Master Cylinder???
Thread Starter
Racer
Joined: Sep 2002
Posts: 388
Likes: 0
From: somewherein Ar
Master Cylinder???
I was sick of the gray, gloomy and cold weather this weekend, so I decided to spend the whole time in my garage doing some things from my Vette to do list. I put new brake pads (EBC Greenstuff) and new rotors on the front, and stripped the nappy-looking clearcoat from my stock 90 rims and polished them. After I put the wheels back on front and lowered it, I noticed I had a spongey brake pedal, so I then bled the lines at the calipers. This helped alot, but the pedal still felt a little spongey. After further checking I noticed a small amount of brake fluid directly under my master cylinder on the power booster housing. Does that indicate the MC is toast and should be replaced or is there some sort of seal on the MC where it mates up to the power booster that needs replaced? Thanks in advance for any suggestions.
Racer
Joined: Feb 2004
Posts: 471
Likes: 0
From: Boston MA
Re: Master Cylinder??? (Red90Coupe)
If the car had been sitting a while (no break use) then sometime you can lose some of the pressure in the lines and get spongy breaks but a few touches on the pedal should get things working again....if bleeding the lines helped and you and you noticed a small bit of brake fluid (bad stuff on paint so watch out) under the MC sounds like you have a cracked line or seal issue around the where the lines go into the MC.....i would look around for that crack and go from there. What kind of break lines do you have?? Hope this helps......
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Re: Master Cylinder??? (Red90Coupe)
I was sick of the gray, gloomy and cold weather this weekend, so I decided to spend the whole time in my garage doing some things from my Vette to do list. I put new brake pads (EBC Greenstuff) and new rotors on the front, and stripped the nappy-looking clearcoat from my stock 90 rims and polished them. After I put the wheels back on front and lowered it, I noticed I had a spongey brake pedal, so I then bled the lines at the calipers. This helped alot, but the pedal still felt a little spongey. After further checking I noticed a small amount of brake fluid directly under my master cylinder on the power booster housing. Does that indicate the MC is toast and should be replaced or is there some sort of seal on the MC where it mates up to the power booster that needs replaced? Thanks in advance for any suggestions.
Sounds like you are about to ned a Master Cylinder. Brake fluid on the booster would be coming from the main bore of the cylinder which is seals and O rings.
Fluid below the MC on the frame, would probably be coming from the brake lines.
I disagree that a spongy pedal is synonymous with not using the brakes in a while. This is a closed hydraulic system, not a vented one! There should be no air in the system, regardless of how long you let the brakes set, unless of course they have set so long as to allow deterioration.
Pumping the pedal only overcomes, temporarily, the air in the system.
OOPS! Did you, at any time you were bleeding the brakes, let the reservoirs on the MC get low on fluid? This will introduce air into the system but should not result in fluid visible unless you spilled it
:seeya
:steering:
Thread Starter
Racer
Joined: Sep 2002
Posts: 388
Likes: 0
From: somewherein Ar
Re: Master Cylinder??? (jackdaroofer)
OOPS! Did you, at any time you were bleeding the brakes, let the reservoirs on the MC get low on fluid? This will introduce air into the system but should not result in fluid visible unless you spilled it
Thanks for the input guys. :cheers:
Le Mans Master
Joined: Oct 2000
Posts: 6,362
Likes: 30
From: Oak Harbor WA
Re: Master Cylinder??? (Red90Coupe)
No, not hard at all. Make sure you have a set of line wrenches. You don't want to have to replace a brake line unnecessarily.
You'll have to bench bleed the MC before you install it then bleed the system out again.
You'll have to bench bleed the MC before you install it then bleed the system out again.
Team Owner
Joined: Jan 2003
Posts: 20,324
Likes: 250
From: Summerland B.C. Canada
Re: Master Cylinder??? (Red90Coupe)
Sorry to hear about the loss of your MC :smash:
I noticed mine had the same leak. My replacement has been sitting on the floor waiting it's turn :D
Now on to those wheels.
Would you have a pic of them stripped and polished ?
:cheers:
I noticed mine had the same leak. My replacement has been sitting on the floor waiting it's turn :D
Now on to those wheels.
Would you have a pic of them stripped and polished ?
:cheers:
Thread Starter
Racer
Joined: Sep 2002
Posts: 388
Likes: 0
From: somewherein Ar
Re: Master Cylinder??? (AGENT 86)
Now on to those wheels.
Would you have a pic of them stripped and polished ?
:cheers:
Would you have a pic of them stripped and polished ?
:cheers:
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Burning Brakes
Joined: Oct 2001
Posts: 1,135
Likes: 17
Re: Master Cylinder??? (Red90Coupe)
did you add fluid to the reservoir ? if so are you positive that you didn't spill some brakefluid..
BTW: regarding those EBC Greenstuff - be prepared to do some serious wheel cleaning! Also they last about 5k Miles :rolleyes: They do grip VERY wel l Though!! :yesnod: :yesnod:
:seeya
[Modified by Daniel DK, 5:43 PM 2/10/2004]
BTW: regarding those EBC Greenstuff - be prepared to do some serious wheel cleaning! Also they last about 5k Miles :rolleyes: They do grip VERY wel l Though!! :yesnod: :yesnod:
:seeya
[Modified by Daniel DK, 5:43 PM 2/10/2004]
