Brake Woes

[Miles]

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.

Edited November 2, 2013 by Miles

[Daphur280]

Did you remove check valve in MC?

 

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...?

[Miles]

For your own safety I recommend that you take the car to a brake shop and let them sort things out for you. You are not going to solve the problems on-line.

[Daphur280]

For your own safety I recommend that you take the car to a brake shop and let them sort things out for you. You are not going to solve the problems on-line.

 

I took it to one already, they said they won't work on it and I got hit with a $75 tow bill, I'm on my own -_-'

[Miles]

Sell the car.

[Daphur280]

its on craigslist

[NewZed]

Have you considered putting the original brake parts back on? 

[Daphur280]

Have you considered putting the original brake parts back on? 

 

I had brake cylinders which were shot, the backing plate I cut off, the master cylinder was used as a core, as were my front and rear calipers...

[Daphur280]

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?

 

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!   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.