Yes I know this is probably a beginner question...
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Racer
Joined: Sep 2008
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From: Tallahassee Florida
Yes I know this is probably a beginner question...
Yeah I know this is probably a rookie question but... I am changing my brake master cylinder and need to know how to bench bleed it before I reinstall the new one.. Thanks in advance for not giving me too much flack... 
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Thats a good article, but has anyone actually seen a bench bleeding kit at an autoparts store?
Anyone know a manuf or exact part number?
I'm going to need to replace at least 2 master cylinders this year, and maybe a third so having the "kit" would be a good thing to have (I have 3 older vehicles, 2 corvettes and a mustang if it matters)
Anyone know a manuf or exact part number?
I'm going to need to replace at least 2 master cylinders this year, and maybe a third so having the "kit" would be a good thing to have (I have 3 older vehicles, 2 corvettes and a mustang if it matters)
Race Director
Joined: Dec 2006
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Every master I've ever replaced has come with two hoses and two nipples. I suppose the only ones that don't come with the bleed kit are the AC/Delco.
Find a source for the kit but don't buy it until you see what is in the box with your new MC.
Race Director
Joined: Dec 2006
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The "normal way" is to bench bleed a master cylinder off the vehicle.
It is not impossible to bleed the MC by bleeding the cailipers but it isn't easy and will consume more brake fluid. I've seen several posts here over time where in people didn't bleed the MC off the vehicle and pulled their hair out trying to get a good pedal.
In this video the guy is able to bleed the master on vehicle because it is level. Notice the drip at the line! If you push the MC's rod too fast with those plastic nipples on they can pop right off. Slow will work fine tho.
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Safety Car
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From: Vero Beach Florida
You can bleed it on the car just as easy only it takes 2 people just bleed it before you reconnect to the lines get some real fittings that you use in place of the plastic fittings in the MC and bleed the system then attach the lines and check for pressure.
Last edited by floridamale; Aug 4, 2009 at 02:19 PM.
Le Mans Master
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onluy it's dangerous to your paint to bench bleed on the car incase of entrained air bubbles bursting out of the orifices and getting brake fluid on the paint.
Instructor
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I purchased it from a local auto parts store but this is the same one.
It was A little tricky to get the Cups,A vice sure did help.
http://shop.oreillyauto.com/ProductD...pe=230&PTSet=A
It was A little tricky to get the Cups,A vice sure did help.
http://shop.oreillyauto.com/ProductD...pe=230&PTSet=A
Le Mans Master
Joined: May 2006
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From: Irvine Ca
I listened to folks ONE time with the Bench bleed BS.
Wound up being a complete waste of 30 minutes.
Are we to suggest the the brake pedal does not get every bubble out? I ranted about brake bleeding before. And the reason being that it only takes me 15-20 minutes to bleed the system with one of my teenage boys or my wife pushing the pedal when I say push.....
Yet despite this success spanning almost 30 years, I continue to see these threads full of all kinds of ways to bleed the system.
"Push".....your helper pushes the pedal
You open the valve and let a little fluid out and close it quickly
Your helper holds that pedal until you say "release"
Repeat
You'll see clear fluid and bubbles come out when you are done
Move to the next wheel, repeat.
There is a special sequence for ABS brakes, and I don't know it off the top of my head.
I never touch those bench bleed hoses and fittin's.....
That's just my two cents.
Wound up being a complete waste of 30 minutes.
Are we to suggest the the brake pedal does not get every bubble out? I ranted about brake bleeding before. And the reason being that it only takes me 15-20 minutes to bleed the system with one of my teenage boys or my wife pushing the pedal when I say push.....
Yet despite this success spanning almost 30 years, I continue to see these threads full of all kinds of ways to bleed the system.
"Push".....your helper pushes the pedal
You open the valve and let a little fluid out and close it quickly
Your helper holds that pedal until you say "release"
Repeat
You'll see clear fluid and bubbles come out when you are done
Move to the next wheel, repeat.
There is a special sequence for ABS brakes, and I don't know it off the top of my head.
I never touch those bench bleed hoses and fittin's.....
That's just my two cents.
Le Mans Master
Joined: May 2006
Posts: 9,226
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From: Irvine Ca
lemme ask you something, this is nice video, but what happens when he pulls that red fitting off???
Wouldn't air get in the lines at that point?
So I'd like to know, if air is in the lines at the point where they connect to the master cylinder, what did the guy gain? He still has to move a bubble from that point to the release valve at the wheel cylinder and out the valve.
So He removed any bubbles from the MC plunger......what is that?? 1/4" gain in where the bubbles are located within the system?
Wouldn't air get in the lines at that point?
So I'd like to know, if air is in the lines at the point where they connect to the master cylinder, what did the guy gain? He still has to move a bubble from that point to the release valve at the wheel cylinder and out the valve.
So He removed any bubbles from the MC plunger......what is that?? 1/4" gain in where the bubbles are located within the system?
