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mrdew

Brake Problem Please Help

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Long story short this brake system minus the front brakes were on another vehicle and performed well. The front brakes are larger than factory, but bleed easily and seem to relieve all air from the system.

When driving the pedal travels all the way to the floor with minimal effort and barley stops the vehicle from a crawl. When bleeding the system the pedal never gets hard. I have installed two master cylinders both with identical results.

Notes:

-The pedal never gets hard

-There is no fluid in the vacuum booster

-I have installed TWO master cylinders to see if there was a change

-I have power/pressure bled, vacuum bled, manually bled, and gravity bled the system.

-The pedal travels to the floor every time with minimal effort, the master cylinder is completing a full stroke.

-There are no leaks in the system

I am stuck at this moment and would like any advice I could get!

Thanks

Dan

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When you pump the pedal, can you eventually get a pedal?

Or does it just pump and pump?

t

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try a NEW master cylinder for the third time
99% of the time the problem comes from unproper bleeding. The 1% remaining is caused by a user installing the calipers upside down. I'm not kidding.

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Did you bleed the master out first? sometimes air gets trapped in the master and is very difficult to remove when bleeding the system as a whole.

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Same issue and questions for me too!

What year is your car? Does it have a Brake Pressure Switch 34321115861 and do these things fail?

Did you bleed the MC first? Pressure the system and crack open the connection on each of the hard lines. Be prepared for the mess.

I'm having the same issues after upgrading front and rear to 320i with all new/rebuilt parts. 2 New Tii MC (first one was defective = blowing bubbles) and calipers right side up. Pressure bled MC and lines multi times.

What is the correct distance between pivot points on the rod from pedal to booster?

Doug

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mrdew:

Did you solve your braking issue? My brakes were similar and after bleeding the top two hard lines at the MC a second time I must have finally got all the air out and now can lock up all four corners (well 3 out of four - still some adjusting to do). Give it a try.

Good luck,

Doug

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Doug, what do you mean you bled the hard lines at the MC? I just did a big brake upgrade in front, and the pedal is a little soft I think. I've bled all four points several times since the system drained when I had the calipers off. I think I might still have a bubble.

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Dan,

This is a long shot, but you mentioned that the front calipers are not stock but are in fact bigger. A buddy and I, some years back, installed a big brake upgrade on his 2002, and went for three days and seemingly gallons of DoT 4 trying to bleed. Then it dawned on us the the calipers were upside down. The left caliper had been mounted on the right side of the car, and the right caliper on the opposite The bleed valves are supossed to be oriented "up". Once we remounted them on the correct side of the car, all was well.

Earl

74 02Lux

02 M Roadster

72 Volvo 1800ES

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As a follow-up I put 10psi on my pressure bleeder and had the wife push the pedal to the floor (traditional bleeding method) at the same time, about 3 times each bleeder, and was able to liberate the final air bubbles in the MC.

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Just did my master cylinder this weekend. I had discovered that a PO had installed a passenger side caliper on the drivers side, so yes, it is upside down. Not ready to buy new ones yet, and since it works fine in operation, I just add a step to the bleeding process, remove caliper and turn it right side up before using the power bleeder. It works...

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Sorry about the delay for the update, but I was able to locate a master cylinder same day and it did make the pedal a little better. I disconnected the vacuum booster and it now seems to want to stop it half decently, I was able to lock up a wheel or two today when I got on the brakes to see what would happen.

I believe that my car has 320i front brakes (the PO had them on the car), originally when I got the car they were mounted to the back of the front wheel with the bleeders facing up. Without thinking I installed them towards the front of the car but swapped sides and the bleeders are facing up in this orientation. If I had pictures I would gladly share.

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