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So I had someone pump them with the caps off, and I noticed the front reservoir does not move however the rear reservoir goes down when the brake is held and when released it comes back up. So does that mean the air is in the rear line? Also with all the modding in the brake system would I have had to change the bias?

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... the rear reservoir goes down when the brake is held and when released it comes back up. So does that mean the air is in the rear line?

Quantity matters also.  There shouldn't be a huge imbalance between the two though.  The rear reservoir may be supplying the front brakes.

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Yeah you have air in the rear system, again the most likely in the calipers.

Your bias is going to change whenever you change brake systems, tire sizes, pad composition, weight distribution etc etc. I pulled my proportioning valve to eliminate the possibly of it giving me problems during my trouble shooting knowing that I would have to add an aftermarket adjustable one later.

 

Oops, double post

Edited by Naptown Dave

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I think your flex line is ok as long as the bleeder screw is above the flex line inlet on the caliper. I would bet a stack you have air trapped in the calipers. Remove the calipers and turn them so the bleed screw is the highest point and bleed again. I got a bunch of air out of mine even after doing the same thing while gravity bleeding, mine needed the flow of the pressure bleeder to push out the air. Take the caps off the master and watch the fluid level as you pump up the brakes, you'll see the level drop in the master if you have air in either the front or back systems. Mine only needed the back but it was enough to have a soft pedal.

 

So I gave this a shot today, and still no progress. I should mention when I take my pressure/vacuum bleeder to the front calipers, I get solid fluid draining out of the calipers. When I hook it up to the rear calipers I only get a trickle of fluid coming out of the calipers. like its restricted. When the bleeders are open and someone presses the brake pedal, they drain as they should. So I feel confident there is no clogs in the line.

 

Quantity matters also.  There shouldn't be a huge imbalance between the two though.  The rear reservoir may be supplying the front brakes.

 

Would it be supplying the front calipers from the master then if it were bleeding through? Because when the brake pedal is pressed the front caliper reservoir does not go up or down, only the rear reservoir.

 

The 18th I'm taking this into a brake shop and letting them take over. I'll keep making attempts to figure this out until then, but I'm running out of theories. I'll try taking a video too today of what both front and rear calipers are doing while I am bleeding them giving you guys a visual of the problem.

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Because when the brake pedal is pressed the front caliper reservoir does not go up or down, only the rear reservoir.

This doesn't sound right.  Sounds like your problem is in the master cylinder, maybe a blown seal on the front brake master cylinder piston.  Even with no air in the lines, there is fluid movement,  just not the large quantity you would see with air in the lines.

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UPDATE:

 

So I purchased a new caliper for the one that was torn, replaced it, gravity bled, vacuum/air bled system, still no pressure...

 

I'm a bit at odds to replacing the M/C, I just replaced what I was sure was the problem and its still not working, I don't really wanna go buck wild with replacing every component, its getting expensive.

 

on a side note of stupid questions: A vacuum leak on the motor wouldn't cause a pressure problem with the brakes through the booster would it?

 

EDIT: I seemed to have also forgot to mention that I get pressure after bleeding prior to starting the Z, but soon as I start it up all that pressure is gone... is this a clear indication of a bad booster? Which seems odd to me because its like it was fine one second and bad the next.

Edited by Daphur280

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You could try removing the line to the calipers, pressing the pedal and seeing what comes out.  You need to isolate down to sub-systems.

 

Don't forget also that the "pressure" when using the Mighty-Vac method is atmospheric.  It's everywhere.  So, for example, if the bleeder on the other caliper was open, or if there was a leak there, the vacuum method would pull from there instead of the reservoir.  Wherever is easiest.  When you use vacuum to pull, it's not exactly the same as using pressure from the MC to push.

 

As for isolating components, I've fabricated small rubber plugs to fit under the fitting for pressure checking.  Just stick it in there, tighten the fitting slightly and that caliper or cylinder is locked out.  You can use that to test the MC.

 

You could also rig up an old piece of brake line and run it directly from the MC in to a container if you want to see if the MC is pushing any fluid.  Or use the bench bleeding ports, that's what they're for.  Again, taking the calipers out of the picture.

 

In your video, you have everything in the brake system connected, and you're trying to figure out what's wrong by watching fluid run through a tube out of a caliper.  Too many things interacting at one time.  Isolate down to something manageable and visible.

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I got some new fexible brake lines and cut the fittings off of them. Took them to a welder and had them brazed closed. I now use those as test plugs to isolate components. I also use them to cap lines if I have a component like a caliper off to keep brake fluid from drip, drip, dripping. Takes a couple lunch hours to get all those errands run, but they are great.

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Here are a couple of brake diagnosis flow charts that may help isolate the problems you are having. Make a check list and go back through your brake system part by part and take notes.  Be methodical.  Check off each item as you complete them.

 

Here are some things that may help:

 

  • Verify that the MC is properly bench bled and that it holds pressure (plug outllets with 10mm x 1.0mm plugs and push the MC piston)

 

  • Verify that after you checked for the reaction disk that it did not fall out while you were doing things to the MC. It happens.

 

  • If you have not done so, use JB weld and glue the reaction disk to the push rod. No more worrying if it fell out.

 

  • Adjust the MC push rod to where it almost touches the bottom of the cup it sits in. You can just pull the MC off the booster leaving the hard lines connected and push it aside while you adjust the push rod. Test fit the MC and adjust the rod out until you feel the MC spring back and then keep adjusting the rod inward and fitting the MC until the MC no longer springs back. Test drive to make sure the rod is not too far out which will cause your brakes to drag and lock up.  It is easy to adjust the push rod  if you have cleaned and lubricated the threads on the push rod.

 

  • When installing a bench bled MC, block the ouput ports with rubber plugs to eliminate fluid leaking out and air getting back inside while installing it. Also, block the tank openings with large rubber stoppers to keep fluid from flowing anytime you have a line open or installing the MC.

 

  • Use a Motive Power pressure bleeder  pumped up to about 20psi and flip/move/shake/tap  the rear calipers in all possible positions while fluid is flowing.  There are a number of places inside the caliper where air can get trapped.  Go here for the Motive Power Bleeder:  http://www.motiveproducts.com/

 

  • Of course verify that the fronts are completely bled after installing the MC.

 

  • After verifying all air is out of the system with the Motive  Power bleeder install Earls Solo bleed screws (spring loaded valves) in your MC and calipers. Why? because the power bleeder flows better with the stock bleed screws and the Earls solo bleeders will make future brake work much easier. Don't use the crappy solo bleeders ( Russell) that use sealent on the threads.

 

  • If you do not have the reaction disk in place and the push rod properly adjusted your brakes will feel soft with a long pedal which will make you think that there is still air in the lines.

 

 

Welcome to the 10 gallen brake fluid club.

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post-178-0-03633000-1383361265_thumb.gif

Edited by Miles

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Did you remove check valve in MC?

10.jpg

 

Am I suppose to keep those off or remove them for bleeding?

 

Did you say there is a hissing sound? I had that problem when I changed to the ZX 15/16 mc and found I had a leaking diaphragm in the booster . I replaced it and she works good now

 

The diaphragm or the whole booster? I hear he hiss at the last 1/4 of the brake pedal press, did you hear it the full length of pressing the pedal or...?

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So the Z hasn't sold and I had some time to tinker, I took another shot at the brakes.

 

1st: I removed the check valves in the MC:

 

Did you remove check valve in MC?

10.jpg

 

2nd: Bench bled the MC and made sure that everything was well plugged until I reconnected it to the lines.

 

3rd: Adjust the push rod about 3/4 turn out

 

4th: Was not able to JB weld the reaction disk to the push rod, but it felt snug in there when I return the rod back into place, I'm assuming its good because I had to clock it in toe get it seated all the way.

 

5th: I have some un-named brand pressure bleeder that works similar to Motive power bleeder minus the adjustable pressure regulator. I thought about getting one and connecting it between the bleeder and the coupler, but I was going to wait to see what happen after this attempt.

 

6th: Installed spring loaded bleeder screws an all 4 corners (don't remember the brand but there not Russell)

 

7th: Re-bled the system

 

And success!  :icon10: There is still a bit of distance in the pedal, before it went to the floor with almost no pressure and needed to be pump 3x to attain brake pressure, this time around I only need to press about 5/8 to get a good amount of grab. 

 

Pretty much following Miles and tamo3's advice solved the issue.


 

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