So here's the gist of it, I'm having zero brake pressure when depressing the brakes. The car has a new master cylinder. I have bench bled the MC and bled all the brakes

When trying to bleed the front two wheels I don't get a lot of brake fluid coming out the bleeder valves and on the rear calipers I'll get a decent flow out of it. Not sure if I'm missing anything at this point
Maybe it's some stuck calipers on all wheels? Or what. Any advice or good word would be greatly appreciated 😀😀

 

If you are power bleeding as oposed to just putting your foot on the pedal and holding. Try the pedal method. One man bleeders do not really pass much fluid with the power bleed method.

I might just replace the fitting anyway, just to be sure.

If you have ABS, that is another can of worms. I am no help there.

 

Agreed. Have someone push the brake pedal. Open the nipple on the caliper, the pedal will hit the floor. Close the valve. Let off the brake pedal. Pump the brakes 3-4 times, then hold pressure on the brake pedal and repeat the process until the fluid is clean and there are no bubbles.

 

A new master cylinder? From where? It's new like actually new from mazda?

 

It's a MC from a Mazda 929.
Ill give bleeding the brakes another spin for sure..
Thanks again for your wizdom🧙

 

It's an MC from a 929
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Cool.... we've had people use the word "new" to describe USED parts. Technically they're right since it's "new" to them lol.

When installing an actually new brake master, even after bench bleeding, you have to do the bleed process at each caliper multiple times. When the system is completely dry especially with abs, air accumulates everywhere. An "initial bleed" as it would be referred is needed. So the process will be extended and the techniques varied based on how it responds.

Vacuum bleed, pressure bleed, pump and hold.... whatever you have to do so the system is purged. I usually gauge it by emptying the reservoir at least once per caliper. For an initial bleed, the order doesn't really matter until the flow is more uniform and then you do it from furthest to closest as you would with a "routine bleed".

its also possible the abs unit itself could be an issue. As we've noticed with brake parts that sit for some time, they dry out on the inside and don't hold pressure internally causing an infinite bleed situation. You will never be able to purge the system and even if you did, it wouldn't work. Same as if the brake master itself was bad.

 

Now to touch on what you had said about the abs, how would I go about ruling that out as my culprit.. have a whole day to try n figure this out, many thanks!

 

You either rebuild it or remove it

There is no troubleshooting. It would be best to thoroughly exhaust your bleeding options before going with either option.