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Bleeding the MC

2413 Views 8 Replies 4 Participants Last post by  random84
After about 10 months of being unsure about my brakes being where they should be, I’ve decided to take on the task of bleeding the MC. I keep hearing so much about “Bench bleeding” it. I get how it’s done, what I want to know is, can’t I do the same bleeding process with it still on the car? Undoing the brake lines, hooking up the plastic adapters, tubes, and then pump the brake pedal? Without pulling it off and using the vise to do all of that? Seems the same to me, but maybe I’m missing something.

Note: After replacing the brake lines last month, the brakes seemed fine, got in the other day and the pedal was real spongy again. I’ve bled these brakes prob 20-30 times, including several ABS bleeds with Scan tool. Still seeing micro bubbles coming out right front outer bleeder screw. Also replaced all 8 bleeder screws yesterday with Speed bleeders. So today I’m gonna hit the MC, but would rather leave it on if possible.
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Yes you CAN, just not as easily as if you were bleeding a new one before putting it in, on your bench.
Yes you CAN, just not as easily as if you were bleeding a new one before putting it in, on your bench.
What makes it more difficult? Our MC seems pretty open and has enough room to work. As long as you have someone to pump the brakes
That's about it. If it's in a vice on your bench, you can just push the cylinder by yourself as you watch the bubbles and fluid level. If you have another person to help, it shouldn't be bad.
That's about it. If it's in a vice on your bench, you can just push the cylinder by yourself as you watch the bubbles and fluid level. If you have another person to help, it shouldn't be bad.
That’s what I thought, just makin sure I wasn’t missing something. I’m about to put the wheels back on to test what I did yesterday and if that didn’t do the trick, MC is next.
You May remember last February when I drained the whole system by accident and had many issues. Since then, I changed the brake lines and have never felt the brakes were where they should be, regardless of how well they were working and stopping. My gut told me it wasn’t right. Let’s see how this goes. Thanks bro
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Did you put a mity vac on the brake reservoir and pull vacuum first? Might be easier than pulling the whole thing (much like a clutch)?

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Any news? I’m having similar issues where I let the MC run low during fluid change. Now my back brakes are doing 90% of the stopping
Any news? I’m having similar issues where I let the MC run low during fluid change. Now my back brakes are doing 90% of the stopping
Are you still seeing any bubble’s or micro bubbles at all when bleeding the fronts. I ended up bleeding the ABS system several times which most likely didn’t need to. How I solved my problem was to just BLEED BLEED BLEED!! So many times I couldn’t even remember how many times. On the last time i did it, I drove my car the next day and low and behold, I finally noticed a big difference in the brakes. Yes they were working good enough to drive and safely stop at anytime, but something told me they just weren’t right. So I went back and bled them again and again until the last time they finally worked. I kept seeing micro bubbles and assumed those needed to be out. Which they did. It cost me a lot of brake fluid but the persistence paid off. Again, bleed bleed bleed, test drive, then bleed bleed bleed until they work properly! That’s my advice.
Note: I have a Motive bleeder but seemed to work best with someone (my wife) pushing the pedal the old fashioned way. Pack some patience bro! Good luck! Let us know how they turn out!
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Any news? I’m having similar issues where I let the MC run low during fluid change. Now my back brakes are doing 90% of the stopping
You probably have air in the ABS actuator - which is a bitch to fix. You either take it to a dealer so they can use a tool to activate it (pump the air out), or do a lot of hard stopping on slick surfaces like gravel or ice, then rebleed the lines.

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