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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.

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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 you're saying I should vacuum/pressure bleed the calipers unmounted from the rotors?

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Could this braided line orientation be causing some issues?

 

 

One thing I noticed that helped me isolate my problem (air in the caliper) was my fluid level dropping in my rear master as I pumped the brake and then slowly returning as the trapped air pushed the fluid back ti the m/c.

 

It's possible for the front and rear to leak to each other. If you have this situation and pump the pedal a lot you'll see the front master reservoir filling up and the rear going empty. It could also pump fluid into the booster.

You'll make a lot more progress if you get methodical and test each potential problem area individually.  There's three areas right here, above.  Test each one -

 

1.  Eyeball the hose while someone pumps the brakes.  Does the line expand like it's collecting fluid?  It's probably not orientation but it could be a bad hose.  I've not seen any red brake hose, where did it come from?

 

2.  Watch the reservoirs as someone pumps the brakes.  Which reservoir is moving more fluid?  That's the system that has air in it.  Unless... 

 

3.  Watch the fluid.  Does it transfer from one reservoir to another?  If so, your master cylinder is messed up.  Does it drop and never come back?  If so, you have a leak, either internal or external.

 

You have enough clues now to focus on exactly where the source of the problem is.  You just have to pick one area at a time and dig in to each one.

Edited by NewZed
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You'll make a lot more progress if you get methodical and test each potential problem area individually.  There's three areas right here, above.  Test each one -

 

1.  Eyeball the hose while someone pumps the brakes.  Does the line expand like it's collecting fluid?  It's probably not orientation but it could be a bad hose.  I've not seen any red brake hose, where did it come from?

 

2.  Watch the reservoirs as someone pumps the brakes.  Which reservoir is moving more fluid?  That's the system that has air in it.  Unless... 

 

3.  Watch the fluid.  Does it transfer from one reservoir to another?  If so, your master cylinder is messed up.  Does it drop and never come back?  If so, you have a leak, either internal or external.

 

You have enough clues now to focus on exactly where the source of the problem is.  You just have to pick one area at a time and dig in to each one.

 

1. I doubt they expand, at least on the driver side from what I can see, the lines were custom made as are the fronts from a local tube n hose shop.

 

2 & 3. I am unfortunately on my own. So I don't have anyone unless I ask a neighbor. I'll try tomorrow.

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Set up a mirror so that you can in the reservoir.  Put a little boat in there with a flag on it that you can see moving up and down.  Something.  I have a broken shovel handle that is perfect length for actuating the clutch and brake pedals.  I use it all the time for bleeding.

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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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  • 2 weeks later...

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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