No Brakes After New MC and Bleeding

BigSlappy

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Sep 4, 2022

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Buffalo, New York

Feb 13, 2023

#1

• Feb 13, 2023

• #1

Just installed a new MC and bled the brakes, but now i have worse of a pedal. Theres no leaks around the brakes. I cannot figure out why I cant get a stiff pedal that goes straight to the ground anymore. Can anyone throw some suggestions? Kinda lost on this.

 

nickyb

I gotta say i never painted my nuts, Never Ever

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Feb 13, 2023

#2

• Feb 13, 2023

• #2

Did you bleed the mc? Should be done before install but possible to do after.

 

BigSlappy

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Buffalo, New York

Feb 13, 2023

#3

• Feb 13, 2023

• #3

nickyb said:

Did you bleed the mc? Should be done before install but possible to do after.

Click to expand...

pretty sure its bled correctly. had someone brake while i tightened the lines a couple times. No air comes out anymore, unless if im doing it wrong.

 

T

TimC

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Apr 24, 2022

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Feb 14, 2023

#4

• Feb 14, 2023

• #4

Nickyb is asking you if you BENCH bled the mc BEFORE you installed the mc. It is a critical step to get the air out of the mc, before you attempt to get the air out of the lines after mc installation. Bench bleed it. Youtube is your friend.

 

Reactions: nickyb

Mustang5L5

That is…until I whipped out my Bissell

Mod Dude

Feb 18, 2001

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Feb 14, 2023

#5

• Feb 14, 2023

• #5

You have the bench bleed the MC to purge the air out before installing it. The MC is installed on the car at an angle that traps air at the end, which is why it's usually done off the car where it can be held level.



Did you change the MC or brakes to a different type? Sometimes, too large of an MC bore, or too large of a caliper will also result int he pedal feeling way too soft or spongy.

 

R

Rcdgl

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Feb 14, 2023

#6

• Feb 14, 2023

• #6

Try bench bleeding the mc before installing, per the above.

Then do the farthest wheel first, etc.

I put all new brakes on a car, and had to vacuum bleed with a Mityvac and finally a Motion Power bleeder to get enough fluid to finally pedal bleed. Pita.

 

BigSlappy

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Buffalo, New York

Feb 14, 2023

#7

• Feb 14, 2023

• #7

Ended up re bleeding all the lines on a whim. for some reason, the passenger side caliper has an enormous amount of air in it. No other line had air in it so it was a little strange. My brakes are all good now, either than the fast the brake booster doesnt like to do its job lol.

 

manicmechanic007

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Feb 18, 2023

#8

• Feb 18, 2023

• #8

The master cylinder bench bleed procedure takes 20 or more pumps (to get all the air out of the new master cylinder)
Then once you install it on the car it takes a few more pumps to get the system bled
That is if you do everything right
You, in this case, just need to go about 40 more times, and then you'll start getting some pedal

 

manicmechanic007

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Feb 18, 2023

#9

• Feb 18, 2023

• #9

You did that and got them working
Next time put the new master cylinder in a vise and with fluid in it, pump it a bunch of times with your fingers pressed into the ports, or use the bleed kit tubes and fittings that come with it
Pros like me use fabricated brake lines to feed air into a container of new brake fluid
That makes it even easier

 

Last edited: Mar 23, 2023

BigSlappy

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Buffalo, New York

Feb 18, 2023

#10

• Feb 18, 2023

• #10

manicmechanic007 said:

You did that and got them working
Next time put the new master cylinder in a vise and with fluid in it, pump it a bunch of times with your fingers pressed into the ports, or use the bleed kit tunes and fittings that come with it
Pros loke me use fabricated brake lines to feed air into a container of new brake fluid
That makes it even easier

Click to expand...

Probably should have lol. Thing took forever to bleed.

 

manicmechanic007

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Feb 19, 2023

#11

• Feb 19, 2023

• #11

We had 95 Broncos at the dealer that took days to bleed out after replacing the ABS HCU

 

90sickfox

Wasn't a pretty sight...and I've got big hands

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#12

• Feb 25, 2023

• #12

manicmechanic007 said:

We had 95 Broncos at the dealer that took days to bleed out after replacing the ABS HCU

Click to expand...

We used to take them out of the shop and slam on the brakes while driving on dirt. It would make the ABS kick on and push the air out. Those old Ford trucks were a PITA to bleed.

 

manicmechanic007

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Feb 26, 2023

#13

• Feb 26, 2023

• #13

Good idea
That works if you have enough pedal for a test drive
The ones I remember used quart after quart of brake fluid
Once you got some pedal, the process quickened up and you were done

 

BigSlappy

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Buffalo, New York

Mar 7, 2023

#14

• Mar 7, 2023

• #14

manicmechanic007 said:

Good idea
That works if you have enough pedal for a test drive
The ones I remember used quart after quart of brake fluid
Once you got some pedal, the process quickened up and you were done

Click to expand...

Came back to the car after a week or 2 to see the brakes perfectly fine lol. I do notice the brake booster is bad from what i assume the leaking MC. The brake work though!