re-bled twice now. Same result. Im covered for the MC so i'll be ok. I just wanted to make sure it wasn't unneeded work. But rest assured i will not have my tire shop do any brake work for me again.
 

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ok, if the brake pedal was spongy after they installed his pads and rotors and they bled them by pushing the brake pedal too far down it IS their fault. You are NOT supposed to do that. This is what makes sense to me especially if the brake pedal was firm before they installed the rotors and pads. Installing rotors and pads alone should not leave you with a spongey pedal hate to break it to you.
MIkey no, BS. there is no such thing as pushing the pedal too far down when bleeding the brakes the assembly is designed to stroke to its intended parameters. Master cylinders dont last forever and find me ANYONE on this forum who intentionally changes (flushes) the entire system brake fluid capacity annually....as it should be.....Rare birds...
 

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Tell me this then. Do you ever push your brake pedal ALL the way down to the floor? I think not. If you do you have a problem. When bleeding brakes the pedal is not supposed to be pushed all of the way to the floor. There is gunk inside of the master cylinder that the piston never touches. And when it is pushed past its normal range of travel it messed up the seal. And , here's few sites specifically saying DO NOT let the pedal travel all of the way down to the floor.

1.Bleeding Brakes

2.How to Bleed Brakes - wikiHow

3.Car Maintenance 101: Bleeding your Brakes (Two-Person Brake Fluid Flushing) Auto Mechanic | Auto Mechanic Repair and Maintenance Tips

4. And here you go chief. If those three websites werent enough proof for you, this one specifically says you will be buying a new master cylinder once you push the pedal all of the way down to the floor while bleeding.

Brake Bleeding Tutorial, Tips and Pictures - Bleed Brakes Like You Mean It - Honda Tuning Magazine

Its in the text right under the picture of the master cylinder push rod. Next time you want to argue do your research and don't argue with an Auto Tech. :rofl:
 

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Tell me this then. Do you ever push your brake pedal ALL the way down to the floor? I think not. If you do you have a problem. When bleeding brakes the pedal is not supposed to be pushed all of the way to the floor. There is gunk inside of the master cylinder that the piston never touches. And when it is pushed past its normal range of travel it messed up the seal. And , here's few sites specifically saying DO NOT let the pedal travel all of the way down to the floor.

1.Bleeding Brakes

2.How to Bleed Brakes - wikiHow

3.Car Maintenance 101: Bleeding your Brakes (Two-Person Brake Fluid Flushing) Auto Mechanic | Auto Mechanic Repair and Maintenance Tips

4. And here you go chief. If those three websites werent enough proof for you, this one specifically says you will be buying a new master cylinder once you push the pedal all of the way down to the floor while bleeding.

Brake Bleeding Tutorial, Tips and Pictures - Bleed Brakes Like You Mean It - Honda Tuning Magazine

Its in the text right under the picture of the master cylinder push rod. Next time you want to argue do your research and don't argue with an Auto Tech. :rofl:
i cant beleive an autotech would say this. wow. By the way in the normal course of operation of a typical RL , or similar car with anti lockbrakes, in an extended stop in slippery conditions, the pedal may travel to the limit of pedal travel while under pressure, so what ihappens to the master cylinder piston? do you really think it never travels as far as it is designed to travel? hardly. Take one apart and look at it...anyway, fine for you to disagree thats what forums are for. Check out the GM workshop manual for this car it is sold as an A body book....
 

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The abs unit operates seperately from the master cylinder. Two different units entirely only connected by way of brake lines. The abs unit actually pushes the master cylinder piston back towards you if it notices the wheels are locking up during braking. The master cylinder piston hardly ever gets pushed all of the way. Thats why gunk builds up all the way at the end of its travel. How in the hell does this not make sense to you? Its quite simple.
 

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The abs unit operates seperately from the master cylinder. Two different units entirely only connected by way of brake lines. The abs unit actually pushes the master cylinder piston back towards you if it notices the wheels are locking up during braking. The master cylinder piston hardly ever gets pushed all of the way. Thats why gunk builds up all the way at the end of its travel. How in the hell does this not make sense to you? Its quite simple.
hey this is what happens. fluid in an abs apply is diverted under pressure through solenoids or valves in the hydraulic pump via an accumulator, on a pressure hold/release/apply basis, front wheels are sampled and treated individally, rear wheels on a "select low" basis; and as the pedal pulsates, indeed kicks back, it travels ever downward in stroke in an extended abs apply to the limit of pedal travel in extreme circumstances. The floor. If the master cylinder seal is nipped or damaged in the pedal stroke while bleeding then there is something wrong and to suggest that fully stroking the pedal while bleeding brakes can damage the cylinder because there is dirt or accumulation in the cylinder itself confounds me . How I am wondering can a hydraulic brake system work with dirt in it? I dont get this at all sorry.
 

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the rod in the master is attached to the pedal. pedal doesnt go to the floor the master doesnt travel all the way. done arguing. I know what happens. It has happened to me. Ive seen it happen to others. Ignorance is bliss but youll be kicking yourself when you push the pedal all the way to the floor while bleeding brakes on a car with some miles.
 

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the rod in the master is attached to the pedal. pedal doesnt go to the floor the master doesnt travel all the way.



exatly. what i am saying.


done arguing. I know what happens. It has happened to me. Ive seen it happen to others. Ignorance is bliss but youll be kicking yourself when you push the pedal all the way to the floor while bleeding brakes on a car with some miles.
see my reponse quoting you: we are in violent agreement. But yes, both pedals clutch and brake can reach the floor. look at the carpet..
 

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Wow, so now we dont push the pedal all the way down when bleeding brakes? WTF....thats news to me. Since the primary piston pushes the secondary piston you need fully depress the pedal to get full travel of both pistons during bleeding, this is in on car OR bench bleeding procedures. As far as corrosion in the master damaging the seal and casuing a mushy pedal....not likely, its much more likely that the crappy old fluid in the calipers was forced back quickly into the lines and BPMV during brake service, aerating it. Id do a full bleed again, and in the proper RR, LF, LR, RF order. if that doesnt work get a hold of a Tech2 and do a BPMV bleed.


Oh BTW I didnt bother to read any of your shadetree links but this is straight from the factory Service Manual:

Bench bleeding clinder

# Secure the mounting flange of the brake master cylinder in a bench vise so that the rear of the primary piston is accessible.
# Remove the master cylinder reservoir cap and diaphragm.
# Install suitable fittings to the master cylinder ports that match the type of flare seat required and also provide for hose attachment.
# Install transparent hoses to the fittings installed to the master cylinder ports, then route the hoses into the master cylinder reservoir.
# Fill the master cylinder reservoir to at least the half-way point with GM approved brake fluid from a clean, sealed brake fluid container. Refer to Fluid and Lubricant Recommendations.
# Ensure that the ends of the transparent hoses running into the master cylinder reservoir are fully submerged in the brake fluid.
# Using a smooth, round-ended tool, depress and release the primary piston as far as it will travel, a depth of about 25 mm (1 in), several times. Observe the flow of fluid coming from the ports.



Manual bleeding vehicle:
# Submerge the open end of the transparent hose into a transparent container partially filled with GM approved or equivalent DOT-3 brake fluid from a clean, sealed brake fluid container.
# Have an assistant slowly depress the brake pedal fully and maintain steady pressure on the pedal.
# Loosen the bleeder valve to purge air from the wheel hydraulic circuit.
 

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Okay,Now I actually went aread throught your links, you realize that 2 of the 4 links you posted specifically state to push the pedal ALL THE WAY TILL IT STOPS. or to leave bleeder open until fluid stops coming out, which in case you didnt understand fluid only stops coming out once piston has reached full travel.

As for the "Honda" link (lmfao) it states never to depress your pdal more than half way, GTFO this happens on the street in the course of a day, most GM vehicles are actually spe'd out to the have the piston travel 85% of its range.
 

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Okay,Now I actually went aread throught your links, you realize that 2 of the 4 links you posted specifically state to push the pedal ALL THE WAY TILL IT STOPS. or to leave bleeder open until fluid stops coming out, which in case you didnt understand fluid only stops coming out once piston has reached full travel.

As for the "Honda" link (lmfao) it states never to depress your pdal more than half way, GTFO this happens on the street in the course of a day, most GM vehicles are actually spe'd out to the have the piston travel 85% of its range.
gee thanks Maven to the rescue. I appreciate it man. Grand Master tech means sumthin'
 
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