Rusty Brake fluid?

[mrnapolean1]

I am in the process of bleeding all four brake lines on my 92 GMC.

The brake fluid is like a black color with an orange tint. I had to replace two bleeder bolts because I had to remove them with Vice grips and they looked like they had trash and rust in them.

What causes this and is it possible to restore my brake system to its former glory?

 

[michael hurd]

If it's that bad, I would want to do a bit more than just try to bleed them. Sounds like you had a pile of moisture and rust inside the system. To be honest, I would want to change the master cylinder, calipers and wheel cylinders as a bare minimum, after flushing out the steel lines as best you can with clean fluid. ( empty and clean the reservoir on the old master cylinder, refill and gravity bleed first )

 

[highspeed]

If it's that bad, I would want to do a bit more than just try to bleed them. Sounds like you had a pile of moisture and rust inside the system. To be honest, I would want to change the master cylinder, calipers and wheel cylinders as a bare minimum, after flushing out the steel lines as best you can with clean fluid. ( empty and clean the reservoir on the old master cylinder, refill and gravity bleed first )

This. Possible inspect the rubber brake lines as well. Black stuff in the fluid suggests deteriorating rubber parts breaking away and dissolving in the brake fluid.

 

[mrnapolean1]

Master Cylinder is 1 year old and its clean as a whistle. I have no clue how old the Wheel cylinders/Front calipers are.

Brakes where working just fine before I had to break the system to install new rear end.

Id figure I would bleed them till all of the black/orangish brake fluid is out.

 

[RichLo]

Since the rear end is broken already, you should probably rebuild or replace those wheel cylinders. they're cheap and easy enough.