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Old 01-03-2011, 12:31 AM   #1
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Not enough brake pressure

So my buddy and I did the ford 8.8 swap this weekend. Everything went well except for the brakes. The rear brakes do not grab like they should. We have the tires off of the ground and when the brakes r pushed in the rear tires still spin. But if I pump the brakes a couple times, the brakes will grab correctly. So it seems to us that there is a issue getting enough pressure. Any ideas or thoughts would be appreciated

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Old 01-03-2011, 12:33 AM   #2
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you have air in the brake lines. bleed them again, including the fronts. make sure you flush the entire system.

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Old 01-03-2011, 12:35 AM   #3
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Never did an axle swap but do you think you might need a new proportioning valve? Since the brakes went from drum brakes to disc brakes im guessing you would need different pressure for the disc brakes to work? Not sure.
Or you still might have air in the system which would make more sense cause that's exactly what the pedal does when your bleeding the system.
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Old 01-03-2011, 12:43 AM   #4
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We have flushed the whole system and have continued bleeding them with no luck. When we bleed the rears, the pedal does not go to the floor like it does with the fronts. As far as a new valve, I have not come across anything saying to swap in a different one. There have, however, been suggestions to remove the o ring out of the original proportioning valve.
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Old 01-03-2011, 01:50 AM   #5
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Update everyone:

So I came across another thread on this same issue. It had a link to a pirate thread that gave advice on this issue. I came across a small response in that two page thread that said, I had this same issue and it turned out that I put my brake calipers on upside down....Well guess what, we did the same thing. After we flipped the calipers, and rebled them, they worked amazing. Thanks again everyone, I hope this helps someone else in the future
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Old 01-03-2011, 02:04 AM   #6
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Yep, upside-down calipers from swapping them left-for right prevents them from being bled properly. When they are reversed, the bleeder is too low to let all the air out.
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Old 01-03-2011, 02:29 AM   #7
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I wish we had caught onto that screw up sooner. It was driving us nuts trying to figure out the issue, but we managed to get it. Little things like that can make you feel pretty dumb
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Old 01-03-2011, 02:38 AM   #8
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Heh, it happened to me too when I converted my rear axle from drum to disk. There's a 50:50 chance of getting it right, somehow it usually works out we get it backwards though. So much for the even odds of getting it right when we don't know any better.

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